Yeah
I was wondering what type of spark plugs, and gaps all of you guys run in a TRX 250R. Mine is a 1986.
I would also like to know what kind of things I can do to my 250R to make it faster. Bottom end, midrange, topend (everything can apply) List away Please! Any tricks, or tips would be cool, think up some good ones. I know some of you have some good HP secrets. .............. I heard something about a CR250 reed cage will work in a TRX bike,is that true? What year works?

 

ill list a couple for you. better air filter,new bore job, better reeds, bigger carb, better exhaust. get rid of air box lid, try bigger front sprocket. Getting engine ported would be first on my list my porting cost around 500. get a different head a good one is torqueline. hows that? once you start modifying youll never stop and never have enough money.

 

I agree with atc86r. His info is spot-on. The easiest way to make your bike have more torque, or more top speed, is the gearing. Drop a tooth on your front, more low end. Go higher, more top end. I think that a pipe and filter is just about the most common way to gain power though. An FMF(cheapest, not best) pipe will give it more power all the way through, but lacks in low-end. Also, K&N is the best air filter you can buy. I run UNI, only because I race MX, and cleaning a foam filter is easier than a paper unit. Also, on the reeds. I'm pretty sure you can just go ahead and get a 250R reed for the same price. I believe Boyesen makes the best, but I'm running a Hy-Tech.

About the spark plug, I recently learned that during colder weather, Clymer recommends running NGK BR8ES, and in warmer weather, the BR9ES. Also, NGK's come Pre-Gapped. Good Luck,

 

LSB you're lucky I have never in my life gotten an NGK spark plug that was set to the right gap, they have always been to big a gap, I run 71 thousands and the plugs are like 90 something when I get them.

 

One thing that I do not see above is suspention parts. I would suggest getting Some shocks before you go into the engine. And if you are not planning on rideing mostly woods or tight places you might want to look at getting some a-arms and axel at the same time as shocks.

 

Sorry Killer250R, I don't know why you haven't gotten any! Mine have always been just right. I had to gap my Splitfires, and they still ran like crap!

 

Everyone is busy telling this poor guy what he need for his quad, and no one asked him what kind of riding he does. Decide what kind of riding you'll be doing the most, and let us know. Many of the things you can do to your engine are specific to the type of riding you do. Buy the wrong part for your application, and you're going backwards.

2-stroke engines are very dynamic, that is, every component has a large effect on the next. Change 1 thing and your entire engine is effected. Whatever you do, don't start buying a bunch of bolt on crap and slapping it on your engine. The only thing you'll end up with is a engine that doesn't run as well as it should, and an empty wallet. Do the right mods/upgrades in the right order, you'll spend less and a much better running engine. I see it every day, and most people are pretty disappointed when all their bolt-on goodies end up sitting on the shelf, or in the trash. Do it right the first time.

With all that said, BY FAR the most bang for your buck is a GOOD pipe. Anyone that tells you different doesn't have a GOOD pipe. The first thing to do is make sure your top end is in good shape, and then get a good pipe. The next thing to do is get the right carb. Bigger isn't always better, too. If you ride mx/woods/trails, you typically wouldn't want anything bigger than a 36mm. If you're riding a lot of dunes or wide open stuff, a 38mm is a great way to go. Once you're "bored" with those things, you can port your cylinder, go with a bigger bore, cr ignitions are REALY nice, as are all the "look cool" parts that are simply irresistable! Unless you're made our of money, a little bit at a time is a good (and fun) way to do it. You'll learn a LOT more in the process, too.

OK, I'm down off my soapbox now....

-doug