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Message started by DragBikeMike on 10/14/22 at 16:53:02

Title: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 16:53:02

There are three weak points in the cylinder head fasteners. Two of them I see frequently on this forum, exhaust stud holes strip and head cover holes strip. The third I have not seen mentioned on the forum, but I have personal experience with the 8mm stud that secures the head to the cylinder (just below the exhaust port).

I have come up with a fix for each of those weak points. This post provides the details.

What I am about to describe worked good for me. If you decide to try this stuff on your own, you assume responsibility for the outcome. If you don’t have the skills, don’t do it. If you don’t understand something, STOP and get help. Get a manual. Read up. Comply with ALL the safety requirements outlined in the manual. Make sure you know what you are doing before attempting any of this stuff.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 16:55:43

The header pipe is secured to the cylinder head with two 8mm bolts. They are decorative bolts that simulate the appearance of a stud with an acorn nut. The key point here is that these fasteners by design are “Bolts”.

Here you see an imitation stud & nut. It’s really a bolt.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 16:57:11

Stripped threads can result from cross threading or overloading.

Get the threads cross threaded and continue to turn the fastener and voila, you chew up the threads on the weaker material. The weaker material in this case is the cast aluminum cylinder head. Bad news because that head costs a helluvalot more that the cheesy bolt.

Overloading the threads is generally connected to thread engagement. Thread engagement determines the total shear stress area of the thread system. More engagement equals more shear stress area. More shear stress area equals more resistance to shearing. When using a steel fastener in an aluminum component, you generally want engagement on the order of two to three fastener diameters. So, for an 8mm stud installed in an aluminum component, you should expect at least 16mm thread engagement, 24mm would be better. Let’s face it, wouldn’t you prefer that the cheap stud snap off rather than the threads pull out of the super-expensive head.

When you are juggling with the head pipe, flange, and fake studs, it’s very easy to cross thread the fastener into the cylinder head. It’s also easy to get the collar on the head pipe cocked such that you can hardly achieve any thread engagement. It’s not cross threaded but its only in the hole maybe two or three turns. Then, thinking everything is cool you start turning the fake stud with a wrench. Under these circumstances, you either wreck the internal threads by forcing the misaligned bolt into the hole, or you overload the internal threads because of the insufficient engagement. Voila, wrecked head.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 16:59:59

The fix, use real studs with nuts. With real studs, installation is not a juggling act. You install the studs when there is easy access, and you aren’t struggling with the head pipe, flange and bolts. You can easily see when the stud is fully inserted and be confident that there is adequate thread engagement.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:00:47

Yep, I know it’s not as pretty. But its better, lots better. Its stronger. Its easier to install the head pipe. It can hack the mission. Use stainless steel nuts if you want to dress it up a bit.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:01:17

These Dorman studs work perfect. Available at your local O’Reilly Auto Parts.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:02:57

Any of you ever seen one of these? That would be your typical head cover bolt. You know, the long ones that secure the right-hand side of the head cover. There are three of them (115mm, 125mm & 130mm). I’m always seeing reports about these fasteners on the forum. They love to yank out the internal aluminum threads. You can see this one was in there real deep, and the internal threads still sheared. IMO, the aluminum fatigues over time. The repeated thermal cycles take their toll. It’s not a crossed thread issue. Pretty hard to cross thread a bolt that’s being aligned by a hole that’s over 100mm deep. I’ve had two of these fail, and I don’t overtighten fasteners.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:04:02

You can fix the front-right (115mm) and the central-right (125mm) with the engine still in the frame and the cylinder head still installed. Just drill through the head cover, head, and cylinder with a ¼” drill bit. You will need a long bit and it will not actually remove material from the head cover or the head. Just drill straight through the cylinder using the head cover and head as a guide. I know this picture shows the engine on a workbench, but you can do the job with the engine in the bike, zero problemo.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:04:56

Then you install a ¼-20 UNC Grade 8 bolt with a grade 8 nut. Major league strong. On the front-right and center-right bolts, there’s no risk of putting aluminum chips into the engine. Just take appropriate precautions to keep things clean. For instance, you wouldn’t wanna do this with the clutch cover off, or the oil filler cap removed.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:05:46

You will have to grind a bit on the underside of the cylinder fin to provide a flat and square surface for the nut to bear on, and to provide room for the nut to rotate. Very easy to do with a small grinder (Dremel tool).

