A/C B model carb problem?????

Raptor44

Member
Finished my B and it starts and idles fine. Problem is if I open the choke more than a 25% it will start running bad and then stall. It will run fine but even pulled my mower out of the pond with it yesterday. Got to close. Have had this carb (marvel) on and off, apart rechecked everything. Any ideas. Help Please
 
Is it one of those carb with the plug over the main jet so no way to adjust the main?? If yes pull the plug and turn the gas on and make sure you get a good steady flow of gas out of it. If you do not the main jet is part way plugged and you need to use a piece of wire or as I do a torch tip cleaner tool and poke it out real good then let gas flow and maybe do that a few time. I have had to do that a number of times over the years on the carb on my C
 
Before you take anything apart take the cap
off the air cleaner and start the tractor
and while running wide open cover the stack
with your hand for a second and let it
recover. Don't kill the engine, do this 3-4
times. Some times this will suck the clog
out of the jet.
 
A little background. This carb is a TSX 154 a type A with a fixed jet according to the PDF on the internet. It has been cleaned quite good. Rebuilt with a high end kit. It was initially flooding. Solved the flooding issue by ditching the replacement needle valve and clip and reinstalling the original needle valve. Float adjustment is spot on. Confirmed all passages in carb are clear. Have put my hand over air filter as suggested, have checked for vacuum leaks at carb and intake. Head has new springs and valves and two new seats all others have been ground. No water leaks etc. It runs the same way even with the air cleaner removed.
 
Have you removed the main jet cover plug and done what I said and made sure you have a good steady flow of gas out of it?? Only takes a small piece of dirt/rust to clog the main up and will cause that type of problems
 
there is no cover plug. Just a new main jet which I have removed blew it out again and reinstalled. Doing same thing. Wonder if its junk. Will tear it down again and then re post. Thanks
 
Do you poke out all the carb passageways with a piece of wire or as I do I use a torch tip cleaner tool to poke them out then spray carb cleaner into them and poke them out a 2nd time. I have found that is you do not poke the passageways out you cannot get all the dirt/rust etc out and you WILL have problems
 
I will tear it down tomorrow again and go through it. This will be the fourth time. Today I'm working on my 32 ford.
 
My brother had a carb on a WC that acted like that. Turned out there was a passage from before the choke butterfly to the bowl, a vent. It was plugged by a mud wasp and
you couldn't see it with a quick look in the intake of the carb. Took the mun out and cleaned the passage and it was fine.
 
It could be a passageway in the carb that's still plugged. you can use a propane torch to melt the stuff plugging any passageways. Then blow thru. Have you removed the nipple which brings fuel into the carb? stuff can hide in there...between nipple and the seat. did you try to blow in carb fuel inlet with carb right side up and upside down, that helps tell if float is sticking and needle and seat are good. does your gas tank cap vacuum vent properly? I had a ca that drove me nuts cause it did not vent. try running with the cap loose. Is the tank really clean? sounds like the choke on is helping to pull fuel from the tank with a restriction. Hope that helps.
 
Ok I went through the carb again. What I noticed was a small piece of brass stuck way down in the bottom of the tube below the idle jet. Just kept at it with air and a pic and it must of flew out from the air. It appears to run correct now. Choke full open. Now onto the fact that I believe I have purchased another bad 6v battary that won't hold a charge. First was a new Interstate. 6.05 volts at best. Took it back. Purchased a Decka. Charged it all afternoon only went to 6.30 v. Which is almost there. Was told 6.35v would be correct. Turned off and disconnected the charger but did not install the cables yet. This morning the battary was 6.19v. Is it bad?
 

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