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Discussion Starter #1
Has anyone rebuilt an old Tillotson carb? I have mine compleatly apart other than: main jet, needle valve seat, and the plugs for the high and low jets. Everything else is functioning properly but I'm still not getting any fuel and I dont know what to do with these parts. Does anyone have any advice?
 

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Those carbs can be a royal pain once they get older. Take out all your jets counting the turns so you know about where they go when you put it pack together.
Flush with a can good and strong carb cleaner and blast out with compressed air.

Its real easy for those jets to get plugged with crap.
Also, are you installing a rebuild kit, the fuel pump diaphram in the bottom of the card might be f'ed up. Replace filter if you cant blow through it easily.

Good luck
 

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Discussion Starter #3
Well I got the thing cleaned out as best I could and put it back on the sled. I did not know where the jets were so I just guessed. It runs but very roughly so I tried to adjust the jets but It made no diffrence, right now I have them both tightend to the seat and it still runs the same as if they were open? Then with the jets closed tight, I unhooked the crank case hose for the pump and that did'nt even make a diffrence. Where is it getting fuel from, and why would it still run if there is not pressure to run the pump?
 

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there is tons of info and parts available for that carb. this site a a manufacturer manual covering anything you need to know
http://www.bayshorecad.com/Sleds/CarbManuals.html
i have JUST put one of those on my sled and its a releif from the walbro i had on it, i like the fact that i have tons of part available to me for this carb.
you may want to break down and put a whole new rebuild kit in it
www.mfgsupply.com
 

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Discussion Starter #5
thanks, even though they may be a pain in the a$$, I still love those old sleds and their parts. They are about half as complicated as new ones. Great website by the way!
 

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Discussion Starter #6
Just out of curiosity, what fuel mixture should I be running? The engine is a 1971 Hirth 440. Someone told me to run 50/1, but I'd like to be sure.
 

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With the quality of oil being so much better then it was in 71, you would prob be fine at 50:1. However, It wouldnt be bad to run 40:1 just for safetys sake. Im sure your engine was prob designed for 20:1. I can even remember my grandfather using 10w-40 @20:1 for his old skidoos.

As for the carb. Are you sure you put all the wafers back in the correct orientation? It def shouldnt run with the jets all the way into the seats, or with the pulse line off for that matter. possibly left over fuel in the case? How long did you run it for like that?

I guess it could be possible that either your seats are corroded and still allowing fuel to pass by or there is still crud/dirt in there that wont allow the needle to seat all the way.

Did you blow out the passages with compressed air and good carb cleaner?
 

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Discussion Starter #8
It ran for a couple minutes like that. I blew out everything I could with compressed air and a carb cleaner, then I ran a thin wire through all the small holes. It really smokes when it is running like that, something is definatly F'ed up.
 
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