Vm33 smoothbores

[blowerbike]

They are Mikuni boots, there are no o-rings. It just mates to the intake manifold.

I will switch 3 & 4 intakes and see if the problem follows.

Thanks,
Daryl

check for leaks.
i always silicone those type of boots.

[Fjbj40]

check for leaks.
i always silicone those type of boots.

I siliconed when I installed them. Will pull and check for cracks and reinstall if none found.

Stay tuned

Thanks,
Daryl

[Fjbj40]

I pulled all boots, checked them and no cracks or leaks. Reinstalled them with permatex and swapped 3 & 4.

No change!

Screwed pilot airscrew in tight and that seemed to improve it a little. Cranked the idle up to 3500 rpm and started whacking the carb bowl with screwdriver handle and it hiccuped and speed changed a little.

Shut her down and did a compression test with carbs removed. 1 to 4 are 160, 160, 125, 160. So I suspect it is a mechanical issue and not carb related.

Fawk

[Fjbj40]

Problem solved

It turns out that the vent on #3 is not a vent. It is the vacuum source for the fuel petcock.

Soon as I plugged it she purred, and when you crack it it breathes fire
This is going to be a monster.

[blowerbike]

yeah major vacuum leak on the dead cylinder.
makes sense.
at least your carbs are in sinc now

[Fjbj40]

yeah major vacuum leak on the dead cylinder.
makes sense.
at least your carbs are in sinc now

Yes, major leak. Thank you sir for the help, I learned what a bench sync is

Daryl

[ozman]

show us a picture of your carbs

ozman

[Fjbj40]

You can see the vacuum hose from 3 here. It is not a vent