Originally Posted by
Old Fart
Nah don't bother with the vid we've all heard flat engines and wondered why sometimes.If you keep them at full throttle while you make your mind up they go bang sometimes.
It's a good question about the tooth out cam timing thing.Only time i ever came across that was when i mistimed an xr350 honda by one tooth and it behaved as ian says his 150 is doing,just a thought.
Missing the timing on a Saito by one tooth will result in timing being off by 15°. Timing shifts to bump the torque curve via (automotive) custom timing sets are usually limited to + or - 4°.
4° variance in cam timing either way from "straight up" is substantial. 15° Is way to much for the engine to run W/ any resemblance to normality.
The one time I did try to start a Saito that was off by a tooth, it kicked back against the starter, popped & refused to even start. That was W/CDI too.
It's a good thing it wasn't my HC 180 or I fear valves would have gotten way too "familiar" W/the piston.
The point is, being off "by a tooth" on cam timing won't result in a few thousand RPM of lost power or tradition problems, it will result in the engine barely running if it starts @ all.
Advising people to check cam timing in those instances of moderate loss of power will only result in unnecessary dismantling of the valve train.
Of course doing the overlap check @ TDC would verify any cam timing issues (or lack thereof) but many less experience folks might just tear into the valve train W/O the easy check.