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  1. #1
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    Trx 3.3 Need help... New piston, sleeve and connecting rod

    OK heres problem. Well i started by breaking the connecting rod, which had put a little dent in the side of the piston ...So i decided to get new connecting rod with new piston & sleeve. Well after following all the engine rebuild intructions with intense care... I have discovered that the new piston and sleeve are not fitting each other properly (too tight). So when everything is back together, leaving the head off I can't turn the crankshaft a full revolution. The piston falls short of TDC by about 1mm. Not sure if it is a defect of the product or it is correct and I should just finish putting it back together try and start it, which i am very doubtful of doing. I thought maybe i could use the old sleeve which wasn't damaged when the connecting rod broke. I have tried new piston in the old sleeve and it seems fine, it is tight aswell but it does make it to TDC.

    Any comment would be greatly appreciated

  2. #2
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    I would make sure that one you do not have you piston and connecting rod in backwards, seems like you took care when rebuilding. But it can happen to the best of us on a new rebuild if not paying close attention. If that looks all good just sounds like you have a tight pinch and sometimes with a new motor you can place some after run oil on the top of the piston to help lubricate, and before starting heat up the head of your engine with a hair dryer if all else looks properly assembled from the rebuild.
    rusler vxl, rusler xl-5, jato 3.3, losi 5ive T

  3. #3
    RC Champion
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    It should be tight. Like Chad stated. Lube it up, warm it up, and spin it with starter with out plug for a few seconds. It will loosen up for you. With a new piston /sleeve it gonna be real tight. Without prelubing and warmng up. Damage can be done to connecting rod before you get it broke in. I prefeer to use wd40 or Marvel mystery oil for spinning the engine.

  4. #4
    RC Champion
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    That's it^, a couple drops of oil on the conrod and piston with some heat from a hair dryer.
    erbe emaxx 26maxx s27revo 18tmrevo XXL platinum

  5. #5
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    Alright, thanks for the advice. I will give it a go and try and heat the head with the hair dryer. The piston is in correctly i have checked it that many times it is not funny. Also tried the with the WD40.... I will let you know how i go. If it doesnt work could i use the old sleeve or just get a refund for the new one ....Maybe i should have just used engine replacement programme.

  6. #6
    Marshal Double G's Avatar
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    Don't use a new piston with an old sleeve. Otherwise you'll be buying new parts again.
    The sleeve is tapered at the top so the piston does not need rings. It's the way the sleeve was designed so turning it over with some lube before starting and heating it up will give you better results.
    The Super Derecho

  7. #7
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    Thumbs up

    Well thankyou all for the help... You were all right. Silly me was trying to turn the crankshaft with no flywheel on. So all totally put back together on the car. Didn't want to start it today as its 40 degrees outside (stinking HOT). I did an after run maintenace and the starter box has no problems turning it over. No need for the hair dryer.

  8. #8
    RC Turnbuckle Jr. Nitronaught's Avatar
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    Quote Originally Posted by ChaosRulz0 View Post
    Well thankyou all for the help... You were all right. Silly me was trying to turn the crankshaft with no flywheel on. So all totally put back together on the car. Didn't want to start it today as its 40 degrees outside (stinking HOT). I did an after run maintenace and the starter box has no problems turning it over. No need for the hair dryer.
    The hair dryer is to pre-heat the engine creating expansion, this way when you turn over the engine there's a lot less stress on the internals....

    I highly recommend preheating the block of any new nitro engine.... Not for the startes sake, but to help with less strss on the internals...

    I'm sure we ALL could do with less tress...
    Founder of H.U.A.
    Hop Ups Anonymous

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