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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> Loud knocking, I'm going in... /cgi-bin/YaBB.pl?num=1330112933 Message started by singlesgoinsteady on 02/24/12 at 11:48:53 |
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Title: Loud knocking, I'm going in... Post by singlesgoinsteady on 02/24/12 at 11:48:53 I bought my '98 (5700 miles) for a street tracker conversion. It had a loud knocking sound (does not sound like chain lash). The sound is like heavy metal hitting heavy metal deep inside. You can feel it in the bars. The knock is NOT there at idle, but, with any throttle it comes on then gets drowned out by typical motor noise at high rpms. It does sound like it could be a valve smacking something, but, from what I read there is a gap between the piston and valves at TDC. So maybe it's a loose bearing or wrist pin. It just seems so unlikely for a motor with so few miles on it. I already checked the cam chain tensioner and had an extension welded on. It was out quite a ways, like 0.61". I borrowed a boroscope and my next step is to look in the cylinder, bottom of valves and top of piston for signs of damage. Then take the valve cover off and look for damage and the valves and check the gaps. After reassembly and firing up, if it still knocks, I guess time to take the head off. If you have any suggestions, let me know. Thanks guys. |
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Title: Re: Loud knocking, I'm going in... Post by justin_o_guy2 on 02/24/12 at 16:04:54 Drain the oil into something clean a magnet wont stick to. Run a magnet thru it & see what kinda metal you get. |
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Title: Re: Loud knocking, I'm going in... Post by verslagen1 on 02/24/12 at 17:33:41 Most likely wouldn't last long if the valves and piston were fighting. I had an '88 with a knock, turned out to be a burnt piston. you could see it from the top, little melted section. colapsed on the rings. |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 02/24/12 at 20:29:03 I got the boroscope in the sparkplug hole, amazing technology. Cylinder looks good, I can see the arrow on it and I can see the arrow on the piston top. Piston top is clean and shiny except one big quarter size looking spot of oily carbon gunk. But, one intake valve looks like it has a little chip out of the edge. Exhaust valves are white, lean? Intake valves look black and sooty. Waiting to hear from a friend tomorrow to confirm if I'm seeing a chunky off the valve, but, otherwise it looks like time to yank the motor... Any thoughts are appreciated. See my sketch below haha. |
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Title: Re: Loud knocking, I'm going in... Post by Boule’tard on 02/24/12 at 21:01:47 Interesting project. Sorry for the captain-obvious question but have you checked the valve timing. Maybe it jumped a tooth before you fixed the cam chain tensioner? I'd replace both intake and both exhaust valves, since you have a suspected collision on an intake valve and the exhaust valves may have gotten excessively hot. A few savages have dropped exhaust valves, probably because of the heat. See if the white spacer mod has been done on your bike.. if not, do that and bump the main jet up one. |
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Title: Re: Loud knocking, I'm going in... Post by justin_o_guy2 on 02/24/12 at 22:11:05 LOng version both intake and both exhaust Short version All Four |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 02/24/12 at 23:29:14 Roger all of that guys. Bout'tard: I did the valve check, but, may in my unfamiliarness have done it in the intake TDC, but, it ran the same as before, feeling rather gutless. Will check again before head removal. P.S. long live Trailer Park Boys. |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 02/24/12 at 23:30:30 What is estimated time for engine removal for a Savage newbie? |
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Title: Re: Loud knocking, I'm going in... Post by Boule’tard on 02/25/12 at 07:12:17 Maybe one of those Ryca conversion guys like MotoBuddha will know how long it takes. |
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Title: Re: Loud knocking, I'm going in... Post by verslagen1 on 02/25/12 at 07:55:10 I've done it in 2 hours, but I've done it a few times. ;D |
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Title: Re: Loud knocking, I'm going in... Post by Retread on 02/25/12 at 09:00:08 Burnt valve, too lean... |
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Title: Re: Loud knocking, I'm going in... Post by justin_o_guy2 on 02/25/12 at 09:07:18 Ive seen a couple of Quick Cheap Easy engine stands from some of these guys,,IDK where the pics are, Sounds like youre gonne be wantin to build one. |