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:07:22

The right-rear head cover bolt (130mm) is another story. Unfortunately, I believe it’s the one that fails most frequently. The right-rear bolt goes through an oil passage. Any sort of drilling will put metal chips into that oil passage. If you wanna fix that one you need to remove the cylinder head to block the oil passage and clean things out after the repair is finished. I use plumbers’ putty to seal off the oil passage in the cylinder. Then temporarily reinstall the head and head cover to use as a guide for the drilling operation. Then remove the head cover and head to clean things up. This can be done with the engine still in the frame, but the head and head cover must be removed for cleanliness plugging and cleaning.

Because the bolt hole is pressurized with oil when the engine is running, the bolt-head must be sealed, and the nut on the bottom must also be sealed.

A standard Suzuki sealing washer works fine under the bolt-head. I apply a dab of silicone sealant too.

You can’t use a standard nut on the bottom. It will leak. You need to use a closed nut, like an acorn nut.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:07:57

I want a lot of strength, so I make my own acorn nut out of a grade 8 bolt. I get more thread engagement that way. But I suspect a standard acorn nut will work fine. I incorporate an o-ring into the special acorn nut to make the seal. I want to be able to take this fastener up to maximum allowed stress to ensure a good head gasket seal at the oil passage.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:08:33

To provide a decent sealing surface for the acorn nut, you need to apply a spotface. Hand grinding won’t do. One of these cheap valve seat cutter tools works well. The cutter kit comes in handy for other stuff too. You only need the cutters, the handle, shaft and guide won’t be needed.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:09:09

You can get the cutter kit at any decent hardware store. Amazon sells them too.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:10:05

Once you have drilled the hole through the cylinder, you need to relieve the cooling fin just below the location that the acorn nut will bear on. That will provide room for the spot facing tool, and also the nut.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:10:40

The cutter bits have a 6mm tapped hole in the center, so you can drive the tool bit with the old 6mm head cover bolt. You will have to clean up the threads in the cutter bit with a M6-1.00 tap so that the threads go completely through the cutter. It’s tough material but if you go slow and use cutting oil you can carefully run the tap completely through the cutter. Start the tap from the back side of the cutter (side with no cutting blades).

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:11:21

This is what it looks like in action. You lock the cutter to the bolt with a jam nut. Use copious amounts of mineral spirits as a cutting lubricant to keep the cutter blades from loading up with aluminum. Remove the cutter frequently to clean the aluminum chips out of the blades. In a few minutes you will have a nice, flat spot face.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:12:00

Finished spot face. Ready for action. Now remove the cylinder head, clean out all the aluminum chips, and remove your cleanliness barrier (plumber’s putty, modeling clay, etc.). Put everything back together. New head gasket will be needed.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:13:00

This sucker takes a lickin and keeps on tickin. You can rest assured in the knowledge that your head gasket will get pinched adequately to keep the oil where it belongs.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:14:15

Have any of you ever noticed that your 8mm head nut, the one just below the exhaust port, always seems to come loose? Mine is always coming loose.

One reason is that the stock steel MLS gasket tends to sink into the aluminum cylinder head. Just a bit. With the stock head gasket, you usually find the area just under the exhaust port won’t clean up. There always seems to be a witness mark that corresponds to the embossed fire ring in the head gasket. Always on the exhaust side, never on the intake. But that nonsense stops once the head has conformed to the fire ring.

See the witness mark. It doesn’t clean up unless you resurface the head. That means it has depth.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:15:23

Another reason is that the 12mm threads in the aluminum cylinder head are giving up. How do I know that? I keep finding my studs/inserts proud.

