[cyrusb]

Have you actually checked for spark when this is happening? Wet plug,etc? One easy check can go a long way.

[High On Octane]

Have you actually checked for spark when this is happening? Wet plug,etc? One easy check can go a long way.

+1 Have you done any actual diagnostics yet?

[sherman_desouza]

+1 Have you done any actual diagnostics yet?

checked all wiring, checked for spark, checked for fuel flow, checked battery voltage, checked timing.
the bike runs fine and this has only happened when it is very hot outside.

i took her for a long ride yesterday in about 20 C ambient temp and no issues whatsoever. this is really bizarre.

[sherman_desouza]

Have you actually checked for spark when this is happening? Wet plug,etc? One easy check can go a long way.

yeah i have a nice spark. plug was a bit sooty so might be running a bit rich...

[cyrusb]

O.K, so it has good ignition during the episode. Plug is sooty, but is it wet? Repeated kicks with no starting should leave the plug wet with unburnt fuel. If this is the case you have a lean condition. Is there a MICARB involved here?

[sherman_desouza]

O.K, so it has good ignition during the episode. Plug is sooty, but is it wet? Repeated kicks with no starting should leave the plug wet with unburnt fuel. If this is the case you have a lean condition. Is there a MICARB involved here?

during the episode it would fire if i left it alone for a couple mins but would quickly die as soon as i opened the throttle, and then wouldnt start again till i left her alone for a bit

plug was not wet when i got back home. just sooty.

and yes, its a micarb VM28 with the jets specified by Hitchcock's.

[cyrusb]

It's the carb. What happens next is up to you. I tossed mine in the trash and bought a pwk 30 and have never looked back. You could keep fiddling with jetting etc, but I just bought a better carb (and a cheap one at that). 10000 trouble free miles.

[sherman_desouza]

It's the carb. What happens next is up to you. I tossed mine in the trash and bought a pwk 30 and have never looked back. You could keep fiddling with jetting etc, but I just bought a better carb (and a cheap one at that). 10000 trouble free miles.

yeah it could be the carb because the electrical system looks like it is in good shape.
I was leaning towards the mikuni TM32 anyways so maybe next riding season I will change it to that.

[cyrusb]

One last data point, how is compression during the "no start when hot episode?" A hung up exhaust valve would give a dry plug after many kicks because the cylinder would be breathing through it and not the carb. This would not be  obvious if starting with the comp release as you are never against the compression stroke.

[sherman_desouza]

One last data point, how is compression during the "no start when hot episode?" A hung up exhaust valve would give a dry plug after many kicks because the cylinder would be breathing through it and not the carb. This would not be  obvious if starting with the comp release as you are never against the compression stroke.

Compression is fine and actually very good.

[banjelele]

ERC mentioned the valves. Fortunately that is such an easy thing to check. One bolt and you can remove that little adjustment plate. Give those suckers a spin. If one is too tight it can even be adjusted hot with the pair of wrenches that came with the bike. No need to even burn your fingers. Ask me how I know.