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Roger M

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Everything posted by Roger M

  1. Roger M

    Question about repairing an air filter.

    Don't use gas! Clean your filter with kerosene to strip most of the oil, then wash it in very warm water and laundry detergent to get out any remaining dirt. Even if you have to re-glue some areas after cleaning the filter, the important thing is that the foam is sealed to the rubber ring when the filter is re-installed in the airbox. It's not a perfect solution, but it beats buying new filters all the time.
  2. Roger M

    motor oil

    Use Honda HP4M in hte crankcase, and GN4 in the tranny--both 10-40W. Overfill the tranny slightly to 825-850cc.
  3. Roger M

    Improved Horsepower

    Forget all this with the cams---the stock X cam is best for valve life--if you want more power EVERYWHERE and all you can handle, get a high compression piston and run VP U4.4 oxygenated race fuel.
  4. Roger M

    Suspension Linkage Bearings

    My advice would be to stick with the OEM parts. They may cost more, but they are top quality. Find a dealer, online or otherwise who will cut you a break on the price. Don't go for cut-rate with bearings--that's for plastic and other non-critical stuff.
  5. Roger M

    Big Bore vs High Comp Piston

    I've not used a big-bore set-up, but for racing applications, I have used the JE high compression piston for 3-1/2 years and am very pleased with it. It provides a nice boost everywhere and still allows the engine to rev-out like stock with proper jetting and air-box mods. I don't scream it--don't have to--she runs like a scalded-dog. I also use oxygenated race fuel which isn't necessary with the HC piston, but the two seem to go together really well.
  6. Roger M

    Rear Sprocket for Hare Scrambles

    I prefer the stock, which is 53, if using a knobby--they tend to slide and spin some. If using a trials tire, a 54 works better--makes 2nd gear a bit more usable in tight woods sections.
  7. Roger M

    Question about repairing an air filter.

    This happens to the OEM filters, usually about the 3rd time its cleaned, no matter what oil or cleaner is used. I have several, and have repaired them all with Shoe Goo from Wal-Mart. It works reasonably well if you make sure the filter is totally clean of any oil and completely dry before applying the glue. Allow the glue to set for at least 24 hours before using the filter. If done properly, it generally doesn't come apart in the same place again.
  8. Roger M

    Gearing down a CRF250X

    You can use a larger rear sprocket than stock without issues with the chain guide if you add 1 link to the chain--this moves the axle back enough to provide clearance. I am currently using a 54 rear, which is available from Honda. Note that a 14 tooth front sprocket is the largest that will go on and clear the swingarm.
  9. Roger M


    I think for your weight, which is about the same as mine, these settings will be harsh unless you ride very aggressively. With the stock valving, I would soften the fork compression 3-4 clicks, soften the shock hi and low compression by about 1/2, and I would use the stock fork springs which are .42 and go to a 5.0 shock spring or at most a 5.2
  10. Roger M

    04 CRF250X acceleration problems

    One other thing--check that the vent in the gas tank cap is not clogged--that would cause it to behave in a similiar fashion to what you describe after a few minutes of running normally.
  11. Roger M

    04 CRF250X acceleration problems

    The wiring to the clutch lever only involves the starter motor, not the ignition--my guess is the problem occurs when load is applied to the engine and pulling in the clutch relieves the load. I would check your carb's accelerator pump for proper function--with the carb off the bike, a significant squirt of fuel should be immediately visible from the AP nozzle in the carb throat when the throttle is twisted. If not, flush-out the tiny passages in the AP cover and up in the body of the carb with carb cleaner and compressed air, and examine the pump diaphram for signs of damage. Also, if you don't have the "O-ring modification" to the AP link lever, you should do so--the extra force from the o-ring makes a huge improvement in accererator pump function. It wouldn't hurt to double-check your valve clearances, and give your ignition wiring a once-over looking for loose connections--maybe check the kill-switch wiring for shorts against the handle-bar and steering-head.
  12. Roger M

    Accelerator pump issue

    Make sure all the little holes in the AP cover are unrestricted by dirt/debris--blow through with carb cleaner and compressed air. Also check the passages in the body of the carb that lead to the AP nozzle. Not too likely any problem with the diaphram, but I did have one become sortof curled-up, so I replaced it. My AP became non-functional for reasons still undetermined, but the O-ring modification to the link-lever corrected the problem and made it work better than ever.
  13. Roger M

    FMF silencer

    The Powercore is about the same as stock but with a bit more pleasant tone to it--I use it racing hare scrambles without any issues. If you are using a powerbomb header, that might bring the sound level down some.
  14. Roger M

    What fork oil level do you run?