This is my Stage 3 head after a little over 6500 miles and several nut tightenings. The tool bit catches on the edge of the stud. It was well below the sealing surface when I installed the head. So, the stud insert now interferes with proper head gasket crush. No good.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:16:22

Here’s my Stage 2 head after about 14,000 miles and four or five re-tightenings. You can really see that insert sticking up. It’s proud by about .007”. That’s gotta be bad.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:17:00

You can see how the insert is bearing hard on the head gasket.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:17:39

And you can see how the stud makes the head gasket bear hard on the cylinder. Look at the impression.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:19:08

What’s goin on?

IMO, another case of fatigue. The condition is aggravated by removing the stud to resurface the head. The stud, by design, has a class 5 interference fit into the aluminum head. Remove the stud to resurface the head and you end up with a class 3 or 4 fit. Not as robust. Now increase the cyclic stress by bumping up the compression 2 points from 8.5:1 to 10.5:1. The horsepower goes way up and so does the break mean effective pressure. The head gets subjected to a lot more force. Now open up that exhaust port and decrease the structural integrity of the head. Takes a lot less force to bend it. Throw in a pile of red-hot exhaust gas, get the whole shebang cycling about 2000 to 3000 times per minute, and guess what gives up.

All is not lost, hope springs eternal. Maybe the thing can be salvaged, possibly even improved.

We start with our trusty valve seat cutting tool. Let’s make a counterbore inside the exhaust port and install an insert the other way, with the shoulder on top. So now, the shoulder does all the work, not the threads.

Take the old stud out. That can be hard. I had to drill mine out. Don’t exceed a 27/64” drill and make sure you are perfectly centered. Then clean up the threads with a M12-1.25 tap. Not too bad. Should work.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:19:45

Make a guide by drilling through a M12-1.25 bolt (grade 8.8 is fine, soft enough to drill). You will use it with a long M6-1.00 bolt to drive the cutter while keeping it centralized and square.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:20:18

Install the guide in the stud hole. Use washers/spacers as shown to set the depth. You want a nylon or fiber washer in contact with the head surface to prevent damage to the sealing area.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:21:04

Install the cutter and jam nuts as shown. Start with a smaller cutter (.55”) and then finish with your final size cutter. The finished size will depend on the insert you choose to use. I made my own insert. It had a .615” diameter flange, so the .63” cutter was just right. You want the counterbore to be about .015” larger than your insert flange, so that the insert can be threaded all the way into the counterbore. And you want the counterbore to be about .08” (2mm) deep. The depth will depend on the insert you use.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:21:47

You can drive the cutter assembly with a cordless hand drill set to slow speed. You turn it in reverse (CCW). Again, use copious amounts of mineral spirits to prevent the aluminum from loading up the cutter, and clean the cutter blades frequently. Only takes a few minutes to do the job, even with the interruptions for cleaning. You end up with this. Nice.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:22:25

I made my insert from a grade 8.8 bolt, M12-1.25. Soft enough to permit machining on my jalopy lathe, but waaaaaay tougher than the aluminum casting it was goin in. It had M12-1.25 external threads, M8-1.25 internal threads, and the flange is .615” O.D.. The flange is about .08” thick. I have also made similar inserts from the stock stud by sawing off the 8mm shank and then drilling and tapping the 12mm base with M8-1.25 internal threads. The flange O.D. is a bit smaller (.55”) but it would probably work. Just adjust your counterbore cutter to suit.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:23:09

To install the insert you will need some simple tools. An easy out, a continuously threaded M8-1.25 bolt, an M8-1.25 nut, several spacers, and an appropriate wrench.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:23:52

I use the easy out to help install the insert from inside the port. I don’t reef on the easy out, just use it to align the insert and turn it to thread it into the hole. Do a trial fitup to make sure it goes all the way home.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:24:50

Once the insert is started into the threads, remove the easy out and replace it with the M8 bolt and install a nut on the top. Now you can use the wrench to run it in snug.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:25:49

It must go all the way in and hit the bottom of the counterbore.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:26:27

