Zenith 40 TIN Accel Pump Help

[kennyt]

I seem to have the same problem with mine , also recently been rebuilt by "porsche specialist " Left bank has no fuel pumped into the chamber when opening the throttle , checked float chamber has fuel in it (will need to check the levels next I guess )
right hand bank squirts fine (I can only see into the first two venturies with the carbs in place )
What are the chances I have the check valves for the air correction jets swapped around too ?
I am a bit reluctant to pull them apart as I paid good money to have the engine completely overhauled (including a carb kit )
I will be calling him to see if he is prepared to check it out but , I guess considering it was done a year ago , I am not holding my breath (the joys of a project car standing for long periods of time as time and money dictate the rate of completion )
Is this a job the average DIYer could contemplate ? ( I guess I am a bit more competent than the average DIY guy - happy to overhaul a 2 stroke , change cam belts etc ) but I am scared I damage the gaskets or don't have the proper tools to do the job ?
Anything I should know ?

[VFR750]

Stoddard sells the little vials. Plastic one was $20. Glass was $90. Went with plastic one. Could use a longer wire handle.

[VFR750]

No special tools for the zeniths. They are quite easy to break down and rebuild. But as we have seen here, there are a lot of parts and you have to keep them organIzed. I used storage tray with lots of little compartments like a fishing tackle box.

If the jets dont work, you have to fix them. No real choice but to dive in. If you are careful you can pull the top off without damaging the gasket

[kennyt]

I pulled the TIN 40s off and found a couple of gremlins

1st there was some powder coating paint on the inside of the manifolds which was peeling off (legacy of another saga ) . I cleaned this up with a mini sanding dremel wheel.

I found that only one of the accelerator pump nozzles was not squirting (the front one that you can see with the carbs installed ) so I dismantled the left bank of carbs, The offending nozzle was blocked and came clean with some carb cleaner (thank goodness )

I then noticed that there appear to be 3 jets looking from the top but four places for jets ? one missing ? the others have SOLEX 785 on them ?
Are these the Air Correction Jets from the previous link ?
On the Motor Meister site it show 3 in the picture but lists 6 ? is this 3 per carb ?
Cheers Kenny

[1QuickS]

Carbs have same casting but are machined to be right and left hand versions. The carb suppies three cylinders but has two float bowls so fuel for fuel delivery for two cylinders comes from one float bowl while fuel for main delivery plus accelerator circuit comes from the other well. What you see from the top view is the air correctors for the main circuit from the right hand fuel well and the singular air corrector for the main circuit in the other well plus the un-machined bore for the air corrector which isn't used.

[Einar Irgens]

I have another question regarding the acceleration pump. On idle I noticed that fuel seeps out of the accelerator pump nozzle and into the intake. What could be the reason? I think there is a glass ball inside the nozzle unit, but is this to prevent fuel from running back into the float bowl?

(later this year this thread has a ten year anniversary ;-)

Einar

[VFR750]

The only time this happened to me was when the screws holding the floats backed out and let the float fall into the well. That allowed the float chamber to completely fill up and the accel jet was the first place the excess fuel would go.

Unfortunately this happened a few times until I got the screws tight enough.