F80 Backfiring and Shaking at Idle

[almetelo]

Hi!

If you you're "sure" your carb is properly cleaned then you need a downleak and a spark test...

Hope problem still on carb

[mattro51]

I thought about taking off 1 and 2 and switching positions. If the problem jumps to cylinder 1 it must be the carb I would think. Would there be any problem in switching carbs to a different cylinder?

[rodbolt17]

your doing your own work, clueless as to how it works?

good luck with that.

BTW that emulsion tube has nothing to do with low speed operation.

remember the passages are very very small, especially on the low speed circuits.

clean them properly and the issue will go away.

and YOU MUST use a 4 channel manometer to CORRECTLY set the shutters on reassembly.

NO other way around that FACT.

[mattro51]

I've got a manometer and am following the service manual to the letter on carb sync and adjustment. Looks like I'm going to take it off again and soak it. Lets hope that fixes my carb problem. Thanks for everyone's input.

[99yam40]

is it a 4 channel manometer like manual calls for?

Need to look at all parts in the carbs in part break down , some carbs have different jets and maybe other things.
If they(carbs) are listed with different part #s there is something different

[mattro51]

Yes I do have a 4 channel manometer. Thanks.