If it fits good, remove the insert, clean everything up with Braklean, apply a coat of JB Weld to the external threads, and reinstall the insert permanently. Go easy with the epoxy, you don’t want any slopping up the M8 internal threads.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:28:14

If done correctly, it should look like this. Just a smidge of epoxy peeking out from around the flange of the insert. The insert is all the way home.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:29:52

Once the epoxy cures, that sucker ain’t ever comin out so make sure you got it right. If your lookin for a little better performance you can blend the insert in with a die grinder, but I doubt it ill make much difference. The gas flow through this port at WOT is pretty much confined to the upper regions of the port. I’ve tried a number of mods to the floor of the port, and they don’t make any difference on the poor man’s flow bench.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/14/22 at 17:30:38

No more interference with the head gasket. Use one of those Dorman M8 studs with the insert and you have a good strong fastener. I have this installed on my Big Bore 4-Speed project and it’s ready to go. I have a high degree of confidence in this fix, but the old Savage has fooled me a time or two. I will keep you informed.

Title: Re: Cylinder Head Fastener Upgrades
Post by verslagen1 on 10/14/22 at 19:49:34

61676814161115250 wrote:

Could you explain this further?
http://suzukisavage.com/yabb2.2/Attachments/Acorn_Nut_Oring.JPG

Title: Re: Cylinder Head Fastener Upgrades
Post by TheSneeze on 10/14/22 at 20:25:11

Lathe work. A blind threaded hole in the center, with a counterbore for the o-ring. Flats are machined into the outside diameter so you can tighten it with a wrench.

Must be fricken nice to have a lathe! (totally jealous!)

Title: Re: Cylinder Head Fastener Upgrades
Post by justin_o_guy2 on 10/15/22 at 10:04:22

That is some seriously clever problem solving. Yeah, having a lathe is something I really want, but IF I had one, I'm not sure I have the skill to get it to do something like that.
Probably some Kinda learning curve goes into THAT.
Good stuff, Mike.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 11/10/22 at 12:40:31

Versy, I’m sorry I missed your question. My comment on desiring maximum stress at the right-rear fastener is related to the oil feed to the head. I had trouble on one with a 97mm bore and copper head gasket. Big oil leak at the right-rear corner. That problem was caused by the head not being perfectly flat. But having a fastener in that location (right-rear head cover bolt) that could not be reefed on to the max didn’t help. You just can’t twist up that stock bolt since you will end up yanking the internal threads out of the cylinder. Using the grade-8 through-bolt with a nut eliminates the need to girl thingy foot around the fastener. You can max up the torque, and if it breaks just replace the bolt & nut.

I hope that explains my comment. If you were looking for a sketch LMK and I will do a quick drawing.

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 11/10/22 at 12:42:26

I’ve been running the Big Bore 4-speed for about one month. The engine has about 1900 miles on it. I wanted to fill you in on how the fastener modifications are working out.

The ¼-20 head cover bolts are solid. No leaks along the joint between the head cover and head. The special acorn nut is also dry as a bone. I knew this repair works good since I’ve run it on other engines. This fix is a keeper.

The 8mm cylinder head stud just below the exhaust port is also solid. I check the nut about once per week and the nut is always tight. At most, I may have rotated this nut a total of 1/20 of a turn (18°) in all my retightening attempts combined. With the old setup, I generally got about 1/8 turn (45°) every time I checked it until the shoulder on the stud started touching the head gasket, at which point the fastener was no longer clamping the head to the cylinder. I think this mod is a must for anyone running a 97mm bore and the enlarged exhaust port. The copper head gasket associated with the 97mm bore is unforgiving. It doesn’t have an embossed bead to compensate for any reduction in fastener stress. The enlarged exhaust port reduces some of the beam-strength between the 9mm studs, so a solid 8mm stud in the center is critical.

I am very pleased with these repairs/mods.

Title: Re: Cylinder Head Fastener Upgrades
Post by verslagen1 on 11/10/22 at 14:10:53

1F19166A686F6B5B0 wrote:

I hope that explains my comment. If you were looking for a sketch LMK and I will do a quick drawing.

I got the gist of what it was from sneezes comment. thanks.

