Joyner 250 Popping after upgrades

Posts: 96

Hey guys,

I made two distict changes to my 2008 Joyner 250 at the same time and since then it has been popping. I thought it might be the weather, but it pops in 55F or 95F weather.

For reference prior to the changes the dealer took of the stock Air Filter off and put a small K&N directly to the carb, change the main jet to 137 or 138 I dont remember which one. The also just let the breather hose coming out of the head dangle.

In the configuration above it never popped in any weather.

Here are the recent Mods.

1. A 2500 RPM spring and 17Gram sliders from Edge PWR.

2. The small K&N air filter vibrated off the carb. So took the stock elbow and placed it back on. Then I put a larger 4 inch can K&N on the end of that. Then I placed the breather hose coming from the head back onto the stock elbow.

Any ideas on what would cause the popping and or how to fix it?

Thanks

Z

Posts: 96

I live at 3500ft but it pops at see level also.

Posts: 939

popping can be an exhaust or intake leak. I would check those first.

Posts: 96

Posts: 33

More often than not, a popping noise is known as detonation (this is bad), and it is a sypmtom of running lean. A popping noise has also been found to occur in rich conditions. You mentioned putting a bigger intake filter on, this may change air flow, The joyner 250 that we had at our shop had a uni filter, and we upped the jet to only 122. I would suspect you be running a tad bit rich but, again depending on your altitude. I could be wrong, but try putting the smaller filter back on and see if that changes anything.

http://www.kidnmekarts.com/upload/Videos/Howtos/Redneck%20Intake%20Video. wmv <---- is what it sounds like you did, if not, install your intake filter this way.

Posts: 96

Thanks

Would a larger main jet help richen it up if it i running lean?

I see guys talking about 145 main jets on buggy news like its the norm?

actually I am starting to doubt that I have a 137 Jet. That what the dealer said he put in, and didnt check when I had the carb off. I will take it off and check again tommorow.
Z

Posts: 96

I started thinking that maybe when the original smaller K&N filter fell off that I sucked in dirt into the carb causing a small fuel blockage that would make it run lean. Is this possible? I wont be able to clean until tommorow night.

Thanks
Z

Posts: 4216

when does it pop? at top end or part throttle. If its at top end you might be running rich with the elbow on. it is possible that some dirt got in the carb. I would pull the carb and clean it real good and see what jet you have in.

Posts: 96

I finally got the carb completely off and replaced the cheep screws in the bottom. The Jet is a 137. I cleaned it as good as could I with carb cleaner. I did not remove the electirc choke though. I just took out the two bottom internal jets and cleaned them and then sprayed it all aroung as best I could.

I put it all back together and it pops pretty good at the top end and then stutters as I let off. On the bottem end it does not pop at all. I pulled the plug and it was dark and dry. So I used some fine sand paper, cleaned it up and put it back in. Ran it up until it popped shut it off and pulled it. It looked almost identical to what it looked like after I cleaned it. It was dry and was pretty clean except for the remaining carbon I did not get off with the sand paper.

I am currently sitting at 3412ft above sea level and its 84 degrees. I also ran it with no elbow or filter on it and it did the same thing.

Any thoughts?

Thanks for all of your replies.

Scott

Posts: 93

Sounds like you're too rich. With the elbow on I was running a 130 and I'm at about 200 feet.