SuzukiSavage.com - I hear you knockin'

verslagen1

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I hear you knockin'
12/02/08 at 09:05:10

Follow up on the '88 with a knock
I thought y'all might learn sumptin' as I do.

The knock sounds like a heavy valves out of adjustment, not the usual tic but a toc.
The PO said got it a few months ago, was riding down the freeway when it lost power and started knocking.
Suspecting the cam chain tensioner, I whipped off the clutch cover to find at my dismay, the tensioner still intact, extended a good amount so I put in a slavy.
Couple of things I noticed while in there, gasket looked pretty new and the oil looked like fried dino guts. So I put in fresh cheap rotella expecting to change it again soon.
So I slapped it back together, adjusted the valves and started her up.
No improvement, still knocks.
Well last weekend, got around to looking at it again, readjusted the valves, Hmmm... all of them are too tight.
One suggestion was to push down on the piston just as it starts down after TDC, tried it and felt no lag in the motion as it moved from going up to down. And no motion when pushed either.

What to look at next?

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Bear_Rider Senior Member Offline Posts: 289	Re: I hear you knockin' Reply #1 - 12/02/08 at 16:59:52 This might be a stretch, but could this twenty-year old bike have enough deposits in the combustion chamber and on the piston to raise the compression ratio enough to cause the knock?
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verslagen1 YaBB Moderator ModSquad Offline Where there's a will, I want to be in it. Posts: 28760 L.A. California Gender:	Re: I hear you knockin' Reply #2 - 12/02/08 at 23:52:16 My suspicions lie in the sluggy oil. Savage greg is the only one I know that dropped a ring after some work. But a bad ring might burn up the oil a bit. I'm also concerned with the change in valve adjustment, could be something loose up there.
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justin_o_guy2

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What happened?

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Re: I hear you knockin'
Reply #3 - 12/03/08 at 02:38:07

As for the oil, you are already on that, a few quick changes & get the crappy stuff flushed out. That parts easy.
About that knock. I dont see how this would help find it, but I would do it just for giggles. I would hook up an inductive trigger timing light & see at what part of the cycle does the knock happen. If its not at the same time as the light flashes, then the piston isnt at compression or exhaust. So, If you knew that, what would you knw? Hekk, I dunno..

The test you did, pushing down on the piston after it started back down. That might work out, IF the slack in the bearings was so loose that the friction of the rings would pull it up, but if the bearing is just "Less than healthy", thers no guarantee that the slack in it would be revealed by the friction of the rings in the cylinder.( IMO, I may be off by miles here)

If you pull the timing cover & just crank it over with a wrench or ratchet, whatever, can you feel the knock? If you pull the plug & hit the starter, can you hear it? What about pulling the plugwire & pulling the decomp cable to engage the decomp & hit the starter with the plug in?

I've heard of guys dropping rice down the intake of a car that they thought might be carboned up. Sure would be a lousy deal to get more in than it could swallow & wind up having to pilaff the head to get the glue out.

If you think ther might be a busted ring in the mix, maybe a borescope to see the cylinder walls is in order? I think they are expensive, maybe its possible to rent one.
I have a magnetic oil drain plug, but havent done the whole
Old Feller magnetic treatment to the oil pathway. I do run a pretty stout magnet thru the oil I drain out. If you think there is metal floating around, maybe pulling the clutch cover again & cleaning & checking with a magnet would be an idea?
Would a compression check do you any good at all? Unless its low, I dont see how it would do you much good. It could be fine & you still have a busted ring, right?