Title: Re: Cylinder Head Fastener Upgrades
Post by Ikarus on 03/06/23 at 10:53:36

Hello and first of all thanks for the great solution. My right rear bolt has failed and have a major leak from it. Going to try your fix. When you say that the head must be removed for sealing of the oil passage and clean up does that mean the cover at the top or the top section of the head where the fins start. If so this is probably the most involved and complex repair I have done on the bike. Do you recommend the clymer manual as a way to help me get it done? Thanks again.

Title: Re: Cylinder Head Fastener Upgrades
Post by Moarpower on 03/06/23 at 20:06:59

Have to ask. Ive had one of the longer cylinder head bolts stripped when I bought my bike. I uesed a longer bolt.
It was the one to the rear of the engine on the right side. This one also has an oil passage.

Isn't there a risk of drilling through that and getting aluminium into the engine?

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 03/06/23 at 23:50:24

Ikarus, yes you should have a service manual. Even for the simplest repairs and maintenance, a service manual is a "must have" tool.

To do the repair I describe, or to install a heli-coil as Dave suggested, you must remove the head cover, camshaft, and cylinder head. Either repair requires drilling and the metal chips will need to be cleaned out. In addition, you need to block off the oil passage in the cylinder to keep the chips from goin down the chute. It's a fair-sized job but well worth the effort.

The heli-coil looks cleaner and maintains the stock design; the through-bolt & nut is stronger. The heli-coil requires the kit with special tap, drill bit, insertion tool, and inserts; the through-bolt & nut requires the long grade-8 bolt, acorn nut, long 1/4" drill bit, and the valve seat cutting tool. Either repair is good. I prefer the through-bolt for the added strength and ease of future repair.

Moarpower, does this reply answer your question.

Title: Re: Cylinder Head Fastener Upgrades
Post by Ikarus on 03/07/23 at 18:51:47

Yes it does and thank you so much.

Title: Re: Cylinder Head Fastener Upgrades
Post by Gus on 03/10/23 at 15:04:35

There's some serious mecha-nicking going on here! Nice to have all these free design workarounds at our disposal.
Thanks to many of you.

Title: Re: Cylinder Head Fastener Upgrades
Post by och on 08/10/23 at 19:28:15

Stripped my 130mm valve cover bolt. There is no way I'm taking this engine apart to fix it, wondering if a 140 or 150mm long bolt would work?

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 08/11/23 at 12:47:10

You need to take it apart to fix it.

Title: Re: Cylinder Head Fastener Upgrades
Post by och on 08/12/23 at 19:34:20

Mike, first I have to say huge thanks to you on doing all the research and posting the information on how to do the bolt upgrades the right way. At the very minimum I will install the exhaust studs since it is so easy to do.

That being said, I hate to beat the dead horse but I am desperately looking for a way around fixing the stripped 130mm bolt hole without taking the head off, I just dont have the time or the knowledge to do it right.

I have just measured the 130mm bolt, and it is actually 128.5mm. I've got a 140mm bolt, and I got it to thread into the hole, however I'm only able to thread in 133mm until it bottoms out, with 7mm remaining. Thus, 133-128.5 = it catches 4.5mm of thread, which might just be enough.

So I am considering my options, out of which there are many.

With the 7mm of the 140mm bolt height remaining I can make a 6mm aluminum spacer with a sealing washer on both ends and bolt it down.

I could also gently drill and tap deeper into the block with the risk of introducing metal shavings into the oil passage - there are probably already some metal shavings from the original damaged thread anyway. I see the hole sleeve within the block is about 140mm long, so I gotta be careful not to drill right through - maybe drill down to 138mm and then tighten the bolt with a smaller spacer and sealing washers.

I could also drill right through and blow out most of metal shavings, tighten the bolt all the way down and use sealer on the bottom of the hole to prevent potential leaks.

I fully realize all of these options are not the right way to do the job, but in a pinch, which is the lesser evil?

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 08/13/23 at 19:16:31

"Thus, 133-128.5 = it catches 4.5mm of thread, which might just be enough."

