Jump to content

Crf150rb running badly

Recommended Posts

Hi all, I have a 2007 Honda crf150rb that isn't running the greatest. When ever you nail the throttle it kind of hesitates not bogs but hesitates for a second until going to full throttle. It kind of mimics a 2 stroke powerband. If you nail the throttle in a higher gear (4th or 5th) it won't bog it will rev up and sputter for a few seconds until going to full throttle. It also pops on decel. Valves were also just shimmed and are all in stock. Jets are 135 main, 48 pilot , and the rest are stock. Clip is at 3rd position on the needle where it's supposed to be from the factory. Fuel screw is at 2 turns out. Has fmf powerbomb header and q4 muffler with spark arrestor removed. Any help would be greatly appreciated

Share this post


Link to post
Share on other sites

AP timing is a possibility, if it has been messed with. Could be too early or too late. I had a 4-stroke with a bog...tried o-ring mod and jetting Pilot and needle...still bogged...tried to adjust AP timing by the seat of my pants...no improvement.

looked at carb with my video camera while I whacked the throttle open...could see the AP fuel stream start too early and hit the carb slide on its way up! I adjusted the AP timing so that the AP fuel stream just missed the slide on the way up...holy cow!!! the throttle response is amazing...

Bike is a 2006 WR250F.

Share this post


Link to post
Share on other sites
1 hour ago, luke8500 said:


I've done the o ring mod and it helped a little bit. What else should I do to the ap?

I'd start with simply pulling the air boot off, aim a flashlight in the carb then have a friend quickly turn the throttle and confirm the AP has a strong shot.

If this problem is a recent occurrence, then for sure, it needs to be serviced. If it has always been this way then as Sofiedog says, the AP timing needs to be checked and possibly a smaller leak jet considered.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×