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About mxracer41

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    TT Bronze Member

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    pitbikes, dirtbikes, racing, hockey
  1. mxracer41

    Tips for breaking in a new motor

    Yup, thats bascially what i did. Started up, warmed up completely and rode. Did that a few times and changed the oil then let her rip:). And to answer the question above, I am running a mix of race and pump because I have hot cams with altered timing (professional mechanic of previous owner did this) and I have a full fmf system as well. I know I probably don't need to but I am going to continue to do so because I ran the same setup on my old honda and that thing blew the rings out in about 5 hours when I didn't use race fuel. When I switched to half and half I never had another problem with it.
  2. mxracer41

    Eric Gorr

    Even more props to Eric: We sent my brothers KTM 85 cylinder to him after it blew the head off and stripped out all of the bolt holes, and he re-tapped all of them and didn't even charge a thing besides return shipping
  3. mxracer41

    Tips for breaking in a new motor

    Wow, after reading that article it's pretty interesting and it makes pretty good sense as well; it'll definently change the way I break in my motors from now on.. I rode the bike hard for the first time this weekend at the track and so far it is running great!! Hopefully it stays this way now because I am broke as hell after that rebuild.. lol. As for the fuel, I'm running a 50/50 mix of cam 2 and super, which seems to be working pretty well for me, so I think I'm gonna stick to that.
  4. mxracer41

    Changed Cam Chain And Found....

    Definently split cases and put in a new crank and crank bearings for sure... If you don;t wanna drop the extra $$ on OEM crank and bearings, Hot Rods makes very good replacements! Also, you can get a case splitter from Rocky Mountain for arouns $50-$70, and it will save you alot of pain and headaches!!!!
  5. mxracer41

    YZ250F Cam Chain

    Like said above, look up Johnnysshop video on youtube, it'll explain basically everything you need to know. Cam chain replacement is really easy! Have you ever gone into the top end of your motor before?
  6. Some of you may have already seen my thread about my bike blowing up back in October and breaking thousands of dollars of parts.. well anyways just got it all up and running again!!! Now I am just wondering: How long should I break this thing in for? Literally every single bearing in the bottom end is new, along with the cases, crank, cylinder, piston/rings, etc (Basically every part besides the trans countershaft, valves/head, and clutch.) Therefore, I know it's probably gonna take a little longer to break this thing in compared to your normal bottom end rebuild. I am also running Stage 2 and 3 hotcams as well as a full FMF 4.1 system. What kind of fuel should I run? Before the motor grenaded it was bored to a 270 along with the cams and pipe, so I ran straight race fuel (cam 2). Could I get away with mixing the fuel 1/2 super and 1/2 cam? Any input is appreciated! Also, bike is a 2010 YZ250F if it matters.
  7. mxracer41

    Good Parts source??

    It's #10 on the transmission schematic, the upper mainshaft bearing I believe. And I will definently try motosport, I completely forgot they sold oem. Powersports plus looks good, ill give them a shot too. Thanks!
  8. mxracer41

    Good Parts source??

    Does anyone know of a good place to get Yamaha parts from? I really want to get my 2010 motor rebuilt by friday/saturday but am missing one of my transmission bearings and can't put anything else together until I get it.. any suggestions? I am in MD by the way.
  9. mxracer41

    what year EFI CRF ?

    By the way, the bike only had about 53 hours and had oil and air filter changed every ride and oil filter changed every 3, so it was not a result of a lack of maintainence either..
  10. mxracer41

    what year EFI CRF ?

    By the way, the bike only had about 53 hours which oil and air filter changed every ride and oil filter changed every 3, so it wa snot lack of maintainence either.
  11. mxracer41

    what year EFI CRF ?

    DO NOT buy a 2010 honda unless you plan on replacing the crank right away. I just rebuilt a 2010 250R for my buddy, his crank rod bearings locked and broke off completely in his motor. It broke his cases, piston, crank, etc, so I also had to replace every bearing in the main cases as well, so parts bill totaled up to almost $1300, which is pretty ridiculous. Just a word or warning
  12. mxracer41

    yz125 problems

    Definently put a top end in it, 60PSI is wayy low.. as long as the cylinder looks good and everything and crank is in good shape throw out $110-$120 for a top end kit and you'll be good to go
  13. mxracer41

    YZ250F not starting!

    ^^^^ What he said. Make sure EVERYTHING is right before you keep riding that thing or it will eventually grenade on you.. I've had it happen to me a few times and it ended up costing me a wholeee lot more than I coulda fixed it fo rin the first place. Also for future reference, if you have no spark, check the plug and unplug the kill switch first. If its neither, it is more than likely your stator. The coil and CDI rarely ever go bad, you really shoulda tested before you bought them but oh well... what did you weld on the head??
  14. mxracer41

    YZ250F valve question..

    Wow you know I did not know that honestly... well that explains it then. Id be willing to bet that because of that reduced spring pressure the valve(s) floated and caused it to smash into the piston... wow. I guess Ill be having a talk with the mechanic then!
  15. mxracer41

    YZ250F valve question..

    Yup the head is done for, by time I pay to fix it I could buy a new one on ebay for $390. I'm gonna mic the shims and see how much material he took off. It had to be a substantial amount because the valves were almost zeroed when I brought it to him..