I knew I could not trust the "B"

[Incubus]

Fricking motorcycle.
Succubus.
Replaced head.
Started.
Ran it around this morning. Ran really good.
Got home. Idling in driveway to drain carbs.
Click. Chingy noise, like a little chain hitting case.
Starter turns. Crank doesn't.
Great.
The Bitch is back.

Patrick

[fredintoon]

- - - Idling in driveway to drain carbs.
Click. Chingy noise, like a little chain hitting case.
Starter turns. Crank doesn't.
Great.
The Bitch is back. - - -

Hi Patrick,
at least the B is an F so it's got a kicker stub to see if it's seized or will still kick start. It could be worse. Try pushing an SG along the road to check those things before you whine too loud.
Does it ching when the starter spins and the engine don't?
Did it ching with the engine running?
Apart from the chinging, I've found my starter just goes whizz and don't engage the engine if the battery is low.
Try boosting with your car battery.
Mind you, having to do a full teardown to get at the starter clutch does sour a person on the wisdom of Yamaha's design team.

[Incubus]

I'm draining the tank now, Fred. My initial diagnosis, which I completely hope is wrong, is the cam chain. Not irreparable, but a genuine pain in the neck as these chains are endless. I haven't found one with a master link, anyway. I am not anxious to tear this engine down completely. I could do a chain with a link, since that would just be pulling the head. Again.

I have lots of valves from junk heads, if anything got bent.

How can two bikes of the same model from the same year be so different? Incubus just runs and runs. Succubus has always been a problem.

Patrick

[MaximPhil]

I'm draining the tank now, Fred. My initial diagnosis, which I completely hope is wrong, is the cam chain. Not irreparable, but a genuine pain in the neck as these chains are endless. I haven't found one with a master link, anyway. I am not anxious to tear this engine down completely. I could do a chain with a link, since that would just be pulling the head. Again.

I have lots of valves from junk heads, if anything got bent.

How can two bikes of the same model from the same year be so different? Incubus just runs and runs. Succubus has always been a problem.

Patrick

Hi Patrick,
Camchain with master link is available from Parts & More.
Phil

[fredintoon]

Hi Patrick,
um, first you say there was a ching sound and the starter spins but don't engage.
Then you reckon the timing chain has slipped.
I'm with you; WTF?
I'd suggest pull the plugs, put the tranny in neutral, remove the top & leftside covers and slowly and carefully turn the motor over with a wrench on the crankshaft nut.
Feel & listen for a resistance to being turned that may indicate a valve hitting a piston.
If you can get a linked timing chain like Phil sez, cut the in-place endless chain with a Dremel tool, wire the new one onto the cut one and wind it through.

[Incubus]

I am pretty certain that is what happened. The engine does not move forward, either with the kickstarter or the timing wheel. I didn't force it much since I don't want to put a valve through a piston.

I think, for a while, I am going to ride Incubus and let Succubus go back into hibernation.

Patrick