missing part on carb

[x308]

After cleaning my carb & installing a new kit, I noticed that the ORIFICE PLUG was missing. My engine, 1976 35hp, runs great at high speed, but coughs at lower speeds. If you click on the link to my web site it shows the part.

http://www.geocities.com/x308/carb.jpg

Can anyone tell me if this would affect the low speed? And what’s its purpose.

 

[x308]

Re: missing part on carb

Sorry part # is # 31

After cleaning my carb & installing a new kit, I noticed that the ORIFICE PLUG was missing. My engine, 1976 35hp, runs great at high speed, but coughs at lower speeds. If you click on the link to my web site it shows the part.

http://www.geocities.com/x308/carb.jpg

Can anyone tell me if this would affect the low speed? And what’s its purpose.

 

[Bob_VT]

Re: missing part on carb

That is the float bowl drain. It will not affect low speed. Do you have a "bolt" in the bottom of the carb? That is all that is (a brass bolt with a fiber washer).

The low speed circuit is on top of the carb and there are 2 or 3 tiny pin holes inside the carb for low speed.

Your low speed circuit could probably stand a good cleaning. A ton of factors have varied effects on idle. I am battling a compression variance in my old motor.

Clean/rebuild the carbs, it is easy they are simple carbs.

 

[OBJ]

Re: missing part on carb

Behind the drain bolt that Bob spoke of is the high speed jet. If it's running great on high end, likely everything is in place in the bowl.

The "cough" you refer to may be a lean cough. Open the low speed needle about a half turn more and see if that solves the problem.

Also refer to FAQ section for a thread on low speed needle adjustment by Joe Reeves. Should help.

 

[x308]

Re: missing part on carb

Thanks for the help, I did find that the jet was in there just further in and I needed a light to see it. The tuneup manual states that the needle should be open 1 turn. I've been informed that two turns is what it should take. I also was shown a few tricks to try with cleaning the carb.