23,000 mile valve check - results

[duhs10]

ALL MY VALVES WERE VERY TIGHT AT 24,000 MILES 
REINSTALLING CAMS INDEXED (TIMED) CORRECTLY IS CHALLENGING TO SAY THE LEAST. I HAVE TO GO BACK IN AND CHECK THE CAM TIMING AND BE SURE THE CAM CHAIN IS TIGHT ON THE EXHAUST SIDE. MY APE CCT WILL TAKE CARE OF THE INTAKE SIDE (I DID HAVE THE CCT REPLACED PER THE TSB BUT BASED ON WHAT I'VE READ DO NOT TRUST EVEN THE LATEST OEM CCT). I HAVE A THROTTLE CHOP IDLE DROP ISSUE I'VE POSTED ABOUT ELSEWHERE I BELIEVE IS RELATED TO BEING OFF ONE CAM CHAIN SPROCKET TOOTH ON ONE OR BOTH OF THE CAMS DUE THE DIFFICULTY OF REINSTALLING THE CAMS...
 
ANYONE KNOW WHAT I'M TALKING ABOUT?

@skippert
 
Any help?

[skipperT]

They suck to put back in and get timed correctly. VERY easy to jump a tooth.
 
The running condition could absolutely be caused by being off a tooth. However, I’m not sure this engine will even rotate over completely without hitting valves on pistons if the timing is off a tooth.
 
Could be something else as well. Need more info.
 
-Skip

[koth442]

My Daytona 675, also an interference motor, ran 1 tooth off.

[skipperT]

My Daytona 675, also an interference motor, ran 1 tooth off.

 
That’s interesting! Must have a sweet non-interface spot somewhere in order for that to happen. ?
 
-Skip

[koth442]

My friend who used to be a race engineer on the AMA Factory road racing team said they'd run 1-1.5 teeth advanced sometimes. Typically 1-1.5 teeth isn't enough for a collision. He said 3 teeth is almost guaranteed piston / valve collision. 2 teeth is a maybe, but 1 tooth is typically not an issue. Motor has to be tuned for that change in cam timing though.
 
They achieved 1.5 teeth by machining the mounting hole in the cams a bit.

[2and3cylinders]

If I am off one or more teeth on the intake and or the exhaust cams it's certainly will run without things kissing each other badly. I've checked everything else that I can think of about for the condition I'm experiencing. Specifically, if you Rev the engine and then let go allowing to drop back down it dips below normal idle speed for a split second and then comes back up to standard idle speed.
 
This split-second hiccup when riding can cause a stall at low speeds, it can be ridden around by keeping the revs up but it is annoying to a anal retentive / add / dyslexic like me. And it only began after I adjusted the valves and replaced the cam chain tensioner. I also of course changed the plugs, checked the throttle body sync and adjusted the accelerator position module. I triple checked the CCT, TB sync and AP settings, so it seems the only variable is the cam timing and possible resulting excess slack on the exhaust side of the cam chain.

[skipperT]

If I am off one or more teeth on the intake and or the exhaust cams it's certainly will run without things kissing each other badly. I've checked everything else that I can think of about for the condition I'm experiencing. Specifically, if you Rev the engine and then let go allowing to drop back down it dips below normal idle speed for a split second and then comes back up to standard idle speed. 
This split-second hiccup when riding can cause a stall at low speeds, it can be ridden around by keeping the revs up but it is annoying to a anal retentive / add / dyslexic like me. And it only began after I adjusted the valves and replaced the cam chain tensioner. I also of course changed the plugs, checked the throttle body sync and adjusted the accelerator position module. I triple checked the CCT, TB sync and AP settings, so it seems the only variable is the cam timing and possible resulting excess slack on the exhaust side of the cam chain.

 
You seem fairly confident in that statement, and I would caution that you just never know, especially with today’s high compression ratio engines. I recently had a single cylinder 14 YZ450F apart that had the intake timing 1 tooth off and it bent a valve. YMMV.
 
Sounds like you have narrowed it down pretty well as to what it might be. I would also verify that the APS/TPS numbers are where you think they should be (takes 2 seconds) and I’d also verify sensor and electrical connections of everything you disconnected (some can be mixed up, ie intake air pressure sensor if memory serves).
 
It could also be as simple as the throttle body not being all the way seated in the intake manifolds, or some other kind of intake leak.
 
Good luck,
-S

[gv550]

I just completed a valve clearance check and adjustment on my 9 month old GT,  well before the recommended 42k.

All intake valves were within spec, .14, .16, .16, .16, .15 and .14 mm clearances, spec is .11 to .20 mm.

All 6 exhaust valves were tight, .15, .20, .18, .20, .20, .20 mm clearances, spec is .26 to .30 mm. Swapped one shim and bought 5 new ones to end up with .28 to .30 so should be good to go for a while.

I'll likely check them again in 20,000 kms, sure not comfortable letting them go to 42k.

I combined this job with a chain replacement and steering bearing service, having the front wheel and forks out of the way sure makes this easy.

 

Edited August 11, 2019 by gv550

[piotrek]

50 minutes ago, gv550 said:

I just completed a valve clearance check and adjustment on my 9 month old GT, 30,600 kms which is well before the recommended 42k.

..........

All 6 exhaust valves were tight, .15, .20, .18, .20, .20, .20 mm clearances, spec is .26 to .30 mm. Swapped one shim and bought 5 new ones to end up with .28 to .30 so should be good to go for a while.

I'll likely check them again in 20,000 kms, sure not comfortable letting them go to 42k.

..........

Thanks for posting the data. Same old... that lash check interval for the CP3 is way optimistic.

[tktplz]

If you do your own valve adjs as I do here's a chart to help with valve sizes needed with the clearance you have before the change;

 

file:///C:/Users/TKTPKZ/Documents/Valve%20Adj%20Files/Valve%20adjustment%20calculator.htm

 

Hopefully the link will work........I used it for my ZRX1100 and my ZX11 but it will work with most bikes. I just like that it does the math for you. You put in the intake lower and upper clearance and your measurements of what you have , it tells you the size shim you need.  Same with exhaust.

Edited August 3, 2019 by tktplz

[betoney]

46 minutes ago, tktplz said:

file:///C:/Users/TKTPKZ/Documents/Valve%20Adj%20Files/Valve%20adjustment%20calculator.htm

 

47 minutes ago, tktplz said:

If you do your own valve adjs as I do here's a chart to help with valve sizes needed with the clearance you have before the change;

 

file:///C:/Users/TKTPKZ/Documents/Valve%20Adj%20Files/Valve%20adjustment%20calculator.htm

 

Hopefully the link will work........I used it for my ZRX1100 and my ZX11 but it will work with most bikes. I just like that it does the math for you. You put in the intake lower and upper clearance and your measurements of what you have , it tells you the size shim you need.  Same with exhaust.

That doesn't work as a link, it looks like the file directory location on your hard drive. 

[tktplz]

Yeah, found it in documents, it's a zip file but doesn't end in jpeg. jpe, jpg, etc. it's about 8.5 MBs. 

Edited August 3, 2019 by tktplz