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Title: Re: Loud knocking, I'm going in... Post by Retread on 02/25/12 at 09:13:30 This stand took about thirty minutes.. http://farm8.staticflickr.com/7183/6911048291_ba75e6cf7d.jpg It uses the stock engine bolts and holes for mounting.. |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 02/25/12 at 09:48:44 Engine stand, haha I wish. I'm in an underground parking garage in my apt bldg. This could suck...but a good learning experience ;D |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 02/25/12 at 17:58:02 It's all coming along, thank god for Clymers. Got it ready to dismount. It was a pregnant dog getting some old phillips screws out and unflattening those washers, not to mention getting the belt nut off. Crescent wrenches prevailed, however. Head/cylinder off Monday to see what's in there... A savage buddy also suggested taking the bottom end into the local Suzuki dealer to see if they think the bearings are okay, since we never determined the cause of the loud knock. |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 02/25/12 at 17:59:39 Ha ha, I see my Windows 7 on my new laptop automatically changed "pregnant dog" to "pregnant dog". WTF, big brother... |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 02/25/12 at 18:00:59 F-*-C-K !!!! B-i-t-c-h !!! it did it again ! |
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Title: Re: Loud knocking, I'm going in... Post by verslagen1 on 02/25/12 at 18:30:16 big brother yabb |
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Title: Re: Loud knocking, I'm going in... Post by Mattdw on 02/27/12 at 09:08:53 32282F262D2432262E282F323524202538410 wrote:
This question may be a bit late, since you already took it all apart, but, did you check all the motor mounts to see if that was the source? I bought an '02 Savage, only had 6k miles on it. All was fine, until you rev'd her up...then the whole bike would rock and roll and vibrate your teeth out. Turned out the top motor mount bolt was loose. But the symptoms made you think the whole bike was about to fall into pieces. Tightened up the bolt, and voila...no more vibration. |
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Title: Re: Loud knocking, I'm going in... Post by justin_o_guy2 on 02/27/12 at 09:51:26 Eaux Neaux! & Yea,, thats a possibility,, |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 02/27/12 at 11:24:46 This question may be a bit late, since you already took it all apart, but, did you check all the motor mounts to see if that was the source? I bought an '02 Savage, only had 6k miles on it. All was fine, until you rev'd her up...then the whole bike would rock and roll and vibrate your teeth out. Turned out the top motor mount bolt was loose. But the symptoms made you think the whole bike was about to fall into pieces. Tightened up the bolt, and voila...no more vibration. I almost snapped an allen wrench and some cheap sockets trying to get those bolts out, she was tight as a... tight. Thanks though. Can anyone tell me what size socket I need for the belt drive nut/bolt? I had to use a massive crescent wrench which made me really nervous. |
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Title: Re: Loud knocking, I'm going in... Post by drums1 on 02/27/12 at 11:27:14 From what he was describing, it sounds like more than a loose bolt on a motor mount. But oh, wouldn't that suck, if that was all it was, after having removed and disassembled the motor? Keep us informed as to what you do find. I think that bolt is a 31 or 32 mm..... |
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Title: Re: Loud knocking, I'm going in... Post by Mattdw on 02/27/12 at 11:29:12 584E49514F0D3C0 wrote:
Mine behaved exactly like that...there was a range of the rpms that shook like crazy. |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 02/27/12 at 11:42:32 302621392765540 wrote:
It would suck bad, don't even joke about that... |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 02/27/12 at 22:12:38 Okay, cylinder off and no catastrophic carnage. The boroscope was wrong, no burnt valve. Only thing I can see is some piston top scratches from my screwdriver while checking TDC and some slight discoloration on the RH exhaust valve. However, I noticed the rod is has a wee bit of side to side play on the crank. Being a teardown newb, I have no idea if this is normal or not. I assume it could be the source of my knocking, but, there also must be a hair of play there just from the pounding it takes. Bottom end guys, let me know what you think. You can see the pics below, they don't show much. A hair of scoring on the cylinder, but, I assume that's normal, no major gouging. It's either roll the dice and re-ring and hone, or buy a 2nd hand motor. What's the call, I'm all for getting this project on the road, maybe having a spare motor isn't all that bad. I'm just dreading putting a used motor in and hearing the same thing. You'd see a grown man cry :'(. |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 02/27/12 at 22:13:02 And the valves: |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 02/27/12 at 22:40:53 706661796725140 wrote:
Thanks, it was a 32mm, picked one up tonight. |
