Hesitation usually happens in 3rd during acceleration. It's like 3 or 4 quick jerks then ok. My primary chain is to specs. I'm beginning to think my acceleration pump diaphragm needs replacement. Anyone experience this?

My bike is 20 years old 1200xlh, it's in very good condition.

Thanks for the responses.

 

We need alittle more info like are you just puttin in 3rd then hammer it and it sputters or are you on the gas from 2nd to 3rd and it happens,give a few more details.

 

Right when I put it into third. Like when I'm about to go on a freeway. I've noticed if I really hammer it in 3rd it seems to not happen as often.

 

How long has it been since the 20 yo carb was disassembled, cleaned and rebuilt? If it's more than 6-7 years, it's due.

Hesitation caused by the accelerator pump is usually most pronounced off the line, as in starting out in first gear from a stop.

 

The carb has never been cleaned. I have all the parts for a rebuild, I guess I'll have to tackle this soon. In your estimation, on a scale of 1-10 for an intermediate mechanic, what would you say?

ps- thanks for all your responses in this forum, I've learned a lot.

 

Oh good god! Yeah it's due. If you've got a repair manual it should be a piece of cake. If you've done lawn mowers or small engine carbs, it's a piece of cake without the book too.

 

Most likely it is the tranition from your slow to main jets. This diagram may help:

 

Rink, good diag.

 

Is there an adjustment screw for this? Or how can I correct this?

Thanks.

 

The only "screw" adjustment is for the idle mixture. The pilot and main are fixed jets, you tune them by replacing them with different sizes. I wouldn't worry about changing jet sizes at this point though, cleaning and rebuilding are your priority. If you are at all mechanically inclined, the carb rebuild is pretty easy and inexpensive.

Also, don't get to stuck on the above diagram as it really isn't a good representation of the transitions in a CV carb. The main jet in a CV doesn't even come into play until you hit 3/4 open on the throttle.