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Filthy exhaust


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Hey guys, I'm pretty new to two strokes so sorry for newb questions... But I am mechanically inclined and willing to do some research. That being said the issue i'm having is on a 1991 YZ250 (with an Ohlins big bore kit) the exhaust has lots of nasty goop in there which is beginning to drip where the muffler connects.

So first question is what is the source of the issue, is it running too rich? Bad gas?

Second, do I need to replace the exhaust or can I clean it out with a solvent or burn it out somehow?

Thanks in advance

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Jetting, you can get a power washer and run it through the expansion camber, there is supposed to be a rubber boot their also. you have to jet leaner when you get a big borr kit. Get a couple smaller main jets from the oem size and go down one at a time. What kind of riding are you doin? What ratio?

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well right now I'm not doing any riding other than around the neighborhood 😏 But I'm just looking to do some trails, I'm a little older and more than anything I wanted a cheaper motorcycle project that I could learn about two-strokes. Then when my son gets older I'll get him one. Anyway, I forgot to mention that it's blowing smoke everywhere... I'm sure cleaning out that expansion chamber will help clear some of that up. There is the rubber boot on there but it's not attached very well... It's loud as hell so I don't think the muffler is doing it's job.

I'll look around for some new Jets and give that a shot.

The bike has many issues, but so far it's pretty fun to ride 😏

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Def your jetting... a couple tips that may help as well would be to make sure your premix variables stay consistant. Meaning use the same oil, same ratio, and same fuel from the same place when at all possible and it will keep jetting more consistant.

Next would be to make sure your air filter stays clean as this will also effect your jetting. esp if you over oil your filter or its extremely dirty (it will run rich)

After that Id reccomend repacking your silencer as this may help with the noise and will keep the spooge from dripping out of the end of your silencer.

And my last bit of info would be to use the search feature to learn how to do plug chops, and how to read plugs. This will make the jetting process much easier on you if you dont have much experience in the area.

Also rem its a two stroke so if your not opening the bike up every once in a while it will load up and run rich until it fouls a plug or you get it cleared out which usually only takes getting the rpms up for a couple seconds because of the amount of unburnt fuel. All the things I mentioned are very cheap and inexpensive ways that can get and keep your bike running in tip top shape! but you have to keep up with them and maintain the bike regularly.😏

Sorry for the long post but hopefully it will be helpful and good luck!😏

Edited by ftball90
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Yup, definately jetting. +10 on all that is prev said, but make sure you pick an oil and pick a ratio and stick with em, or jetting will become an exercise in frustration and futility. Welcome to 2 strokes, the most fun you can have without drugs!!!!

Bob

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ftball90, I appreciate the direction, longer the post the better! Sometimes with projects all I need is to be pointed the right way, I'm certainly not scared of the search feature but having a headstart is great :banana:

Thanks for the solid info, I'll post back when I get it worked out.

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