67 sears allstate almost running

Hey out there. I have a '67 sears allstate compact scooter (puch) that I have owned for 20 years. Just fired it up last week and put plates on it, and all is good, but for one problem. I start it and it runs great. About 2 minutes into the ride I start losing power and have to decrease throttle. Then sometimes the power comes back, and sometimes it bogs down more. I do not know a whole lot about Bing carbs, but it sounds like a mixture problem. Black plug, lots of smoke when the power loss occurs. Bing carbs of this ilk only appear to have an idle screw on the side. Any help or suggestions would be appreciated. Thanks a lot!!! T

Re: 67 sears allstate almost running

The needle inside the carb can be adjusted up or down Puchs usually have this set to one notch up from the bottom. You can adjust your Midrange and ratios this way, the Carb gasket usualy must be replaced once the carb is opened keep the original and cut a new one or buy one or you will most likley have a leaking and malfunctioning Carb unless this is done.

Re: 67 sears allstate almost running

Jason Luther /

i know you put fresh gas and a new plug in there right? check the airbox/filter for a beehive or somethimg too.

Re: 67 sears allstate almost running

sounds like it's running rich.. too much gasoline or too litle air. Since the bike runs great and the trouble is intermittant i wouldnt bother adjusting or cleaning anything..

i dunno what kind you have but some Bings have a vertical, manually operated choke plate .. i had one and the choke plate occasionally slipped down due to vibration while riding. But when opening the throttle, a tongue on the slide pulled the choke plate back up and the bike usually recovered.

Look for something similar.. something that could cut off air supply. If you cleaned the carb be sure it was reassembled correctly ..

Re: 67 sears allstate almost running

You may have a clogged muffler.

Try running without the muffler.

Re: 67 sears allstate almost running

Thanks alot...the thing runs great after I reset the needle in the carb. Still a little drop off in power...but no stalling anymore. Maybe need to reset my timing. I'll let y'all know how it comes out. Thanks again...thetimmer

Re: 67 sears allstate almost running

What about the spark plug?

Have you put in a new one?

If it is getting gross fast, it may not be sparking well.

If it misses a beat every now and then, your plugs will foul up, and it will run poorly.

Clip the spark plug wires on both ends, and reterminate the connections at the plug cap, and boot. Clean the points, and put in a new plug.

Your symptoms sound just like mine did, I did that stuff, and now I'm cruising.

Re: 67 sears allstate almost running

Disconnect the fuel line at the carb and see if you get a good tream of fuel when the tap is opened. The filter in the tank might be plugged. It might be starving for fuel. That is why when it bogs you are getting too much air in relation to the amount of fuel thqat i flowing and when you close the throttle you choke back the air and bring the fuel/air ratio back into balance.

It is also possible that your fuel tank vent is plugged. When it bogs try opening the cap to see if it clears up.

Re: 67 sears allstate almost running

check for clogs

Re: 67 sears allstate almost running

BOGGIN ON A 2 STROKE CAN BE DOWN TO BLOCKED EXHAUST,

i WOULD ALSO CONSIDER THE FLOAT MIGHT BE STICKING AND CAUSING THE CARB TO FLOOD INTO THE ENGINE

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