Cam Timing

[racerrad8]

Thanks for the suggestions, but I still have the same problem. 

Ribbert
        When you start the process you must rotate the crankshaft at least one revolution while holding upward on the cam chain before stopping at TDC. You cannot allow any slack to be allowed during the installation of both cams. Again, after doing this installation thousands of times, you are dropping the chain on the back or intake side. It is falling off of the crank and when you pull it back up it then makes the cam off a "half tooth". The half tooth theory is based on the camshaft rotating at half the crankshaft rotation. Chris' recommendation of having the rear chain guide held against the chain should hold the chain against the crank gear, should help, but ultimately you cannot allow the chain to slack and fall down. And lastly, when you do get everything installed, you should turn the cam (not the crank) in a reverse rotation, which will keep the slack on the slack side of the chain allowing the tensioner to adjust.

Slotted cam gears can help with the install, but they are best suited for the tuning of cam timing. You are correct the engine will go back together without the slotted cam gears, thus the slotted cam gears are not the answer.

This motor has been apart very early in its life (can't imagine why) it has workshop job no. etched onto the major bits (crankcase halves, barrels etc.)  If undue force was applied while assembling could the cam chain have been stretched and would it have this effect?

Do not presume that the engine has been apart by the scribing on the engine. All of the original engines that I have taken apart have scribing on the cylinder head surface and barrels from the factory. The cases used to be scribed for bearing sizing, but now they are punched.

I have never seen a chain tensioned to allow this much stretch; I believe if it was stretched that far, it would have broken long ago. Plus if it was stretched that far, the exhaust cam would not come into time either.

The camshaft installation is the most difficult part of the engine assembly process.

Randy - RPM

[smokamoto]

[/The camshaft installation is the most difficult part of the engine assembly process. Randy - RPM]

No kidding Randy!
I did my cams last night and it was ah, challenging.  Took 2 tries to get the exhaust right, then 2 tries for the intake, leaving the cam chain tensioner mounted & set at the same spot it was when dis-assembled (no springs in it).  Thought I had it, rotated the crank one revolution and NOT, both cams were one tooth retarded.  Marked the chain & sprockets with chalk, unbolted the cam caps & reset the cams, then it was right. 
When I started this project to replace the leaking oil galley o-ring seal at the head gasket, I checked the cam timing before pulling the cams.  The exhaust was one tooth retarded (thanks to previous owner)!!  And now that it's right, it runs much smoother at 1/8 throttle in the lower gears, no more hubbabubba.  Or maybe it was the 40 pilot & 145 air jets, the spin-on oil filter, the 17" YZF-600 rear wheel, the Michelin Pilot Road tires, or the new chain & sprockets !

[racerman_27410]

I'm to understand that you found the missing kookaloo?

good! we cant have unattended Kookaloo just waundering around 


KOokaloo!


Frank

[Dan Filetti]

The exhaust was one tooth retarded (thanks to previous owner)!!  And now that it's right, it runs much smoother at 1/8 throttle in the lower gears, no more hubbabubba.  Or maybe it was the 40 pilot & 145 air jets, the spin-on oil filter, the 17" YZF-600 rear wheel, the Michelin Pilot Road tires, or the new chain & sprockets.

I'm guessing the new found smoothness was due largely to the spiffy new spin on oil filter.