Good luck, I wish I could have been more help

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SV og LS Full Member Offline Kawasaki ZZR 1200 Posts: 236	Re: I hear you knockin' Reply #4 - 12/03/08 at 02:55:52 Many knocking Savages I've heard of have had worn rocker arms and/or camshaft. Pull the valve cover and take a look, you'll remove it anyway if you need to go further.
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PipJones Full Member Offline Posts: 146 Fort Worth, Tx Gender:	Re: I hear you knockin' Reply #5 - 12/03/08 at 06:33:52 what is the compression of the cylinder? psi? Pip Jones
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verslagen1 YaBB Moderator ModSquad Offline Where there's a will, I want to be in it. Posts: 28760 L.A. California Gender:	Re: I hear you knockin' Reply #6 - 12/27/08 at 14:40:03 PipJones wrote on 12/03/08 at 06:33:52: what is the compression of the cylinder? psi? Pip Jones 105 dry / 110 with a squirt of oil. borescope: http://www.tooldesk.com/shop/borescope1.wml
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Serowbot YaBB Moderator ModSquad Offline OK.... so what's the speed of dark? Posts: 28375 Tucson Az Gender:	Re: I hear you knockin' Reply #7 - 12/27/08 at 15:28:51 This may sound stupid, but a friend of mine had a V-Star that swallowed some gunk,...plugged up a jet, and was chuffing along with a way cranked idle mix,...it was stumbly running and making a bad kinda' rod knock sound..... We rebiuld the carbs and it was perfect. Not likely, but.... Hows the idle sound?
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verslagen1 YaBB Moderator ModSquad Offline Where there's a will, I want to be in it. Posts: 28760 L.A. California Gender:	Re: I hear you knockin' Reply #8 - 12/27/08 at 16:58:01 ThumpaKnock, ThumpaKnock, ThumpaKnock... Did run it around the block a couple of times, couldn't say it was hot, but warm def. There's a couple times when the knock would diminish to a tick.
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Serowbot YaBB Moderator ModSquad Offline OK.... so what's the speed of dark? Posts: 28375 Tucson Az Gender:	Re: I hear you knockin' Reply #9 - 12/28/08 at 01:37:51 Just to toss a couple ideas out... adding choke help anything?...might clue you to a carb problem..... or....do you think adding some motor honey, or swapping to a straight 30 or 40 wt, might tell you if it's in the top end or the bottom?.....
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dasch Serious Thumper Offline SuzukiSavage.com Rocks! Posts: 1137	Re: I hear you knockin' Reply #10 - 12/28/08 at 08:25:13 Piston rod bearings?? Main crankshaft/journal bearings (or whatever you call them in English)?? Pain in the a$$. I had a strange knock once when my exhaust manifold got just a bit loose at the head. I torqued it and it stopped, couldn't even tell it was loose by grab and shake method.
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smokin_blue Serious Thumper Offline From Cafes to Streetfighters! I build them all! Posts: 830 St. Paul, MN Gender:	Re: I hear you knockin' Reply #11 - 12/28/08 at 08:27:24 Bad rod bearing?? old Suzuki LT230 quads were notorious for taking out the rod bearings when used and abused. They would knock both at idle and on the gas.
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verslagen1 YaBB Moderator ModSquad Offline Where there's a will, I want to be in it. Posts: 28760 L.A. California Gender:	Re: I hear you knockin' Reply #12 - 12/28/08 at 08:34:51 I rotated the crank by hand alot and it felt smooth. Stuck a screwdriver to the top of the piston and worked the crank back and forth and felt no slop.
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dasch Serious Thumper Offline SuzukiSavage.com Rocks! Posts: 1137	Re: I hear you knockin' Reply #13 - 12/28/08 at 10:07:31 Is this the first time you actually see it running?
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verslagen1 YaBB Moderator ModSquad Offline Where there's a will, I want to be in it. Posts: 28760 L.A. California Gender:	Re: I hear you knockin' Reply #14 - 12/28/08 at 11:50:58 I've ran it only a couple of times, about 10 to 20 min's each. Interesting point, turning the engine backwards does engage the starter as we all should know, but I also hear a kind of chain scrapping noise on the case, same area.
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Question: What do you think is knockin'
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Rod-not 9 (39.1%) crank-not 2 (8.6%) cam-not 1 (4.3%) piston is burnt 9 (39.1%) knee's-not 2 (8.6%) Total votes: 23 « Last Modified by: verslagen1 on: 01/06/09 at 22:58:18 »