Tecumseh 4 hp carb

[Airmaster Flyer]

Thanks for the comments.

I have a soft bound Tecumseh book called "Mechanic's Handbook" for 3 - 10 HP engines. On the back it says "R2/93" which I presume means "Revision 2, 1993. I also have a Tecumseh "Technician's Handbook" for 3 to 11 HP L-Head engines dated 1998 that I downloaded from the internet at some point. I also have a CD titled "Tecumseh Repair Manual" dated 2005. All are good for explaining how to adjust the original carb, but none mention a carb with no idle or main jet adjustments.

I will check out the link on repair tips, but as I said, right now all I wanted to know was if there was a way to adjust this carb without a main jet adjustment screw, since in my close to 60 years of messing with theses small engines, I have never seen one before. According to Hammer, the answer is that maybe I can install an adjustable bowl nut on my new carb, or maybe not. For now the engine is running pretty well, and if it is a little rich, I am going to live with it for this Winter.

Bob

 

[mmoffitt]

Run what you brung'...it's a snowblower, not a Heart-Lung machine....now for some snow!

 

[shadetree#1]

AirMaster flyer asked:
I will check out the link on repair tips, but as I said, right now all I wanted to know was if there was a way to adjust this carb without a main jet adjustment screw, since in my close to 60 years of messing with theses small engines, I have never seen one before.

You say you have never seen one.
The non-adjustable jet replacement carbs for small engines came about due to emission regulations. Al Gore type carbs.

You think maybe yours is running too rich. I've modded several of the non-adj jet carbs so as to make the engine run smoother but usually I had to enrichen them by modding the idle jet circuit BECAUSE the idle ckt is also used to enrichen the High jet area on those emission carbs.
On some of the Tecumseh non-adjustable carbs you can remove the low speed idle jet tube and play with modding it. If your replacement carb cost very much in $$'s I would suggest leaving as is and fix your OEM carb, because you stand the chance of ruining your replacement carb and having to spend more bucks. (Some replacement carbs
Some of the Tecumseh carbs fixed low speed jet brass tube could be taken out of the carb with the carb on the engine and they have a color code plastic cap indicating their size. When I first started modding the carbs i made sure that I could get a replacement low jet tube BEFORE I started modding the carb. (if the carb was the expensive type replacement)

 

[Airmaster Flyer]

"The non-adjustable jet replacement carbs for small engines came about due to emission regulations. Al Gore type carbs."
That explains a lot. This snow thrower was purchased in 1987!

Happy New Year to all...Today it is warmer outside than it is inside! But there is bound to be snow sooner or later.

Edit: This new carb does not have a low speed adjustment either. The spot where it would be is plugged. Next Spring I may remove it and see if the adjustable bowel nut from my old carb would be direct screw in replacement. If not, I will just leave it alone.

I had replaced the carb at some point, and so I have two old ones. One does have a brass sleeve for the needle seat, but it is not obvious how it would be removed as there is no slot for a screwdriver or flats for a wrench or socket. Appears to have been pressed in. The other does not have a separate brass sleeve at all, as if the carb is a throw-away.

Today afternoon high of 67F, so no snow!