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About nitro201

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  1. I change my air filter after every ride and this motor has less than 5 hours since last rebuilt, which I was told. But I noticed this motor had the same wear marks as it did on the last cylinder, which came with this engine. Thanks
  2. Hello everyone! I would like to find out more info since, I'm not getting it from my mechanic. What causes scaring on the intake cylinder wall on Yamaha YZ426 motor? My crank was off by .010 so my mechanic trued the crank back to .001 . Would this cause my motor to run very hot and cause my piston hit the cylinder wall on the intake side? Has anyone else experience this same problem Please let me know YZ426 motor if this helps
  3. nitro201

    oil leak

    The oil is leaking out of the decompression above the header pipe, maybe missing the o-ring or copper washer
  4. nitro201


    How much for the motor?
  5. Yes last time I took my head and cylinder off, the cylinder was warped a bit and the machine shop had to mill the surface like 5 or 10 thousands because of the motor getting hot. But since I had a bad head gasket I think this is reason why my cylinder was scored. I just want to make sure I get all of bugs figured out this time. No water so far in my oil or oil in my water but it was burning antifreeze and coming out of my tailpipe. So I checked my motor while it was running and found I had a leaking head gasket so I shut the motor down. I have YZ400 lower bottom end but a YZ426 crank, piston and cylinder so this makes it a 426 but just using the lower half like gears, clutch, cases and etc... from a yz400 thanks
  6. I race quads and this motor never idles except on the line. The antifreeze spits out fluid when I get on it half to 3/4 throttle.
  7. Thanks for all the replies but my cylinder is wearing pretty bad and looks like the oil pump might be bad.
  8. I have a YZ400 bottom end which has a YZ426 Crank, piston, clyinder and head. I've had nothing but problems with this motor overheating from day one. I've replaced the waterpump seals, shaft, bearing, radiator cap and added Engine Ice, filled my coolant one inch below neck. I've blown 2 base gasket and 1 head gasket. I have also tried two different radiator's added a overflow bottle and still overheating. My cylinder on the backside is wearing pretty back so could this motor be getting hot b/c of the oil pump and cause me to blow base, head gasket and then spit out antifreeze. Something is wrong! PLEASE HELP IF ANYONE HAS ANY INFO......THANKS
  9. nitro201

    Indoor Tracks In Northwest Ohio?

    At Hotrods they change the track ever other weekend but I still like Earlywines but I also race quads. By far one of the best motocross outdoor tracks in Ohio is COCR which is in District 11. (2hours from Wilimington and they also have harescrambles)
  10. nitro201

    Indoor Tracks In Northwest Ohio?

    Checkout this place for Indoor MX http://webpages.charter.net/hotrods/ It's only $25.00 and 1 hour from Wilimgton Oh
  11. nitro201

    cleaning old plugs

    My mechanic uses the sandblaster to clean my plugs and works just fine from one race to the next..
  12. nitro201

    02 426 wont idle

    I had to adjust my pilot jet.
  13. nitro201

    Yz Motor Problems

    So every time you guys race the YZ426 motor's you have to top off the radiator because of the antifreeze expanding that much? My antifreeze level was down almost 2" from the top of this radiator I'm running and it's a double row radiator with inline coolers. It probably holds approx 1/2 of a gallon, if not more. But what's the real reason for it expanding through the weep hole? Instead through the overflow. My radiator cap that I'm using is 16psi. ... Stock YZ opening pressure is 13.5-17.8psi.... I know these radiator caps have worked on other YZ motor's in the past.. Thanks again guys I know we're going to figure this thing out sooner rather than later! I can tell you one thing this motor is very strong and can't wait to get this problem fixed because I'm going to kick some a$$ on this machine this year... I see everyone point on the condensation most likely getting in my breather or from excess antifreeze at one time.
  14. nitro201

    Yz Motor Problems

    I did replace the head gasket the same time as I did with the base. I guess my problem might be the Honda TRX250R radiator cap. What's the PSI rating on the stock YZ400 or YZ426 radiator cap?? If it's my radiator cap would you still do a leak-down test to make sure the gaskets or seals did not burst again because of the pressure. Thanks for all the help!
  15. nitro201

    426 cooling ???

    Quaddad, What radiator cap are u running? Aftermarket 250r or stock?