2 stroke fun for 200 bucks

Discussion in '2 smokers' started by hardwaregrrl, Feb 16, 2011.

  1. PFFOG

    PFFOG Richard Alps-aholic Supporter

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    if the piston clearance was too tight, that will cause seizure as well. the piston should fall through the bore (with no rings on) if you have to push it through, it is too tight. After boring hundreds of these, using an ammco precision hone in a parts cleaner, I found my feel to be as accurate and a micrometer and snap gauge, for checking clearance.
  2. hardwaregrrl

    hardwaregrrl Can't shoot straight Supporter

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    Well....we live and learn. Right? I figured I owed you guys an explaination. I took the cylinder and piston back to MSP. And looking at it in compairison to the original piston, it's the same seizure. I have an airleak....:bluduh And it's my own damn fault....well, not really. Oh, and by the way, I didn't really figure this out on my own...:D MSP pretty much told me...and they really are awsome to work with as my little bike had been a topic at the shop for a bit. So, I think they're going to try an source a cheaper piston or let me try...which is pretty damn cool. So a big "thanks" to MSP.

    Anyway, I was checking the jets as they are not labled on my carb. I need to go up a main jet size for the boring increase. But none were labled...but I did find that a screw was missing...:shog

    <a href="https://hardwaregrrl.smugmug.com/Motorcycles/projects/16004530_tuE5K#1216530562_yBaZ7-A-LB" title="Photo & Video Sharing by SmugMug"><img src="https://hardwaregrrl.smugmug.com/Motorcycles/projects/P1050248/1216530562_yBaZ7-M-1.jpg" title="Photo & Video Sharing by SmugMug" alt="Photo & Video Sharing by SmugMug"></a>

    So, just trying to figure out the pilot jet size and see if I can squeeze it onto my bike bandit order. Maybe another week or so till I get everything back. I really hope that is the air leak and not the right crank seal. Rod told me to fill up the head with air to find the air leak, but I cannot fathom that being possible.:dunno
  3. Al Tuna

    Al Tuna NSFW

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    you got's to split the the case sweet pea! Them seals are old:zilla
  4. bgoodsoil

    bgoodsoil Dare to be Stupid

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    Is there a difference between an air leak coming from the intake like that and the bottom end? Is the danger of the crankseal air leak due to it drawing from the bottom or something?

    I've never heard of leak testing a crank case though I guess it possible? Anybody know anything about that?

    Gimme a call if you separate the cases. I've never done it and I'd like to see what's involved. Got any free time next week?
  5. Grider Pirate

    Grider Pirate Long timer

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    Any air leak is bad. A leaky seal on the right side should be super obvious, since there be oil on the outside of that one. It would smoke to high heaven.
    A gazillion or so years ago, I worked on two strokes all the time. I had a setup I built from a radiator pressure testing set that I used to do 'leak down' tests on two-strokes. basically, you make an airtight plug for the intake, and an airtight plug for the exhaust with a hose barb on it. To the hose barb, you connect a line that goes to a hand pump and pressure gauge like a blood pressure dealy. Make sure exhaust port is uncovered, and pump away till you get to X PSI (sorry, I totally don't remember, but probably 10-ish). If all is perfect, it will hold pressure for HOURS.
  6. norton73

    norton73 drinkin' Supporter

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    A leak will make it run lean, if it's in the intake tract or the main seal on the magneto side.
    A leak on the primary side will suck oil out of the transmission, the bike will smoke a bunch.

    Filling the head? :scratch Are you sure you heard that right?
  7. bgoodsoil

    bgoodsoil Dare to be Stupid

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    See? that's the stuff you can't learn from a book. What other secrets are ya'll holding out on us? :D
  8. PFFOG

    PFFOG Richard Alps-aholic Supporter

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    Right seal will not give you an air leak!! It will suck oil from the tranny and make it smoke like a SOB, usually resulted in a toasted tranny, not and engine seizure.

    From the look of the piston, does not look lean, looks like a lubrication failure or a tight piston.
  9. hardwaregrrl

    hardwaregrrl Can't shoot straight Supporter

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    Yeah, Rod was saying that it looked a bit lean, but that it didn't look lean enough for a seizure. When I told him about the carb screw he basically screamed "bingo". I had no idea what an air leak could do so quickly to a 2 smoker. He was surprised I got as far as I did. "What, did you make it to your 3rd heat cycle?" Heat cycle, what the hell is that, I made it far enough to eat pizza and drink beer, then I had a bunch of hot flashes pushing it uphill! Does that count?

