350 Carb - float?

[separatist]

Pardon the newbieness of this post, I'm not a carb guy. 350 has been running rich on an Amal carb, but I've just been living with it for lack of time. The other day I rode to a local store, turned off the petcocks and parked. When I restarted I forgot to turn on the gas, so I was running on the gas left in the carb for a bit. What followed was 2-3 minutes of the smoothest, cleanest running I've ever experienced... before I ran out of gas, obviously. Would this indicate that I need to adjust the float rather than adjust the jets?

Like I said, I'm not a carb guy.

[Duccout]

I would guess that you need a smaller pilot jet, or to lower the needle one notch.

[Bevel-Heaven]

you answered your own question.

I have heard more than once at the track " my bike was the fastest it has ever been,......... just before it blew up "

Time to rebuild your carb. See how she goes, then raise the needle clip [lower the needle]. Changing the main jet will only affect full throttle so don;t mess with that until yoiu see how these changes affect things.

[Desmo46]

I would check float and the float level first. Amal float needle seats are a press fit in the bowel and can move over time.

[VintageDuc]

Don't have much experience with Amals so can't speak for them specifically but I did have have similar richness problems with both my 750 Sport and 450 Desmo (Dellorto PHF32 and VHB29 respectively). In both cases it was mostly due to worn needles and atomisers, especially the atomisers which seem to cop the brunt of the wear. With the the 450 I think it was a leaking float valve as well, because I had exactly the same thing as you - turn off the petcocks and it ran beautifully for a few minutes until of of fuel.

Rebuild the carb - especially needle, atomiser and float valve. Viton tipped float valves are great for Dellortos, not sure if that applies to Amal..

[separatist]

Thanks so much folks. I'll pull out my Haynes, see if I can figure out what "lowering the needle a notch" actually means! LOL. I HATE carbs.

[Duccout]

Don't forget to check that you have the correct pilot jet, as it affects more than just the idle. Also, it's possible that the slide has too small a cutaway too.