You won't have 4.5mm of thread because you can't allow the end of the bolt to bottom in the blind hole. If you let the bolt bottom you will most certainly jack-out the remaining threads. So, at best you will have maybe 4.0mm of thread engagement. That's a steel bolt in aluminum internal threads.

The general rule for thread engagement is a minimum of one bolt diameter. So, a 6mm bolt needs at least 6mm of thread engagement. But that general rule assumes external and internal threads of the same material (steel bolt in steel internal threads). You have aluminum internal threads and I suspect the mechanical properties of that aluminum don't even approach 50% of the grade 10.8 metric flange head bolt.

Your bolt and bolt hole are an integral part of your lubrication system. This is a bad idea. You need to take the cylinder head off and fix it correctly.

Title: Re: Cylinder Head Fastener Upgrades
Post by och on 08/15/23 at 18:14:38

Mike, against your recommendations, I went and drilled through the block without removing the head, and tapped it right through. I did a thorough job blowing out all the shavings, so in that aspect I think I am ok. I put in a 140mm bolt in there, and its almost flush with the bottom of the hole, i think the sealing washer is keeping it about 1mm higher.

I only ran the bike for a few seconds, and made a humorous video in the link below. I believe the rattle is gone, which is a good thing, but there is a new problem - a tiny drop of oil formed at the bottom of the bolt. I figured this might happen as this bolt is going through an oil passage which is pressurized. I have cleaned around the hole and applied some permatex gasket maker, hoping it will hold up. With roughly 12mm of new thread the new bolt is going through, I don't think there is much pressure left at the end of the bolt. If not, I will use a 150mm bolt with a sealing washer and acorn nut on the bottom.

https://www.youtube.com/watch?v=iZaPx5houCE

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 08/17/23 at 01:39:26

Congratulations. I guess there's more than one way to skin a cat. 8-)

Keep us posted on how it works out. This whole mess started with a clutch problem, and then seemed to sort of spiral out of control. So, how is the clutch working now?

Title: Re: Cylinder Head Fastener Upgrades
Post by och on 08/17/23 at 20:09:55

01070874767175450 wrote:

Didn't have the time to even ride it yet, had to go to NC for family business, wont test it until next week.

Title: Re: Cylinder Head Fastener Upgrades
Post by och on 08/27/23 at 16:51:44

No updates in a long time, but I havent had the chance to ride the bike until today, and even then I only rode it for about a minute around my block. Here is the good, the bad, and the ugly.

The good is the rattling sound is gone, the engine sounds great, and pulls strong. The clutch is now working properly, no dragging, and neutral is easy to find with the engine on and off, no more sticking when shifting 1-2 and 2-1. The sealed head bolt did not leak, but I'll have to give it a longer ride to be truly sure.

The bad is 10 seconds into the ride I heard a vibrating nose that immediately amplified. This time it was easy to discover - I have replaced my timing inspection port plug with the DRZ plug, for ease if removal in the future as it uses a 10mm allen bolt vs a long flat slot on the stock plug. Turns out the new plug did not come with a gasket, and I forgot to swap in the old one, so the plug immediately loosened up. Very easy fix.

http://https://i.imgur.com/QdfA03Q.jpg

Here comes to ugly. I took off the plug to swap in the gasket, and keep in mind the plug is brand new with only 2 laps around my block. I looked inside the plug and there was a ton of metal shavings in it, and some shavings inside the port hole. I cleaned the shavings, took the bike for one more lap around the block, removed the plug and there were more shavings, but this time a lot less than the first time. I inspected the old plug, and there were no shavings in it whatsoever. There was no shavings inside the port hole when I removed the plug to set the engine to the TDC. Also, when I drained the oil to work on my clutch, I did not see any shavings in it either, therefore these are new shavings that got there within the 1 minute that I was riding the bike around my blocks.