    As far as checking for leaks, he began to tell me the process for blocking the top end and filling it with air, and I freaked out trying to figure out how the hell I was gonna do that. So, he wants to see the carb and we'll go from there. I really think that's it, he described a bit about the "cooling" process and how the air leak caused it to heat up.
  10. hardwaregrrl

    hardwaregrrl Can't shoot straight Supporter

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    Yeah, he mentioned something about a rubber boat plug...and I used something very similar in dwv plumbing except it had a wing nut and a large fender washer to compress the rubber. I'll have to figure something out for the hose barb situation. After replacing all the other seals besides the r crank, they all looked VERY good for their age and none were leaking. I will not be splitting cases unless my leak test fails. The bike did not smoke much at all. So, it isn't pointing to the crank seal.
  11. norton73

    norton73 drinkin' Supporter

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    :rofl
  12. PeterW

    PeterW Long timer

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    If the tacho isn't working, Murphy says it's because the plastic gear that drives the tacho AND the oil pump is broken.

    (And you'll seize the engine soon).

    BTDT.

    Pete
  13. hardwaregrrl

    hardwaregrrl Can't shoot straight Supporter

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    Good to know, I'm lucky, my oil pump IS working!!!! I checked it with a drill. But even better news to report, Rod at MSP let me know that the cylinder wasn't totally damaged and only needs a hone and clean. Same size piston and rings. Pretty happy about that seeing as I seized it, oh, about 4 times.:D Got the carb straightened out and just waiting for the piston and a new pilot jet.
  14. bgoodsoil

    bgoodsoil Dare to be Stupid

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    That's great news. I was worried that since you'd already bored it over once that there might not be an over-sized piston large enough to handle it.

    Look on the bright side, at least your head doesn't look like this

    [​IMG]
  15. Beater

    Beater The Bavarian Butcher

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    Ouch. Just a complete noob here, but those valves are supposed to seat flush-like ... right? :huh
  16. bgoodsoil

    bgoodsoil Dare to be Stupid

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    Just for the fun of it I'd like to bang those things back straight and see if it runs. It is a KLR after all.
  17. One Less Harley

    One Less Harley OH.THAT'S GONNA HURT

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    If the head is still on it, I haven't read the entire thread. you can make a plate out of steel to seal off the exhaust, make a gasket from gasket paper and just bolt it in place. If it's sucking air from the ignition side then the bike won't idle very low, going lean will make it idle fast. If the cylinder is off bolt a plate in place of the cylinder, either gasket paper or silicone for a seal. Most likely is it's sucking air it will be on the stator side as the tranny stays lubed and supple.

    Not a $200 bike anymore.........it's hard to buy a non running bike and get it running for very little cash. I've got a MT250, which needed a piston....part of the stator (one coil bad).........and so on and on, can't sell it for what I have in it. Good bike, and lots of lookers, but dang I'm not going to sell it for $500 which is what people want. Hopping to sell it and blow the money on the TAT this summer, how ever far $800 gets me. Work sucks right now, and no classes I need are offered in the summer. SO, might as well hit the road. If I was Brad I could travel for a year on $800, gas will be the worst part.

    Good thing not being married or having kids, you can leave an no one bitches at you. I just can't think of why anyone would get married, obviously not for the sex as that's the 1st thing that goes.
  18. C-Stain

    C-Stain Long timer

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    Miss Jenna...

    Status Please? Inquiring minds want to know...

    :ddog

    I wanna see it run... :evil
  19. hardwaregrrl

    hardwaregrrl Can't shoot straight Supporter

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    Sorry, sorry, sorry. Just got the head and new piston back the other day. And now, by some miracle, I'm working!!! Got a very nice "art project" wood floor repair on a 1912 bungalow. 5/16" top nailed strip, quarter sawn white oak and walnut with buchanan borders!!! It's very fancy.!

    So the bike waits patiently for me to attack it. Hopefully next week I'll be doing 10s of 20s of heat cycles!
  20. robertjludwigsr

    robertjludwigsr Adventurer

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    the MC gods smiled on you too