Poor initial acceleration

I know this is probably a commonly asked question, but I have been unable to find helpful posts.

I have a '79 Batavus that I recently ressurected. It starts fairly easily, and idles, but when I go to accelerate it is very slow. It dies with too much gas, and basically I end up having to pulse the gas to get it to go at all- too little gas and it will stall. After a lap around the block at about 5mph, it gets better, and better until it accelerates well. To get full acceleration though, I have to repeatedly drop down from full throttle and come back up, it sounds like I am shifting gears (bystanders might think I had a 10-speed or something).

I have air-blasted the carb, checked compression, good spark... would a clogged exhaust able to accelerate well after a lap around the block? I dont think my clutch is slipping because the RPMs correspond to the low speeds.

Any help would be great

Re: Poor initial acceleration

I discovered today that this problem can be resolved by pulsing the choke. This doesnt seem meant to be though- is there anything I can do?

Re: Poor initial acceleration

Steamboat Aka J. R. Stevens /

The choke should only be used to start a cold engine. Jim.

Re: Poor initial acceleration

Leon Swarmer /

Ahh that pulsing the choke is a great clue..sounds like it is starving for gas. When you got to WOT is's getting a lot of air but not enough gas. Do you have a mixtrure screw on this ped?

if so turn it a half a turn at a time and see if one direction seems better than another..

Leon

Re: Poor initial acceleration

I dont think I have a mixture screw, unless it is the same as the one holding the jet. My carb somehow has no idle screw but a flat place where one would go, and no choke cable outlet (I added one)...

Is a poorly set mixture screw consistent with it running better after an embarrasing half mile or so?

Re: Poor initial acceleration

Leon- well, you were pretty much right: not enough gas. I took the jet out and it was clogged by a tiny ball of fibers. I soaked the whole deal in cleaner, and put on a new gasket, and she started right up with good acceleration.

Thanks,

Andrew

Re: Poor initial acceleration

Leon Swarmer /

Way to go.. Glad you got it.

Leon

Re: Poor initial acceleration

If you want even more pickup you could get a smaller sprocket for the back.

Re: Poor initial acceleration

Steamboat Aka J. R. Stevens /

I think a smaller sprocket on the back gives more top speed if your engine can turn it. Jim.

Re: Poor initial acceleration

larger sprocket in back for better pickup at expense of top speed

Re: Poor initial acceleration

basic stuf cleen the carb, change the air filter, check the spark gap, be sure that you gave good gas in it, and make sure the chain has the right amount of tension

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