When giving it throtte the is a hesitation or slow response before it kicks in and goes once it takes off runs pretty good. This is a 2 stroke. I have replaced the plug looked like it may be running a little rich. Any thoughts would be helpful.

 

If the carb is set too rich, what you'd describe will happen. I would try and lean out the carb to see if that takes care of the problem.

 

That was my next step, to try to make it run a little leaner. Been trying to find info on adjusting the carb. I do not want to cause more problems.

 

http://www.dinlisales.com/products/jp_50_pics.html


Here is a website that has a parts and service manual online. The manuals were photo copied and are very poor in quality. I was looking for carb adjustment instructions and did not find anything. Give them a call and see if they can help.

 

Made adjustments to the carb but did not seem to help the throttle response. Decided to check compression but not sure if pressure gauge was good. Compression showed 20 psi. I would think this bike would not run with that low of compression. The bike seems to run fine after it kicks in. Any thoughts anybody.

 

I realize this is a 10 year old thread but I imagine there are still a few JP50s out there that are running poorly. Mine had run badly for years. Taking the carb apart and cleaning it seemed to fix it for a bit but the JP always reverted back to its habit of running very lean and would only run with the choke partially on and then run not very well. I purchased a carburetor online, probably from China, that claimed it fit the JP as well as other Dinli models. It didn't come close to fitting!

I then tried to find a rebuild kit for the Walbro. I ordered this kit.

Walbro Repair Kit Part # K10-WJ

It did the trick. The little JP runs as good as ever. My grandkids, nieces and nephews are very pleased. I think the main problem was the small diaphragm had gotten stiff and wasn't letting sufficient fuel into the engine. The kit only cost about $8. Wish I'd thought of it sooner.

 

I know this is an old post - but I am having issues with the original Walbro carb (WJ-98) - I bought the rebuild kit - fitted it but the carb still hesitates and over fuels... how do I tune these carbs? I see it has two smal red caps on the side - turns just a few mm in either direction - tried everything and same result ...

 

oki - so after I broke out the factory fitted red caps - was able to tune the carb ...