Jump to content

CRF150R POPPING ON DECEL

Recommended Posts

I have a 2007 Honda crf150rb that pops whenever you let off the gas. Valves were just shimmed and they're all in spec. Jets are 135 main 48 pilot and rest are stock. Fuel screw is at the factory 2 turns out. It has an fmf powerbomb header and q4 muffler with spark arrestor taken out. I'm thinking that might be it but I want to get the opinions of some other people.

 

Thanks

Luke

Share this post


Link to post
Share on other sites
On 8/24/2017 at 10:27 PM, luke8500 said:

I have a 2007 Honda crf150rb that pops whenever you let off the gas. Valves were just shimmed and they're all in spec. Jets are 135 main 48 pilot and rest are stock. Fuel screw is at the factory 2 turns out. It has an fmf powerbomb header and q4 muffler with spark arrestor taken out. I'm thinking that might be it but I want to get the opinions of some other people.

I'm quoting CRF DOC here: "Decel pop is most commonly caused by a lean condition in the pilot circuit or an incorrectly adjusted fuel screw, a missing o-ring or washer on the fuel screw, a partially clogged pilot jet, a clogged passageway above the pilot jet, or a poor sealing crush gasket at the header can all be causes of decel pop."

From this thread:

Edit: note that the crush washer at the exhaust port is designed for one-time use.

Edited by Old Plonker

Share this post


Link to post
Share on other sites
I'm quoting CRF DOC here: "Decel pop is most commonly caused by a lean condition in the pilot circuit or an incorrectly adjusted fuel screw, a missing o-ring or washer on the fuel screw, a partially clogged pilot jet, a clogged passageway above the pilot jet, or a poor sealing crush gasket at the header can all be causes of decel pop."
From this thread:
Edit: note that the crush washer at the exhaust port is designed for one-time use.

If I leave it alone will it cause engine damage?

Share this post


Link to post
Share on other sites
6 minutes ago, luke8500 said:


If I leave it alone will it cause engine damage?

If it is the crush washer it might cause erosion of the gasket face making a good seal impossible later with a new gasket. If it's any of the other things, it will just be a pain in the ass to keep it running clean. 

If it were me, I'd chase down he problem and fix it. If you do get into the carb, do yourself a favor and install a flex screw in the pilot circuit. It makes pilot tuning SO much easier.

Share this post


Link to post
Share on other sites
If it is the crush washer it might cause erosion of the gasket face making a good seal impossible later with a new gasket. If it's any of the other things, it will just be a pain in the ass to keep it running clean. 
If it were me, I'd chase down he problem and fix it. If you do get into the carb, do yourself a favor and install a flex screw in the pilot circuit. It makes pilot tuning SO much easier.

Alright thanks for your help I’ll try it

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:


×