Need some advice on my 2002 yz250f

[hod928]

Hey guys i just bought a 2002 yz250f this late fall. I only got about 4-5 weeks of riding it until the good old Michigan winter set in. The guy i bought the bike from was the Original Owner. He has never rebuilt the top end, had the valves shimmed or anything like that. My plan is to race the bike this spring. I'm wondering what should i do to get the bike more race ready. I'm thinking i should put it a new High Compression Wiseco Piston, and i did notice that the break pads were very worn down so that was also in my list. So what else should i do to get my bike more race ready for this 09 season.

Thanks

 

[IndyMX]

Do the valves...

A 6 year old 4 stroke that's never had the valves done, is a bike waiting to break.

 

[Matt90GT]

Start like any race bike. Tear it down to the frame! Like said rebuild the motor with new piston and valves. Crank would be check while you are there if you are going to run a hi- comp piston. Run the 13.5:1 and also update the exhaust cam to the 2003+ style with the autodecompression.

After that every bearing in the bike needs to be inspected.

Suspension - rebuild and revalve and respring for your weight and ability

Brakes, install new pads.

New chain and sprockets

New Tubes and tires.

That should get you in the ready.

 

[IndyMX]

I'd even consider new brake lines, but at minimum you should flush the lines and replace the fluid. You should be doing that at least once a season at minimum anyway.

 

[slodad]

Don't be too alarmed by the valve comments. How and how much did the original owner ride? If he didn't race and was conscientious about cleaning the air filter and changing the oil, the head is probably fine. Many of the YZFs get hundreds of hours out of a set of valves. They are noted for their reliability, compared to the other Japanese makes.

Consider spending some money on getting the forks revalved. Stock, they can be a bit harsh compared to newer bikes. I don't go very fast, but I sent mine to Smart Performance for some attention and am pleased with how they turned out. My awkward landings are much more comfortable now.

 

[hod928]

Yeah, im not to worried about the valves. But like IndyMX said its been 6 years since anyone has seen them. It might be good to have them looked at. The bike i think rips for being mostly stock. During the fall here riding on some tracks i was ripping past my buddy's who i think are better riders and they also have newer bikes then me. I'm going to take my bike to a shop and have them look at it while its still winter and i dont gotta worry about taking some riding time away.

As for the exhaust cam would you recommend putting an intake cam on it also?? Ever since i got the bike i been thinking about putting in some hot cam's but whats the difference between Stage 1 and stage 2 hot cam's? There the same price for my bike but i cant find anything about the difference.

 

[hod928]

For the piston you said to run a 13.5:1 ive been looking for them and found a few on ebay and they say race only. Will i need to run racing gas with this piston? The only thing i run threw my bike is highest grade pump gas i think its 93? What would the difference be of i ran a 13.2:1 over a 13.5:1

 

[longtime coming]

I don't understand why so many are concerned with engine hop-ups when most engines could be "hopped-down" for most rider/mechanic combinations for better results. How do these guys race when relying on a shop for all their mechanical work? A properly set-up stock bike is the best for most, I think. BWDIKA? :laugh:

 

[hod928]

Famous last words from many a rider. ;)

haha yeah. Im deff going to go have them checked out gotta call some powershops around me and see what there gonna charge me. Most places anymore are 75-100$ an hour ><

 

[hod928]

yes

 

[Rich Rohrich]

haha yeah. Im deff going to go have them checked out gotta call some powershops around me and see what there gonna charge me. Most places anymore are 75-100$ an hour ><

Checking the valve clearance yourself is very easy. The service manual has the whole step by step procedure.