The shavings are probably from me redrilling the head bolt that goes through an oil passage - and therefore I probably deserve what's coming for not taking the advice to do it the right way. I thought I blew most of them out, but I guess not. I'm very surprised how fast they made all over the engine, I imagine if I found them in the port hole, they are probably all over the engine as well. I'm also surprised that these shavings seemed to be dry, not covered in oil - almost if they got blown in there by air. Could they have got there when I was blowing them out with compressed air through the head bolt hole?

That being said, I will keep removing and inspecting the port plug during for the foreseeable future. Would it be a good idea to do a few oil changes with some cheaper oil ever 50 miles or so to try and get the shavings out?

http://https://i.imgur.com/5dKeMSD.jpg

http://https://i.imgur.com/u6V5F82.jpg

Title: Re: Cylinder Head Fastener Upgrades
Post by TheSneeze on 08/27/23 at 21:42:15

I think you just created one heck of a problem! IMO that engine is now on borrowed time. How long it lasts is a crap shoot. Best of luck...

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 08/28/23 at 02:00:02

I'm thinkin your alternator rotor bolt is rubbing on that new timing plug. That assessment is based on the location of the chips, the fact that the chips are dry, and your fuzzy picture. Can't tell for sure from the pic, but it sure looks like the bolt has been rubbin on the inside of the timing plug. That plug has raised casting material on the inside face. As I recall, the stock plug is flat. Put the two plugs side by side and take a nice clear photo, then post the photo.

Title: Re: Cylinder Head Fastener Upgrades
Post by och on 08/28/23 at 03:47:45

I dont know why it did not occur to me, I guess so much frustration with all the issues lately I automatically assume the worst possible scenario. Thank you Mike, I will double check both plugs and if anything I'll machine down the inside of the new plug a bit. This is also how it got loosened up so fast, the engine turns counter clockwise so it caught and turned the plug.

Title: Re: Cylinder Head Fastener Upgrades
Post by Dave on 08/28/23 at 04:15:27

You should have ordered a timing cover for a Suzuki Intruder if you wanted chrome, or a DR650 if you want painted.

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1416070003

Title: Re: Cylinder Head Fastener Upgrades
Post by och on 08/28/23 at 04:26:31

7C474A5D4C405B5D464E435C2F0 wrote:

You should have ordered a timing cover for a Suzuki Intruder if you wanted chrome, or a DR650 if you want painted.

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1416070003

I did not care for painted or chrome, I just wanted allen bolt as I really struggled to remove the slotted one.

Title: Re: Cylinder Head Fastener Upgrades
Post by och on 08/28/23 at 04:28:54

Just checked, 09259-36008 is what I bought on Amazon.

Title: Re: Cylinder Head Fastener Upgrades
Post by Dave on 08/28/23 at 08:33:50

0F0308600 wrote:

Just checked, 09259-36008 is what I bought on Amazon.

Well don't buy any more of them....they obviously don't fit!

3438335B0 wrote:

I did not care for painted or chrome, I just wanted allen bolt as I really struggled to remove the slotted one.

Well according to the listing on Amazon - you did buy one that is chrome. If you had bought the one for the Suzuki Intruder it would have fit properly and not made shavings in your engine.

On my bike I used the painted DR650 plug. I stripped off the paint and then polished the aluminum to match the LS650 case (no chrome).

Title: Re: Cylinder Head Fastener Upgrades
Post by och on 08/28/23 at 13:26:19

I'll just machine down the inside of the plug that I bought. It might also have been cause by the fact that I did not put on the gasket the first time around, with the gasket there should be more clearance. I'm still baffled how it didn't occur to me right away what was happening.

Title: Re: Cylinder Head Fastener Upgrades
Post by Dave on 08/28/23 at 14:23:09

These timing covers should only be made lightly "snug" when they are installed - not "tight:.

Folks over-tighten them, and that is why they are hard to remove.

The rubber O-ring seals them up, and also keeps them from vibrating loose.

Same for the drain plug.....snug them up one handed - don't tighten them like a wheel lug bolt!

