adding some punch to an 03 150

I would like to increase performance without increasing displacement. Thinking high compressioon piston and cam but wiseco dosen't list either for this bike. Also find the frontend to be too soft, Thinking of spacers to increase spring preload. Any suggestions??:busted:

I would like to increase performance without increasing displacement. Thinking high compressioon piston and cam but wiseco dosen't list either for this bike. Also find the frontend to be too soft, Thinking of spacers to increase spring preload. Any suggestions??:busted:

Have you pulled the baffle out of the exhaust and the snorkel out of the top of the air box along with rejetting the carb? That alone gives a noticeable increase in performance.

As far as spacers a lot of people use stainless steel washers, I was using 10 washers in each fork but recently installed the Racetech fork emulators.

Thanks for the advise. Ordered the jets and am also thinking of removing the spark arrester. Since we will be running on short tracks I dont think there is much concern with starting a forrest fire. What do you think of using PVC pipe with endcaps as fork spring spacers. I'm thinking it may be strong enough and easily adjustable. On that note...my local Honda dealer was unable to tell me which or how much oil to use in the forks...the spec sheet just said "NA" are they gas filled. I was thinking of stepping the oil weight up a bit.

I'm pretty sure I remember reading somewhere that the spark arrestor should be left in to supply a little bit of back pressure to the engine. If you are looking to get a little more power by changing the exhaust, but don't want to spend the money on a whole exhaust system, check out the Powroll Thrust Chamber for about $60. As far as fork oil...read THIS post...:busted:

Thanks again. Expect your are correct about retaining some back pressure. The thread answered my fork questions as well. Will be converting it into a flat tracker...stay tuned I'll let you know if it's competitive...

Your going to need to do something with the shock if you want to flat track it. Hlebo Suspension can revalve the stocker or get a works shock.

Lots of 150's and 230"s out here in CA running dirt track.

Expect you are right. For now I just redrilled the lower clevis to reduce height and set the spring preload up a lot. If it's competitive and fun, I'll probably get further into it. Although my eng game will probably to set up and run a vintage 500. Thanks for the advise.

You need a little more rebound dampening so the thing doesn't kick you off.

Thanks again. Expect your are correct about retaining some back pressure. The thread answered my fork questions as well. Will be converting it into a flat tracker...stay tuned I'll let you know if it's competitive...

A friend and I are both running pre-05 Honda 150F flattrackers. Using Dunlop K180 front and Bridgestone dual-sport rears, on stock rims, stock suspension. I only weigh about 145, so I'm happy with stock fork. If I drive it into the corner, it squats and loads the front good. If I weighed more, I would consider something else though. Haven't had any problems with rebound on the rear, both of us have added pre-load. We're running mostly short tracks, often dry-slick, and/or rough. Some guys are running 17's with soft compound Maxxis and they are a little of an advantage on blue-groove. The 150F is heavier than a lot of other bikes in the class, but the full size frame makes it handle better. There is a LOT of potential in the motor too, depending on the rules. For motor options, shoot coeshow a PM.

I don't get on the forum very often, if you need any info though, shoot me a PM.

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