Tecumseh/Lauson Carburetor Adjustmen

[Kristof]

Hi,

I need help adjusting this old carburetor. I have found an "H" on it, but I have not found an "L". I dont know which screw is which, but Im guessing the one the right is "High" mixture or "Main" mixture?
(The one on the left is actually bigger than the one on the right.)

So far the engine surges at idle and at full it pops really loud.
Are there any instructions on how to adjust this carb. or at least diaphragm carbs.?

https://lh3.googleusercontent.com/_t5uyKe3qmIs/TV3bhHWtjAI/AAAAAAAAAWs/U8jKsRVP0vw/s912/IMG_0060.JPG

https://lh3.googleusercontent.com/_t5uyKe3qmIs/TV3bhe6UnxI/AAAAAAAAAWw/5WYJNU4F2Es/s912/IMG_0061.JPG

 

[curtisfox]

Looks like the front would be the high. Turn the high in all the way untill it stops then back out about a turn and half try that. Final is the fastest rpm you can get with the throtle partly open and open a quater turn more. The other should be ajusted so that there is no hesitation between idle and high rpms..........Curt

 

[Kristof]

I tinkered around with it yesterday, but no luck. Is it possible that the diaphragm has become stiff? The engine has been sitting around for around 12 years, but no fuel in it though.

Related question: How do I hook up a throttle to this thing? What kind of a throttle do I need?

 

[curtisfox]

Best to get a rebuild kit then try it. What is the engine off of and how much HP?

 

[cannonball2]

You can get a kit for this carb from a small engine shop. I can just about assure you the diaphragm is shot. The H needle is the high side, adjust @ WOT for max power, adjust the other needle for smooth idle and transition. You generally have to work them both towards each other so to speak to get a properly adjusted carb. These were generally seen on the 3-3.5 engines.

 

[Kristof]

How do you know if the diaphragm is shot? Is it from the sitting around for 12 years?

What does WOT stand for?

Thanks,
Kristof

 

[professor]

WOT is wide open throttle. Throttle depends on wether or not you want the governor working. If you don't want the gov. just hook up your throttle cable to one of the holes in the throttle on the carb- you will need to adapt something like the hard wire to a flex cable
I braise a brake cable type clamp onto a bit of hard wire and send the flex wire thu it and lock it down - an adapter.

By the way, I suspect you could swap a float type carb off a Techumseh mower or snowblower.
I like the float carbs better- less to fuss with and no diaphram.
The newer carbs have a primer bulb rather than a choke. They do not have a screw type idle speed stop- just a tab to bend ,but neither do they have an idle circut that gets plugged up like the old Tech. float carbs.

 

[Kristof]

Could you show me how to link up a brake cable to the governor, I dont seem to understand "flex cable".

I think I will order a new diaphragm, but how do I know which one to order and where to order from?

My model number is unclear: something like 631032 or 634032 or instead of 32 it might be 82.

My serial number was clear: 33610

 

[Kristof]

I think I will do something like this for the throttle:

 

[cannonball2]

The float carb will bolt on and the direct linkage hook up is basically the same. The float carb is simplier to understand and work with for most people, but the pumper is also a good carb, but it depends on the diaphragm which has a given life span, for proper operation.

 

[LS614]

Ah, one of those carbs. I have a love hate relationship with the Lauson carbs, I think that is the exact one I have. They are tricky little buggers, and I have spent hours adjusting mine. but I think it is finally working right. I may be able to get you the exact tuning instructions, let me see here ya go http://www.google.com/url?sa=t&sour...QWNBeAOzQ&sig2=l5qJAxnJcwzC5kmYK-rebA&cad=rja try looking at page 20 first, that's what always helps me Good luck!