Carburetor troubles - your help is required! (please!)

[sa mokin]

Hi Moke gurus

I replaced my old mechanical fuel pump with a new one - and now I can start and run the car - that is until it starts spewing fuel everywhere.

From what I can see - the problem seems to be coming from the float chamber body. When the chamber fills to the top with fuel - the float seems to shut the valve off (I can visually see the pin depress when testing the assembly in a clear glass jar of fuel) - but it obviously isn't because fuel shoots out for every pump of the new fuel pump!

How can I overcome this problem? Does the needle / seat assembly need cleaning/repair/replacing???

Are these HS-2 type carbs easy to rebuild? (Let me quantify that - easy to rebuild by a newbie?)

Any help is appreciated - I am making a mess of my cleaned up engine bay!  :lol:

[tainted]

First question, what type of fuel pump is it?

Some pumps generate high pressure, SU's run on vacuum, air flowing over the jet draw, hopefully, the right amount of fuel for the mixture. Presurised pumps force fuel into the system, if there is no return, not sure of any Mokes with a return fuel system, then the excess fuel has to go somewhere.

[sa mokin]

It is a mechanical pump made by QH and purchased through Minisports - nothing fancy - I dont think it is high performance.

Whatever controls the flow of fuel into the chamber (needle/seat assembly?) isn't working - is this a part that can be replaced/repaired?

[Tim]

You can sometimes get a problem when you re-assemble the carby with the float chamber empty. The float sags down so far that it jams against the end of the needle and stays open. You probably need to replace the float needle and its seat. You want the viton tipped needle with a ball bearing at the other end, if you can get one. The viton (a kind of rubber) seals well and the ball bearing stops it snagging on the arm of the float. Check the float level is ok (assuming you have the type with a metal float arm), and if it still leaks try bending it down slightly.

Tim

[sa mokin]

Thanks Tim

The force at which the fuel shoots out tells me the needle assembly is stuck open - I will clean/replace in the morning and let you know how I get on.

It is exciting in that the car was a non runner when purchased and it was running for a few seconds anyway - tells me I must have the wiring right!
 :lol:

[bnicho]

Sometimes when you change the pump or filter a tiny piece of rubber or similar can make it's way to the needle and seat and jam it open.  It's happened to me twice.

[sa mokin]

Good news - I went over to Minisports and bought a new needle/seat and gasket - and the car now purrs like a kitten!

Thanks to all for your help - I am busily bolting everything back in to go for a joy ride!

 :lol:  :lol:  :lol: