Post by dando127 on Nov 11, 2021 7:30:44 GMT
goose
Ok I have a '71 TNT 340 single with a HD22B on it and it will only run with 1/2 to full choke. But man does it run for about 200 yards, I mean hold on. The bottom end is from a 335 Oly with the 3/4" pto shaft. I went through the carb (short of popping the welch plugs) and installed new gaskets, H&L needles, and cleaned it up. What should I be looking for?
I'll swap the current 22B for another I have, but I'll need that carb some day.
goose/Ron
stomper
is the fuel flow freely from the tank? filters plugged? high speed jet maybe dirty i would take the carb completely apart and go over it with a fine tooth comb and put all new parts back in it there is not much that can go wrong with them.
goose
The return has fuel flowing through it, maybe not as much as it should. I have a new pickup filter in the tank and a new bowl filter on the bottom of the carb. Perhaps it's just starved for fuel? I will disassemble it and clean it again. First I'll just pull the H&L needles and flush/clean them. Next I'll also throw on a carb that I know is working. If that solves it I’ll scrub it up again.
Do you think this issue is completely carb? I hope so.
skidoonut3
check the pop off pressure very critical on the tilly and also I have had to drill the return fitting out a little larger.
cdem72
What are your lo and hi speed settings? Also, it could be a fuel line or filter leak or problem with the impulse port. If you have an aftermarket thread on filter, the threade part may be too long and it bottoms out in the bottom disc of the carb, thus allowing air leakage around the filter gasket.
goose
I'll check the impulse port too. Perhaps the gasket is not lined up correctly. I have new lines and a new bowl filter, and the filter is the same type I've used on other fine running 22Bs. FYI since my first post I've not had time, but hopefully this weekend I can get it solved.
goose/Ron
ELAN 335
Get those welch plugs out of there, the nozzle check valve sounds sticky.
olympique_mike
Make sure the LO screw is at 3/4 turns out from in all the way and the HI is 1 1/4 out. No good? You need to take the carb plates back off, back out the lo speed and hi speed screw a few turns, not completely out, and shoot carb or contact cleaner into the holes in the carb body (the ones you can see the end of the needles in ), that is the the fuel intake, and look in the venturi to see if cleaner is coming through the idle circuit hole , that's the tiny one on the bottom by the butterfly and the main circuit hole, that's the one up wind of the butterfly. It will shoot out in a steady stream...if not, you have your problem, try blowing air into the hole in the venturi, in reverse flow, then the other way. ....do the cleaner again. if still no fuel, you'll need to remove the welch plugs and clean the area inside the plug and the pin holes in there and possibly take out the screen and check valve in the main jet, then assemble again. Re assemble and set the screws again. Still no good? Now you need to raise the float / fuel pressure by dis assembling, and bending the aluminum float needle arm contact point up slightly from flush with the carb body. (closer to the diaphram contact) Having fun yet?
Words of caution: keep the brown tillotson membrane and re use if it's OK, (If you replaced it before and still have it, put it back in) BUT replace the black membrane and float diaphram and keep for later use as a gasket by cutting out the center.
all these gaskets and membranes can really only go back one way, but in rare cases, one gets together wrong so if in doubt, check again.
Ok I have a '71 TNT 340 single with a HD22B on it and it will only run with 1/2 to full choke. But man does it run for about 200 yards, I mean hold on. The bottom end is from a 335 Oly with the 3/4" pto shaft. I went through the carb (short of popping the welch plugs) and installed new gaskets, H&L needles, and cleaned it up. What should I be looking for?
I'll swap the current 22B for another I have, but I'll need that carb some day.
goose/Ron
stomper
is the fuel flow freely from the tank? filters plugged? high speed jet maybe dirty i would take the carb completely apart and go over it with a fine tooth comb and put all new parts back in it there is not much that can go wrong with them.
goose
The return has fuel flowing through it, maybe not as much as it should. I have a new pickup filter in the tank and a new bowl filter on the bottom of the carb. Perhaps it's just starved for fuel? I will disassemble it and clean it again. First I'll just pull the H&L needles and flush/clean them. Next I'll also throw on a carb that I know is working. If that solves it I’ll scrub it up again.
Do you think this issue is completely carb? I hope so.
skidoonut3
check the pop off pressure very critical on the tilly and also I have had to drill the return fitting out a little larger.
cdem72
What are your lo and hi speed settings? Also, it could be a fuel line or filter leak or problem with the impulse port. If you have an aftermarket thread on filter, the threade part may be too long and it bottoms out in the bottom disc of the carb, thus allowing air leakage around the filter gasket.
goose
I'll check the impulse port too. Perhaps the gasket is not lined up correctly. I have new lines and a new bowl filter, and the filter is the same type I've used on other fine running 22Bs. FYI since my first post I've not had time, but hopefully this weekend I can get it solved.
goose/Ron
ELAN 335
Get those welch plugs out of there, the nozzle check valve sounds sticky.
olympique_mike
Make sure the LO screw is at 3/4 turns out from in all the way and the HI is 1 1/4 out. No good? You need to take the carb plates back off, back out the lo speed and hi speed screw a few turns, not completely out, and shoot carb or contact cleaner into the holes in the carb body (the ones you can see the end of the needles in ), that is the the fuel intake, and look in the venturi to see if cleaner is coming through the idle circuit hole , that's the tiny one on the bottom by the butterfly and the main circuit hole, that's the one up wind of the butterfly. It will shoot out in a steady stream...if not, you have your problem, try blowing air into the hole in the venturi, in reverse flow, then the other way. ....do the cleaner again. if still no fuel, you'll need to remove the welch plugs and clean the area inside the plug and the pin holes in there and possibly take out the screen and check valve in the main jet, then assemble again. Re assemble and set the screws again. Still no good? Now you need to raise the float / fuel pressure by dis assembling, and bending the aluminum float needle arm contact point up slightly from flush with the carb body. (closer to the diaphram contact) Having fun yet?
Words of caution: keep the brown tillotson membrane and re use if it's OK, (If you replaced it before and still have it, put it back in) BUT replace the black membrane and float diaphram and keep for later use as a gasket by cutting out the center.
all these gaskets and membranes can really only go back one way, but in rare cases, one gets together wrong so if in doubt, check again.
