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-   -   Pullled my head off, I need some advice (http://forums.sv650.org/showthread.php?t=126936)

HighRisk 04-03-09 04:42 PM

Pullled my head off, I need some advice
 
So I bought a 2001 sv650 and the guy told me it had a bad valve seat. He said he was driving it and it backfired and then started to make a ticking noise from the rear head. I never heard it run or anything so I am just going off that. I took the head off today and from what I can tell it looks fine. But I looked at the motor and it seemed like there was a gap between the piston and the cylinder wall. I was wondering if that was normal or not, or maybe its just a gap only on the top of the piston but not the rest of it. What should my next step be? Here's some pictures so you all can see whats going on. Thanks
http://i163.photobucket.com/albums/t...0/100_1386.jpg

http://i163.photobucket.com/albums/t...0/100_1387.jpghttp://i163.photobucket.com/albums/t...0/100_1388.jpghttp://i163.photobucket.com/albums/t...0/100_1389.jpghttp://i163.photobucket.com/albums/t...0/100_1383.jpghttp://i163.photobucket.com/albums/t...0/100_1384.jpghttp://i163.photobucket.com/albums/t...0/100_1385.jpg

shifter 04-03-09 04:49 PM

Re: Pullled my head off, I need some advice
 
Looks o.k to me. The gap around the piston is normal, that's what piston rings are for. As for the noise I'd have started by checking the valve clearances.
If not could possibly be a little end.

HighRisk 04-03-09 04:53 PM

Re: Pullled my head off, I need some advice
 
Alright wonderful. How could I tell if the head has any problems? I don't have the tools to take the valves out. Is there anything visual I could see, or is there something else that could be making the noise, btw the cam chain tensioner seems to be working correctly the cam chain was taut.

shifter 04-03-09 05:01 PM

Re: Pullled my head off, I need some advice
 
The only visuals I can think off checking are damage to the piston crown (can't see any in the photo) and pushing the piston down to the bottom of it's stroke. Then you can check the barrel for scoring.
I'm only guessing but if you press your fingers against the piston crown and rock the engine back and forth gently with a spanner on the crank shaft, you may be able to detect any play in the little end.

yorkie_chris 04-03-09 07:40 PM

Re: Pullled my head off, I need some advice
 
Would have been better to compression test it first.

Those marks on the piston aren't valve marks, but they could be the result of detonation.

flymo 04-03-09 08:33 PM

Re: Pullled my head off, I need some advice
 
Quote:

Originally Posted by yorkie_chris (Post 1808644)
Would have been better to compression test it first.

+1 Could have elliminated rings and valves and saved the cost of a set of head gaskets.

Ticking noise may well be a dodgy cam chain tensioner or incorrect valve clearance. Trouble is its hard to check now that its apart.

yorkie_chris 04-03-09 08:34 PM

Re: Pullled my head off, I need some advice
 
You can check valve clearances by bolting cams back in, should be accurate enough.

HighRisk 04-03-09 08:56 PM

Re: Pullled my head off, I need some advice
 
Thanks for the help guys. I feel like an idiot not checking the clearance first just when I bought it the guy was surreeeee it was a valve seat, since I've been reading about stuff I can see that he was wrong about a lot of things he told me. But anyway what do I need to check valve clearances, a thickness gauge?

yorkie_chris 04-03-09 09:21 PM

Re: Pullled my head off, I need some advice
 
Yes, also a torque wrench to put the cams back (10nm)

HighRisk 04-03-09 09:35 PM

Re: Pullled my head off, I need some advice
 
Yes I've already bought a torque wrench today :) I've got another question. If I put the head back on and want to put on the cam chain tensioner, can I just use a screwdriver to hold the tensioner closed until i put the cams and cam chain in and then pull out the screwdriver to open the tensioner? Because that would save me $50 Also how do you tell if the cam chain tensioner is working properly? It sprung out when I was playing with it but it wasn't wicked fast like I thought it was gonna.


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