Float level 29mm Smoothbore

[colin9623]

Can anyone tell me the correct float height for VM 29mm smoothbore carbs and any info on jet sizes, I have just bought these :-D they have 120 mains and 20 pilot jet. Stock engine with a Mac 4 into 1
Thanks, Colin

[SqDancerLynn1]

I would guess the same 24mm float level as the VM26s.
look for jetting http://www.sudco.com/ look under carb diagrams, VM29

[doctorgonzo]

Ok, BS34 not VM's but....

Rather than start a new thread I bumped this one. I did a dip on my carbs and got them back on a couple days ago. After installing again, #2 is very lean on all circuits, bright white plug. I does run on that cylinder, and pretty well at some throttle positions, but has an intermittent stumble, mostly at about 1/4 throttle. I realized in my haste I hadn't checked the float heights so I pulled them again last night (argh!) to check the float heights and on every cylinder except #2 (which was a new float, explaing the variation from the other three) they were actually too low by a fair bit, #2 was too high. I adjusted them all to spec. My question is I have been fighting a rich condition (until the problem popped up on #2. Could the float level being too low (thus higher level of fuel in the bowl) on the other three contribute to it being rich? I'm going to get them back on tonight, just wondering how much effect float level can have beyond starvation (as I am seeing on #2.

[ryonker]

This is a good question. I am rich on 2 & 3 and not totally sure why. I am putting new points and condensors on today and will check things out again after this. As far as the VM 26's being 24 mm, 24mm from where to where?

Thanks!

Rick

[doctorgonzo]

This is a good question. I am rich on 2 & 3 and not totally sure why. I am putting new points and condensors on today and will check things out again after this. As far as the VM 26's being 24 mm, 24mm from where to where?

Thanks!

Rick

Anytime 2 & 3 or 1 & 4 act the same you always have to sonsider ignition sysem for sure. Doesn't mean it's the case by any means, but always a hmmmmmmm.......

[ryonker]

Thanks!

One of the points was REALLY BAD; Black and pitted. I don't know if it was the one connected to the coil firing 2 & 3 but that is my guess.

[doctorgonzo]

Anybody..... carb experts....
What's the chapter and verse on the effects of incorrect float levels. I know it can cause starvation, but can it also cause a rich condition?

[hampshirehog]

Incorrect float levels can give you weak AND rich problems on Mikunis and similar style carbs. However, you will notice running weak if they are a bit out but you won't notice rich unless they are a fair bit out. (Does that make sense). Usually to go too rich so that you would notice, the carbs would be overflowing, or at least leaking through the bowl / body joint.

The exception to this is on something like a Jikov (eastern bloc) or say an Amal 29 (ancient British) where the float bowl is on the side of the carb - here if your level is too high you'll run rich and notice it. Though I suppose it's all relative

[doctorgonzo]

Thanks, that's what I was looking for.

[SqDancerLynn1]

Any kind of vacuum leak could cause it to run lean #2. Carb boots, loose boot clamp, vacuum line for petcock
Float level can cause all kinds of problems

[doctorgonzo]

Any kind of vacuum leak could cause it to run lean #2. Carb boots, loose boot clamp, vacuum line for petcock
Float level can cause all kinds of problems

Gonna reinstall tonight and all those will be checked.