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The Snow Man
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142 Posts
Discussion Starter · #1 · (Edited)
Hey all. My 440 kawi with a Tillotson Carb on a 72 Cat chassi will flood out if I rev it up and let off right away. A friend of mine told me this was because the level of the fuel is higher in the tank than the level of the line that enters the carb. It just dumping all the fuel into the engine. Is this true?? This is a "hybrid" I put together with extra parts so it doesn't have the correct fuel tank. Shouldn't the needle and seat stop this? I've been playing with different springs on the needle and seat (pop-off pressure) but nothing is helping. The engine was just rebuilt as well as the carb. If I just go out and ride and keep it tached up it will run great, or if I just start it up and let it idle it's fine. I'm stumped...



Thanks,

Fess
 

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dont listen to your freind he is wrong, if you look at the new sleds the tank is higher than the carbs and they dont flood out.you dont have the fuel line and the return line reversed do you? how many turns out are you on the adjustment screws? have you set the "float" height? the arm should be level with the housing.how does it run at say 1/4 or 1/2 throttle?
 

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The Snow Man
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142 Posts
Discussion Starter · #3 ·
Thanks for the reply. I was thinking his logic was wrong. There are no floats on this carb. Its a diaphragm Tillotson carburetor. I set the tang on the needle level with the housing. The lower line is the intake on the tank. It also has a 1 way check ball valve so no fuel can flow back into the tank. The return line is the higher one on the tank. It has no line inside the tank. I'm getting upset with this sled because it was running great 2 weeks ago when there was very little snow. Now we have 10+ inches its pulling this crap. I have both the high and low jets out 1 turn to start off with. I just ordered new needle and seats as well as new welch plugs so I can have a look at the main jets this time. I just did gaskets at the start of the season so I'm hoping this will do the trick. It has to be something with the damn carb. Is there something I could have done wrong when I put the engine back together to make it suck too much fuel? Compression is even in both jugs, 137psi btw... If the carb is workin correctly shouldn't all of the unused fuel be sent back into the tank??


Thanks,

Fess
 

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I'm not much help , but i am having the same type of problem with the tillotson hr-16b on my 1971 ski-doo. i would like to know what you find out .
my carb won't run on the factory settings of 3/4 low and 1 1/4 high. it was bogging real bad so i leaned it out and was amazed at how good it was running saturday. i rode sunday and on the way back it would hardly run, it seems to be starved for fuel when i get off the throttle but will idle all day. no amount of mixture settings made any difference.
good luck.
 

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The Snow Man
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142 Posts
Discussion Starter · #5 ·
Well as it turns out the seat was bad. It would not seal all the way. I also went up one spring size on the tang. It runs perfect now. To top it off we got 8" of snow yesterday and more comming Friday!! :D Looks like things are looking up. However I do have one more sled to get running (72 Puma 440). Parts should be here tonight. Wish me luck..


-Fess
 
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