Title: Re: Cylinder Head Fastener Upgrades
Post by och on 08/28/23 at 15:44:44

0B303D2A3B372C2A3139342B580 wrote:

Title: Re: Cylinder Head Fastener Upgrades
Post by verslagen1 on 08/28/23 at 20:35:09

616D660E0 wrote:

[quote author=0B303D2A3B372C2A3139342B580 link=1665791582/60#65 date=1693257789]These timing covers should only be made lightly "snug" when they are installed - not "tight:.

Folks over-tighten them, and that is why they are hard to remove.

The rubber O-ring seals them up, and also keeps them from vibrating loose.

Same for the drain plug.....snug them up one handed - don't tighten them like a wheel lug bolt!

My original plug was never removed before, so it was very tight from the factory - i really struggled with a huge screw driver and a hammer to get it loose. I figured an allen key plug is going to be easier to remove if I have to in the future. I'm not very particular about its finish, im a function before form person.
[/quote]
besides the over tightening, once done it brings metal to metal contact around the perimeter of the plug and gives a chance to cold weld the parts together making it almost impossible to remove.

replace the o-ring once it becomes compressed.

Title: Re: Cylinder Head Fastener Upgrades
Post by Surviving Philly on 08/29/23 at 12:27:55

Regarding the use of dorman studs for the header --

If you have a wrapped pipe be mindful of potential difficulty with seating the collar on the studs correctly. I just did this today and ran into some unforseen issues as a result.

DBM did you torque the studs? I know they bottom out in there, I'm concerned that over tightening on the supplied nuts could over torque the studs in the head. What are your thoughts?

Thanks

Title: Re: Cylinder Head Fastener Upgrades
Post by och on 08/29/23 at 12:46:56

08392D343637343936580 wrote:

You are much more likely to strip the threads inside the aluminum block with the stock bolts.

Title: Re: Cylinder Head Fastener Upgrades
Post by och on 08/30/23 at 04:57:58

Finally took the bike out for a ride after all the repairs, and it runs like a champ! No leak from the headbolt, no more rattling or ticking noises, great power, the clutch does not drag, no sticking when shifting gears, easy to find neutral. I'm very happy to finally have the bike to proper!

Title: Re: Cylinder Head Fastener Upgrades
Post by TheSneeze on 08/30/23 at 07:14:25

I would change the oil and filter soon to try and get as much of those drill shavings out of that engine. Hopefully none are getting where they could cause problems later on. But another flush and filter certainly couldn't hurt.

Title: Re: Cylinder Head Fastener Upgrades
Post by och on 08/30/23 at 08:17:27

76694C4B414844574E250 wrote:

I honestly dont think any shavings made it in there, most of the shavings from the cap ended up in the cap, I cleaned them out. And the head bolt, I drilled it slow and blew all the shavings out of there, I think I am in good shape now. Just so glad to have the bike running as its meant to.

Title: Re: Cylinder Head Fastener Upgrades
Post by TheSneeze on 10/23/23 at 13:10:40

76707F03010602320 wrote:

DBM - You wouldn't happen to know how to identify the OEM P/N for this Suzuki sealing washer?

Title: Re: Cylinder Head Fastener Upgrades
Post by och on 10/23/23 at 15:18:56

https://www.mcmaster.com/products/sealing-washers/oil-resistant-rubber-sealing-washers/

Title: Re: Cylinder Head Fastener Upgrades
Post by DragBikeMike on 10/23/23 at 20:21:41

It's the same sealing washer used on the head cover bolts and the three clutch cover bolts. OEM part number is 09168-06023.

OCH, that McMaster & Carr gasket is solid rubber. You can't stress the fastener properly because the rubber will deflect. The OEM gasket is a neoprene insert surrounded by a metal ring. When you tighten the fastener the rubber deflects until the fastener contacts the metal ring. Then the fastening system is metal-to-metal and you can properly stretch the bolt.

Title: Re: Cylinder Head Fastener Upgrades
Post by och on 10/24/23 at 08:14:13

Good to know. When I used longer bolts, I reused the stock sealing washers.

Title: Re: Cylinder Head Fastener Upgrades
Post by TheSneeze on 10/24/23 at 10:46:40

Thanks, DBM!