Carb Rebuilding

[sped372]

In the process of rebuilding a 34-3 that I could never seem to tune completely. It's a Solex, not a Bocar but I couldn't get the idle slow enough and it always ran rich (I could smell it and it would flood on a hot re-start).

Anway, the main question is, will a good scrubbing and blasting of Gumout through all the ports be sufficient? I don't have access to compressed air or an ultrasonic cleaner or anything like that.

I have removed all the jets, plugs, etc and gotten everything as clean as I can but I still worry about little pieces of crud down in the internal crannies.

The o rings on the adjustment screws were shot so I'm hopeful that was a majority of the tuning issue... but I'm conflicted on whether it's clean enough to put back together (with rebuild kit, new gaskets etc. obviously.)

I see three options...

1. Put it back together.
2. Find a shop or someone with an ultrasonic cleaner, then put it back together.
3. Send it to keifernet.

No big deal either of the three ways, just would prefer to get it done in one shot.

[bajaman72]

Use the nozzle (WITH GOGGLES) of the carb cleaner to get in the nooks and crannies. Should be ok.

[Sluggo]

Use the nozzle (WITH GOGGLES) of the carb cleaner to get in the nooks and crannies. Should be ok.

Definitely with goggles. I found out the hard way. You'll hit a groove the right (wrong) way and the gumout will make a direct hit in your eye.

[Sylvester]

Use the nozzle (WITH GOGGLES) of the carb cleaner to get in the nooks and crannies. Should be ok.

Definitely with goggles. I found out the hard way. You'll hit a groove the right (wrong) way and the gumout will make a direct hit in your eye.

I got lucky then when I rebuilt mine last month. None in the eyes.

[Amskeptic]

In the process of rebuilding a 34-3 that I could never seem to tune completely. It's a Solex, not a Bocar but I couldn't get the idle slow enough and it always ran rich (I could smell it and it would flood on a hot re-start).

Anway, the main question is, will a good scrubbing and blasting of Gumout through all the ports be sufficient?

Yes. Too rich symptoms are a good indication that you do not have clogged drillings.

Check float level and all jet numbers. Make sure throttle plate is operating correctly. Fast idle screw at top of throttle lever *is not supposed to touch cam* when choke is open, unlike earlier carburetors that used this very screw to adjust idle speed. Sometimes, you will have a 1971 34 Pict3 that will want a vacuum retard distributor (like all 1971 air-cooled Volkswagens CAME WITH) to get that perfect 850-950 idle rpm.
Colin

[MeyerII]

What is the best reference for rebuilding carbs? I've never done it before and was going to get around to it pretty soon.

[Amskeptic]

What is the best reference for rebuilding carbs? I've never done it before and was going to get around to it pretty soon.

Early Bentleys are pretty conversational and thorough with explanations of how to set float level, adjust accelerator pump output, and set throttle plates and fast-idle links on bus PDSIT carbs, but, they also get sort of stupid with emissions mixture adjustments.

Carburetors are mostly passive devices. They react to airflow. As such, they are supremely simple to diasassemble and clean and reassemble. Just get a nice clean surface to lay out the parts sequentially as you remove them.

There is only one mystery in a carb. As you shoot all the little holes with spray GumOut with red straw, you must make sure there is a rattle in the carb body as you shake it. This is the accelerator pump check ball. No rattle? Hit the accelerator pump intake inside the float chamber with GumOut and the outlet brass projection on the top surface. Shake it some more.
Must rattle.
Reassemble with care and cleanliness. Only tip I have, other than to make sure the gaskets are correctly indexed, is to use a light coat of grease on mixture and bypass screw sealing grommets. Otherwise, mixture adjustments are going to be a PIA.
Colin

[MeyerII]

Thanks Colin. I'll pull the Bentely out and see what it has to say.