Ignition Timing Question

sts70004

Registered User
I know this isn't an SC quesion, but you guys have been a lot more helpful than the motorcycle forum I'm on, so here we go. This all started after I adjusted the cam chain tension... It was noisy and I didn't have the automatic adjuster, so I set the engine to the proper crankshaft position, and I tightened the chain, and it never really ran right after that. I think that timing is now off. Here's what happens: It can be difficult to start, even with full choke, and once its running, you can't get the revs to climb at all. You crack the throttle slightly, just a slight change in engine sound, not in speed. Full throttle, big change in sound, no change in speed. Could that be from timing being very advanced or retarded?
 
I know this isn't an SC quesion, but you guys have been a lot more helpful than the motorcycle forum I'm on, so here we go. This all started after I adjusted the cam chain tension... It was noisy and I didn't have the automatic adjuster, so I set the engine to the proper crankshaft position, and I tightened the chain, and it never really ran right after that. I think that timing is now off. Here's what happens: It can be difficult to start, even with full choke, and once its running, you can't get the revs to climb at all. You crack the throttle slightly, just a slight change in engine sound, not in speed. Full throttle, big change in sound, no change in speed. Could that be from timing being very advanced or retarded?

Sounds very retarded. Any chance you got the chain off one tooth? That's exactly what it sounds like.
 
I'll take a look. If I figure it out I'll let you guys know. I don't see how I could've gotten it off. The tensioner is something you basically just rotate the completed engine with the timing cover off to the timing mark, then loosen the lock bolt, the plunger moves automatically, then you retighten...
 
Chains stretch. when you tightened the tensioner the slack would have been taken up by something geared to the chain. Did you happen to notice how much slack you took out? Enough for a gear tooth?
 
Well I think I figured it out, i recently removed the air filter because it needed to be replaced and it ran like that before I removed the slack, and I stuffed a towel in the air box to test if it was just running too lean without a filter, and it started up better and would rev. I guess the slack in the cam chain was enough to let the engine run with that air/fuel mix (i was not riding it like that, just been getting some things worked out), and when I took the slack out it tightened it up and it no longer ran. Timing may still be off, but now I'm going for an air filter first. I'll rent a timing light tomorrow.
 
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