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Title: Re: Loud knocking, I'm going in... Post by ratz on 03/01/12 at 12:45:23 Might want to check your piston skirt and the ring land clearance. I just did the top end on an S40 with 10000 miles with the same knock you described. Apparently,the person he got it from got it good and hot at some point,caused the piston skirt to oval and deposit aluminum in the bottom of the bore.The ring grooves compressed enough to hang the rings up as well. The pictures you posted could have been pictures of the one I did.Looked good up top,cylinder bore looked good,problems were from the ring grooves down! |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 03/01/12 at 22:46:28 6774616F7B736774727B150 wrote:
Thanks. Ya, I have not found any smoking guns, as in visible impact damage, but, my valves look WAY different than SillyDilly's. His were all wet and greasy (maybe rich, or normal), mine are black, sooty and the exhaust valves pure white from heat. So it was lean and hot for sure. I'm getting new rings and will hone it out, but, otherwise, I'm hoping it's just a valve adjustment/timing issue that cause the knock and that it will go away when I get it back together. I'm having a buddy look at the bottom end as best we can without splitting cases first too. |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 03/09/12 at 20:18:11 So I got it all apart and had my engine buddy take a look. All is in spec tolerance, but, I noticed the pin had a bit of friction when in the rod. Closer inspection revealed a pitting area that seems to cause some binding in the pin/rod connection. It seems the pin could bind or at least have resistance in the rod which I'm assuming could make the whole piston wear more heavily while in motion. You can see the wearing groove in the pics. Also, does ART make the stock pistons or is this an aftermarket piston? I'm going to look at a used motor tomorrow. I don't think this wear would cause the knocking sound, but, it could indicate that something more is going on and splitting the cases just seems impractical for the cost and effort and the risk that it never gets back together as good as factory anyway. Bummer. I will not be defeated... ;D also see the pics on the following page. |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 03/09/12 at 20:19:02 The ART piston |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 03/09/12 at 20:19:28 the piston groove where the pin sits |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 03/09/12 at 20:19:56 the wear on the rod. That groove in the rod lines up with the groove in the pin and the groove in the piston. |
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Title: Re: Loud knocking, I'm going in... Post by MMRanch on 03/10/12 at 07:33:00 do you think you found the sourse of the knock yet ? Mine has a knock also, it only sounds off under throdle . I'm taking the exaust off , to make sure its sealed and open today. I wonder if we had or have the same problem ? |
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Title: Re: Loud knocking, I'm going in... Post by justin_o_guy2 on 03/10/12 at 07:58:42 I watched a guy put a BIG diesel engine together that had some pretty deep divots in the crank. He just made sure there was no distortion coming UP out of the crank that would wipe the bearing. IMO, a low spot that is small & limited in such a way as to not go to the edge of the support area, shouldnt be a problem, As long as it doesnt create a sloppy fit that allows for motion in a direction other than the direction things are supposed to flex. I would think those little Gurrs could be smoothed up & run. |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 03/10/12 at 08:09:23 687771766B6C5D6D5D65777B30020 wrote:
When you slide the pin in, it feels it binds at that point. I eventually get it in without much effort, but, it seems like it could prevent the pin/rod/piston joint from rotating smoothly, which could cause the piston to not be allowed to travel freely ? I've no experience with this, but, I would think that joint would have to be buttery smooth. |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 03/10/12 at 08:10:25 Does ART make the stock pistons or is that a replacement piston the previous owner put in? |
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Title: Re: Loud knocking, I'm going in... Post by justin_o_guy2 on 03/10/12 at 08:13:07 Feel of it,lay a straight edge on it, hold it up to light & look for anything poking up above what the diameter of the pin is supposed to be.,File it down with a small, fine toothed file, a low spot wont bind or rip anything up. Pushing things together that are rough & dont fit is less than a great idea, |
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Title: Re: Loud knocking, I'm going in... Post by singlesgoinsteady on 03/10/12 at 14:44:17 Just going to get a new piston and rings and slap it back together. |
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