Jump to content


  • Content Count

  • Joined

  • Last visited

About Polar_Bus

  • Rank
    TT Titanium Member

Profile Information

  • Gender
  • Location
    New Hampshire
  • Interests
    Anything involving dirt, snow and speed.

Recent Profile Visitors

352 profile views
  1. Polar_Bus

    No low end power after changing piston

    Stamped arrow on the piston crown is pointing towards the exhaust port which indicates correct orientation. However you made me realize those look like aftermarket piston p/n's , now i'm wondering if the piston is the wrong size..
  2. Polar_Bus

    Yz125 running extremely hot :(

    First off you need to help us and give a better description of the basic issue. "my bike all of a sudden runs hot what's wrong with it" doesn't help us. We are not looking at your bike we are looking at a computer screen. First check all the BASICS. Is the coolant full ? Is the radiator clean and not clogged with mud ? Any wet spots around the engine ? Did you possible overheat the engine by too much slow speed riding in mud ? You might have a blown head oring.
  3. Polar_Bus

    No low end power after changing piston

    After reading your issue the one fact is clear the engine behavior changed after only a new piston. It's pretty hard to incorrectly assemble the PV linkage, and beyond verifying that the PV's slide freely within the cyl that pretty much rules out PV issues. I'm thinking there is nothing wrong with your engine, i'm actually thinking you had a very worn out top end, and now that you have a fresh piston you have 100% full power. It's extremly hard for us to help as we are only looking at a computer screen and not actually able to ride your bike and listen/feel the power delivery. Do you have a buddy that is 250cc experienced ? Does the low end power seem slow to accelerate ? Is there a flat spot in the acceleration then hits hard immediately ? There might be some debris clogging the pilot jet, I suggest a carb clean to rule this out...
  4. Polar_Bus

    Which style jets?

    An excellent online source for every jet out there: http://www.pjmotorsports.com/
  5. Polar_Bus


    Simple advice, and please listen carefully because your EXACT scenario has played out here on TT hundreds of times and it always ends up with the unknowing buyer getting screwed. 2S rule of thumb when a buyer claims and easy fix such as "it only needs a carb clean" or "it only needs a spark plug" or "it only needs ###### " you the vigalant buyer needs to assume that will end up as a $800 total engine rebuild. So ALWAYS remember this when you search for a 2s...
  6. IMO you're just running circles chasing your tail. You need to first isolate weather you have a fuel supply issue or a spark related issue. First question did this engine ever run 100% ? Did all the issues start immediately after the rebuild ? Lastly what exactly does the comment: "Have had jetting at every different combo" mean ?
  7. Polar_Bus

    Cleaning pistons

    Too much information. As for cleaning piston crown carbon, use Easy Off oven cleaner.
  8. Polar_Bus

    best smelling 2 stroke oil?

    Another vote for Klotz R50 , my preferred lubricant for the past 20 years. Smells just like Cam II race fuel
  9. Polar_Bus

    Slow but steady re-birth of my 05 250

    Gotta' give credit, looks awesome , I love it when guys restore clapped out bikes to as new condition. Prooves the point you don't need a 2013+ year bike to be competitive and have fun.
  10. Not to be a smarta$$ but if you are smart enough to have the elevated 2s knowledge skillset to do your own porting, you should not have to ask on the internet "which top end pipe is the best" you should already know the answer.....
  11. Polar_Bus

    To Port or Not To Port.......

    Keep in mind, added hp is USELESS if you can't 100% efficiently use what you alrerady have.... Added hp in many cases actually results in SLOWER lap times resulting from excessive wheelspin, and elevated rider fatigue. Adding 5 hp to a MX 2 stroke with poring alone is impressive on paper, but putting the added 5hp to efficient use into the dirt is another... In my experiences sometimes replacing a worn out rear tire is equivilant to adding 5hp....
  12. You need to isolate weather you have a fuel supply issue, spark issue, or compression issue. FIRST step I recommend as always is do a cmopression test. If you have worn top end you could be loosing compression as the engine gets hot, loosing combustion. Another simple test is once the bike dies, immediately pull the plug and check for spark.
  13. Polar_Bus

    Grease fittings on the swing arm?

    This seems to be a great idea, and admittedly I've though of the same modifications. My thoughts are however that by design, I don't think the grease would be able to be forced into all the bearing and bushing surfaces. The most common siezure point in the S/A linkage system is the inner sleeve to bolt clearence. Even utilizing zerks, I don't think the grease would get to this area. I also though about "cross drilling" the sleeves but they are hardened steel and you can't drill them (well not drill them with traditional drill bits you can drill hardened steel with solid carbide, but those drill bits are HUGE money).
  14. Polar_Bus

    What to do with "old" mixed gas

    Old questionable fuel is for chainsaws, weed wackers, or camp fire propellant. It's NOT worth the risk running it through your expensive YZ...
  15. Polar_Bus

    Blown up 02 yz125

    No such truth. Knowing the good market for YZ125's assuming the engine would need a complete bebuild (and I guarantee it will), and assuming you are mechanically capable of doing the labor yourself, I would be comfortable offering $300ish for that bike IF all the other chassis parts are in good shape. Protecting your best interest, make sure you have a CLOSE look at that bike before you spend, it's far too easy to get excited about a cheap wonderfull winter YZ125 "bike restoration" , than the more likely scenario of a winter "bike restoration money pit"....