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About mtchristman

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  1. mtchristman

    05 KX250F Jetting Start Point

    I'm still waiting on Kibblewhite intake valves. I did dig into the carb and it has a 40 pilot and a 178 main to begin with. Don't I need to move to a bigger main jet also? Thanks again.
  2. mtchristman

    05 KX250F Jetting Start Point

    Leave the fuel screw where it's at? Thanks.
  3. I have an 05 KX250F that is getting rebuilt. The motor should be finished up in the next couple of weeks. The bore will be stock, but I've had the head ported, added hot cams, a uni filter, a pro circuit pipe and header. I haven't changed anything on the carb since I got it. Any ideas on a starting point for jetting. I have a Sudoco catalog so getting jets or needles is not a problem. Just where do I start? Thanks ahead of time.
  4. mtchristman

    New Valve Seats

    Anybody try the pro circuit valves and springs? I can get their stuff at dealer cost.
  5. mtchristman

    New Valve Seats

    Rebuild time for the 05 KX250F. I'm putting a new piston in and going to have the head worked over. I had problems with the left intake valve tightening up. Are you guys replacing the head and starting fresh or are you replacing the seats. If you are replacing the seats, where are you getting them from and what kind are you using? My shop at home will put them in and guarantee their work, their just not sure where to get them at. I also plan on putting a kibblewhite kit in, but can't find a part number for parts unlimited or tucker rocky. The 06 books won't be out for awhile yet. Does anybody have a part number for Kibblewhite stainless valves, springs, retainers and buckets. This is for an 05 KX250F. Anything I'm missing or better ideas for the head let me know. Thanks.
  6. mtchristman

    The dreaded left intake valve! 05 Report

    I figure at a minimum I will put a wiseco piston in it, no matter how good the stock piston looks.
  7. mtchristman

    The dreaded left intake valve! 05 Report

    Have you had to replace the piston in one of your bikes yet? How did the cylinder look?
  8. mtchristman

    The dreaded left intake valve! 05 Report

    I picked up my sons 05 250F new last september. It's been through 20 races or 40 heats, 20 pre race practices and lots of practice time this year. All races were in the begginner class and the bike got him a first overall in his class. He is pretty happy for his first year racing. He will start C-class next year. I use kawi brand 10-40 oil non-synthetic. We change the oil after every race and the oil filter every other race. The bike is completely stock besides an aftermarket chain and uni filter. Anybody who owns one will know the stock chain is junk an never stops stretching. The stock handlebars are flimsy, but even after all the wrecks he has had, they have made it the whole season. I plan on getting some aftermarket bars for next year. The stock air filter just wore out quickly from cleaning and I like uni filters. Even switching to the uni the jetting has been spot on. I could have probably tweaked the jetting a little on a couple of our 100+ degree race days, but didn't. We've been cleaning the air filter after every race. I've always been a dunlop man, but the bridgestone tires that came on the kawi have worn like iron. In hindsight I probably should have replaced the rear with 4 or 5 races left, but made it the whole season on the one tire. I will be putting another bridgestone tire on. We first checked the valves after 10 to 12 hours and had to reshim all four valves. I also lost a shim. We pulled the motor and washed it out with solvent, ran a magnet in and over every nook and cranny and never found it. Another 6 or 8 races later I took it to our local shop to have them check the valve clearance (I was pressed for time or I would have done it myself). When they pulled the valve cover they found my missing shim. Who knows where that damn thing was hiding at. It had been bouncing around on the exhaust cam and the cam was chipped up pretty good so we replaced it. The valve clearance was still spot on. Another 4 or 5 races later the intake cam seized up during practice. The shop tightened up the cam journals by the manual and hadn't gotten the service bulletin about over tightening the journals. The owner of the shop is a good friend, our sons race together, we ride to the races together and he takes good care of me on parts. By this time we only had 4 races left and I was really hoping to get through these before doing a total rebuild. He plasti-gauged the journals and seized cam and was able to hand lap the journals and cam back to spec. The bike ran good the first race after the seized cam was fixed. It didn't have much compression the second race and we had to push start it both heats. I checked the valve clearance and the left intake was so tight I couldn't get any feeler gauge in at all. I shimmed it back up hoping for the best for our last 2 races. The bike started up fine and ran good for the last 2 races. After the last race the compression was gone again. Opened her up and the left intake was tight again. The exhaust side is still in spec. I'm not gonna push my luck any further. I was planning on a total rebuild this winter anyway and I'm pretty happy we managed to get through the whole season and only had to buy an exhaust cam. I plan on getting a new head and going the kibblewhite route. What have you guys been doing on new pistons? Are you just checking the cylinder and if it is in spec just putting a new piston in? Anybody replating their cylinder or just buying a new one? Anybody had any problems with the bottom end or are you just rebuilding the top? Overall I've been really happy with this bike and I will buy an 07 when they come out. I think I've taken pretty good care of this bike and I'm looking forward to another season on it. I do think there is a problem with the left intake valve and it will probably be just a matter of time before it pops up for everybody. Keep a close eye on the valves and just plan on replacing them as part of your maintenance and you should be good to go.
  9. mtchristman

    Oil Filter Q?

    Reversible needle nose pliers work wonders for getting the filter out.
  10. mtchristman

    315 big bore, any reviews?

    What channel and time?
  11. mtchristman

    Valve Feeler Gage

    I would also suggest a good automotive type magnet for putting new shims in.
  12. mtchristman

    How to change a KX 250f Transmission oil

    Yes, remove both bolts when you change your oil. The smaller one lets the oil out of the tranny. The kawi doesn't have seperate tranny oil.
  13. mtchristman

    CRF250 vs. RMZ250

    I've ridden all three and own an 05 KX250F. To me the yamaha seemed to have the most topend and you had to keep it screaming to get the power to the ground. The kawi seems to have the best midrange and bottom end and it seems like it does a good job if you keep it there and short shift rather than screaming it to the moon. The honda didn't seem to have much bottom to it, but the midrange was somewhat close to the kawi, the topend is better than the kawi but nothing like the yamaha, plus with the honda you can ride it in the midrange like the kawi. To me the honda had the best suspension and a click or two on the clickers and you could feel the change. It's a coin toss to me for the yamaha or kawi being next. The yamaha seemed more stiff and the kawi seems to be more soft. More of a who's riding it than anything. It seemed like the honda could be adjusted either way. The kawi seems to take huge adjustments to get the suspension to do anything. I couldn't beat the price on the kawi, so that was the decision maker for me. All of these bikes are very good and all have there plus's and minus's. You will probably be happy with any of them. On a side note at our first race this year the kawi pulled a massive holeshot both heats.
  14. mtchristman

    how to tell if valves are out of spec

    The initial investment is more expensive if you do it yourself, but will pay off in the long run. A Hotcams shim kit will run you $85 or you can buy the individual shims for $5 to $8. A good inch/lbs torque wrench, You can pick up snap-on's on e-bay for $150. Feeler gauges $5 to $10. A magnet to put the shims in. You can figure out what your local shop charges against doing it yourself 4 or 5 times in a row. The manual that you download is an 04 manual and says to use 104 inch/lbs on the cam cap bolts, the gurus on here say to use anywhere from 82 to 88 inch/lbs. The manual does a good job of explaining how to check and adjust the shims otherwise.