Starting.

[Cal Price]

Oh it's the project bike again. The '81 Yammy.

It's a naked twin like the GS. Battery is OK, I press starter and I can hear the starter whrrrrring and the occasional phut!. Clean and check plugs, OK. Run a few paces and it bump starts sweet as a nut.

Most likely problem ? ? ?

[Roadstergal]

Does the starter actually crank the engine, or just whirr?

[Cal Price]

Metalic Whirrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr and goes on a couple of seconds after I take my thumb off the button.................

[RVertigo]

Starter...  I know little about motos...  But, that problem in the car would be the starter or the charge going to the starter...  You say the battery is ok...  So...  

It may be partially engaging (giving you the occational putt).

But... What do I know.  

[Badger]

If the starter continues to whir after current is cut (and without the engine turning) then it is probably not engaging the whirly bits of the engine.  Compression resistance in the engine should stop the starter from continuing unpowered.  Could be a broken starter, could be an improperly connected starter (not sure how it engages in these engine configurations), but your problem is likely with the starter.  

Considering that the engine actually starts when you push start it, I suspect a faulty starter.  Remove it, check for damage.  If you suspect improper connection, hook it back up and see if it works...consider it a "practice run" for when you get a working starter.

Not that I know much about motorcycles. *shrug*

[Cal Price]

Yeah, this is well weird. Press the button and it will whirrrrr for a couple of seconds after letting go but stops immediatly if you use the kill switch indicating that it is not tuning on its own but engaging the engine.

At first I though that power was getting to starter and not to plugs but bump starting it may rule that out but not 100% it may be that the starter is hogging all the power and insufficient is getting to the plugs. I will have to do some head scratching. This will probably have to wait till Monday as I am working nights over the weekend and my waking hours are just about allocated.

[RVertigo]

It could be the starter gears are toast...

[RedShift]

Troubleshooting remotely like this is tough, but here are my ideas:

• Check that you are getting good contacts all through the starter circuit.  Your battery may be solid, but if the connections are poor, you can't deliver the amps.  Somehow, it still sounds like you're not getting the power where it belongs.
  
  
• Pull the plugs so you have no compression, then try to turn over and see if the starter behaves the same.  If it turns the motor just fine, the motor may well be okay, just not enough power.  Put one plug in and try again.  If lack of compress doesn't matter, I would suspect the starter and look for another.[/list:u]My two cents worth.  Sorry can't be more help.

[Cal Price]

Redshift...

Troubleshooting remotely like this is tough, but here are my ideas:

Thanks, I think you may be onto something there, I will give that a go, probably Monday, I'll let you know or be back in desperation.  :dunno:

[Cal Price]

Well, after my nights, I get up on Monday at lunchtime and decide to have another look, bump it, and she starts fine. Try the starter, IT WORKS!.

Taking my own advice (and Redshift's)before getting too technical look at the obvious, start at the begining ki nda stuff and it was literally the very begining. There was in intermittent fault in the actual switch. Press the button and the rubber outer was coming back but internally it was sticking and just running the starter which I am assuming hogged all the power so not enough to kick the plugs. Emery paper and WD40 solution.
All I need now is to sort out the electrics for the intermittent turn signals! but I think I have got that sussed, and a speedo cable.

Mine is the US model, it has a cover plate, where, on the brit model, there was a kick start. I'm beginning to think one would be very handy!!!

[RVertigo]

Good news.

I bet you can get a kick for it.

[RedShift]

Excellent news.  +1 for working on the simple stuff first.  Nice detective work Cal.

[Cal Price]

I have been looking around the breakers etc, I am told that there were not many 400s about but the mechanism was identical to the 250 and 360 which only had kickstarts. A mechanic tells me that there were a lot of 250s sold in the early 80s so it's just a matter of looking. I would like to find one someday. There is an amazing breakers about 30 miles from here with so much stuff it would take a day or so to sort through it. I managed to find an authentic tank badge there recently, all I need now is a right-hand side one!