    Fork fluid level doesn't have any impact on fork action until you reach the last couple of inches of travel--at that point, the change in fluid volume produces a change in air-spring effect. Adjust your compression clickers to a softer setting--when I went to stiffer fork springs I had to go down to 6-8 clicks from full soft. Roger M--04 X
  15. Roger M

    OEM or aftermarket fork seals

    Use OEM--they're the best. I've heard of many situations where other brands didn't hold up or leaked right-off. One of mine on my 04 is actually the original one that came on the bike and it doesn't leak significantly after 4 seasons racing--you can't beat that kind of durability.
  16. Roger M

    Anybody running a trials tire?

    I'm on the verge of trying one--I've seen some guys using those tires motor-up obstacles that you would'nt believe with ease. They appear to offer great traction over roots, rocks, and hard-pack, even hard-pack with an inch or two of slime on top, but in deep mud they're at a disadvantage to a full-on knobby. The biggest draw-back is because of the extreme flexibility of the sidewall and the low pressures used (6 to 8 psi), flats are a very real risk. You need to use extra thick tubes (4 to 6 mm) and tires with 6 ply sidewalls. They're also quite expensive tires but do wear much slower than a knobby.
  17. Roger M

    Seat identification 04 250X

    The stock springs can be recognized by paint markings which are different colored for intake vs exhaust--I don't see any paint on the spring pictured. If you're using Ferrera valves then I would use their springs also, but if the seats are badly worn then it might be best to go with a new head and new valves and springs. The seats can usually only be recut once--if more material than that is removed then too much has to be shaved off the end of the valve stem in order to get correct clearance.
  18. The usual clacking noise from my valves on my 04 X seemed to be gradually getting more pronounced for some time, but when I recently installed a re-condtioned spare head, the noise got MUCH worse. The head had been re-worked with new guides, seats cut, and new stock valves/springs/hardware. The only parts not replaced were the cam, buckets, rockerarm and it's pivot pin. Clearances were correctly shimmed to spec. I'm wondering if wear on the cam bearings or on the exhaust rocker/ pivot pin would account for this problem. The Honda service manual doesn't give a very exact method for evaluating the cam bearings--only that they spin smoothly and aren't loose on the cam. Would appreciate input from engine builders and anyone experiencing similiar valve noise.
  19. Didn't change the cam, so the decompressor wasn't removed. I think I've found the problem--must have gotten the cam bearing clamps swapped to the wrong head--apparently the clamps are machined to fit just so on that particular head. I swapped them and the valve "tick" is way reduced. That must be why Honda supplies the clamps with a replacement head.
  20. Roger M

    SS valves,how long will they last?

    Generally quoted "rule of thumb" is 2 to 3 times the lifespan you would have gotten with the stock titanium. I was getting 45 hours with the Ti valves, now have 100 hours on Ferrera stainless intakes, but they have required shimming once at about 50 hours.
  21. Roger M

    SS valves,how long will they last?

    Anyone have advice on when to rebuild the crank?
  22. Roger M

    CRF250x - closed circuit mods

    You can change the main jet without removing the carb, but pilot jet or anything else its best to remove the carb IMO. Its not all that difficult. Take off the exhaust system and the shock, then loosen the carb airboot clamp and swing up the sub-frame, unthread the hot-start cable/plunger and the carb can be pulled back to allow access to the throttle drum to remove the cables, after doing that the carb is free. Those are the major steps, leaving out the smaller details since you're saying you've had the carb off once before.
  23. Roger M

    Another x race mods thread

    If you haven't opened-up your airbox and richened-up the jetting, you will want to do that in order to take advantage of the increased flow potential of the PowerCore exhaust--JD jetting kit with o-ring mod for the accelerator pump linkage is a good way to do it. Without going into the engine, you could add a Boyseen QuickShot accelerator pump cover and a PowerNow intake wing--both will give more boost. Other than that, you might consider running oxygenated race gas, such as VP's U4.2 (or MS109 if you need to use unleaded), which works well to increase the response and power of the CRF engines. Richer jetting is required with oxygenated fuels. When its time for a new piston, put in a JE high compression--13.5 to 1 vs. stock 12.9 to 1. You might also eventually want to use an R cam for moto--the 05 R cam gets good reviews for increasing boost without too much sacrifice of low rpm torque. Not sure what to advise for tires, where I ride we got more mud than hardpack.
  24. Roger M

    Attaching the Airbox Boot

    The process is easier when the shock is removed--I always have the shock and the exhaust system off when working on the carb anyway. I would be careful with the grease--you don't want any to clog the tiny air jets on the back of the carb where the air boot attaches.
  25. Roger M

    Bike Troubles 2005 CRF250X

    Electrical problems are rare on these bikes--unless you've got a pinched wire somehow, my guess is you've still got a fuel issue, check to be sure there is fuel in the carb float bowl when the engine stalls (could be a sticking float valve or maybe even a plugged tank cap vent)--the next most likely thing is intake valve clearances.