Jetting? The infamous stutter?

[MikeScoot]

 
   It seems I had/have a t least a couple of issues with the carburetion.

  * The non-venting cap. It now vents. I drilled it, gave it a nipple and attached a moto-crosser type breather line.
  * Very small amounts of unknown thick, sticky transparent liquid were hiding in rear carb body passages - notably                     
     affecting main circuit and pilot function. Hopefully all are now removed.

   All in all a pretty good day 'cos it was great to have the motor running the way it should - even though it now seems to flood easily and needs a rest before restarting. Will recheck fuel pump and regulator as function may be inconsistent.
   Will also carefully check float valve function again in case pressurised fuel is sneaking through.

    Oh? Is that the time? Beer o'clock! Yay!

 

[MikeScoot]

  After cleaning out both carbs again (no crap found this time) and carefully checking all innards of the fuel pump and fuel regulator, the motor ran fine for quite a while and then slowly died and couldn't be restarted until it had cooled.

The good news is that I have a new suspect! The vacuum line from the manifold to the fuel pump. I think that perhaps the line was not sturdy enough and may have been collapsing when it became hot. Didn't test to see because the carbs were off the bike when that suspicion occurred to me. Have replaced that line with a much sturdier one. Also took the opportunity to buy caps for the YICS nipples instead of the line I had connecting the two, which was interfering very slightly with the throttle sync. rod. and very difficult to route due to its sturdiness.

Will test tomorrow after work.

[Rikugun]

When it died did you think to drain the carbs to see what if anything came out? If the carbs had fuel in them, it may be ignition as the symptoms support that theory - runs OK cold and fails when hot. Then again, if this is a new symptom that just appeared after touching the pump and regulator......

[MikeScoot]

Yes, it IS quite possibly the ignition.
Ran quite well for a good fifteen minutes this morning, then died off again. This time it restarted almost immediately without too much difficulty. Went through this a couple of times.
I have been running it with transparent bleed lines so that I can constantly check float level - but not today. Drats!

I did notice that it does seem to die in bot pots at pretty much the same time. So yes, it could indicate an ignitor problem.

Next will be a more thorough check of the petcock and if that looks good then things will be pointing more toward the ignitor. Has anyone ever had one apart? I had a quick look the other day and it seemed to be flooded in with resin.

Cheers

[The Prophet of Doom]

Don't want to sound like a broken parrot, but check your carb sync else you are chasing your tail.

[MikeScoot]

Been done. No considerable difference.