Running super rich during break-in

berrytoucher

New Member
Local time
7:49 PM
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Jun 6, 2023
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Location
Georgia / Atlanta
Hey friends! First post here, sorry if I’m breaking some rules or something.

I’m left scratching my head a little. I’m probably 20 miles into the breaking period, I’ve already soiled a spark plug and had to replace (fine by me putting in an NGK instead of whatever crap they sent me), but I could tell from the state of the old one that I was running very rich. Before I got the bike cranked again with the new spark plug, I changed the clip in my NT carburetor to run as lean as it will allow by that adjustment method. Since I’m still in the break-in period, I’m hesitant to start messing around with the jetting. Do you guys have recommendations on how to lean out the mix without changing the jetting?

In some other threads I’ve seen recommendations as to air filters. Would that perhaps fix my problem? If so could someone drop a link to a recommended product?

Thanks guys! This forum has been a huge help getting me up and running.

P.S. I have absolutely no mechanical knowledge beyond what I’ve learned on this project. If you wanna check out a bit of my journey I made a YT video about it :)
The Video
(I said something in the video that might seem like a shot at the forum, it totally wasn’t, I read that in a product review. I love you guys!)
 
I found your video hilarious...lol...lol...Especially letting your girlfriend loose on it as she careens towards the parked car...Just glad she didn't get hurt...I do see though that she is not gonna ask you to build one for her anytime soon just so she can go on rides with you...lol.

 
As far as how lean your gonna want that, tell me what your elevation above sea level you are at...If you have either the BoFeng or NT carby, I can tell ya where to set the C clip on the needle that you should be at...Keep in mind that running too lean is the death of these two strokers.
 
As far as how lean your gonna want that, tell me what your elevation above sea level you are at...If you have either the BoFeng or NT carby, I can tell ya where to set the C clip on the needle that you should be at...Keep in mind that running too lean is the death of these two strokers.
It's a BoFeng, but with the black skull looking air cleaner cover instead of the red one like what we have on the Phantom. Not sure if they use he same jets though. I've never had the style his came with.


I’m left scratching my head a little. I’m probably 20 miles into the breaking period, I’ve already soiled a spark plug and had to replace (fine by me putting in an NGK instead of whatever crap they sent me), but I could tell from the state of the old one that I was running very rich. Before I got the bike cranked again with the new spark plug, I changed the clip in my NT carburetor to run as lean as it will allow by that adjustment method. Since I’m still in the break-in period, I’m hesitant to start messing around with the jetting. Do you guys have recommendations on how to lean out the mix without changing the jetting?

In some other threads I’ve seen recommendations as to air filters. Would that perhaps fix my problem? If so could someone drop a link to a recommended product?

Thanks guys! This forum has been a huge help getting me up and running.

P.S. I have absolutely no mechanical knowledge beyond what I’ve learned on this project. If you wanna check out a bit of my journey I made a YT video about it :)
The Video
(I said something in the video that might seem like a shot at the forum, it totally wasn’t, I read that in a product review. I love you guys!)
Likely you need a jet change. If you have it leaned out fully on the needle and are still fouling out plugs, that's a good indicator. BUT, before going down that road there is also the chance you have a float needle not seating properly and thus not fully shutting off the fuel to the bowl. Or, the float height is set too high, also over filling the bowl. Either case would cause a rich condition, the former would usually present itself in other ways like fuel leaking out of the carb itself.

As Chainlube mentioned, you also need to keep an eye on the fasteners of these engines during break in as they will loosen, and that can cause air leaks.

Other things to check and adjust would be on the ignition side of things. Make sure the stator arms for the CDI system are gapped evenly on both sides of the magnet. If one side has a larger gap than the other the ignition may not be firing consistently, or may have a weaker spark that is not igniting the mixture due to spark suppression from the cylinder compression - electrical resistance increases as atmosspheric pressure increases.

Others will likely chime in with other suggestions as well.

If all else fails, drop down one size on the main jet and put the needle back to the middle notch. Normally BoFengs come with a 70 main jet, so step down to a 68 and see how it behaves. The only real danger to a slightly lean condition is when under high RPM and High load. Being lean at idle or middle throttle can still cause some heat related problems, but catastrophic failure tends to happen when pushing a lean condition HARD for a length of time. Going from a 70 to a 68 won't create a dangerous lean condition (for people with common sense at leaast), assuming it makes it lean to begin with.
 
To answer the questions:

I'm about 1000 feet above sea level (sweet Atlanta GA)

I bumped my C clip out to the leanest position on my most recent (brief) ride and it seemed to help but only slightly. I'm having mounting issues that I need to fix before I ride again so I won't be able to test any fixes until I get that fixed up (post with pictures coming later).

Pretty sure I'm running 40:1 (I know that might be thin compared to what I've seen recommended on here but I haven't quite burned through the tank of gas yet). I mix the oil in a gas can. Gas+oil+shaking it up.

I have a feeling that my float needle isn't seating properly, because there's always fuel present on the outside of my carb's bowl. I used to have a fuel line/filter leak so I assumed it had dripped there, but I fixed that weeks ago and I'm still having a little fuel on my bowl at all times.

I can check it out on my own but if you have tips on what I'm looking for @ImpulseRocket that would be really helpful... if you watch the video you can pick up pretty fast that I have no background for this whatsoever :)

And @DAMIEN1307 thanks for the love on the video... you're right, she is not gonna ask for a bike any time soon. I was hoping she'd want to ride but it doesn't seem that way now. I'm just very grateful she managed not to crash it.
 
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