De-Smogging has no performance benefit that I know of. Doing it will let the entire exhaust system run lower temps.

 

There~in lies the problem and the solution. Get ahold of Bill Blue and fixer up. I would rather ride my 1975 XL 125 than a stock KLX 250.

 

Maximizing stock bore power is quick, cheap, and easy. Tearing down and replacing most of the top end with a big bore kit is always an option for a large leap in power.. I wish there was an easier incremental increase available.. Wonder what you get when you bolt in a set of webcams (101's) on a well set up stock bore ? It seems the 351 increases about 2hp with the 101's..

 

I already had the usual 351/FMF setup and, finally, got around to dropping in the TM36-68.

I literally just finished and was ridding it around the yard and street. All I can say is wow. Wow.

My initial impression is the TM36-68 carb makes about as much difference is the bore kit.

The bore kit powers up for sure, but it still feels tame. Add the TM to the mix and it turns into a tiger. The hit is just right there, all the time. It seems to bring the power the bore kit has instantly. Incredible.

It's nice that you can do the build in stages. The stock bike is tame and easy to ride if a new or returning rider. I'd advise riding this way for a couple of months just to get used to the bike and suspension.

Then add pipe and jet and/or bore kit. The bike will have a lot more pep and will power though stuff it couldn't before. Longer mud sections, talller hills, it'll pull top gear. It's stronger by quite a bit but not at all intimidating with the stock carb.

Add the Mikuni and you have a full on woods bike. Power right off the bottom or whereever else you want it.

This summer it's Race Tech valves for me, because the motor is done, as far as I am concerned.