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  1. #1
    RC Competitor
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    Exclamation Overheating Issues

    my brother has the 2.5 not the newer 2.5R in his TMAXX. he has run 1 gallon of 20% since break in he is having a problem with overheating truck is running great before it gets too hot it only takes about 3 mins before the temps climb over 300 even running with the body off outdoor temps here are in mid 50s the engine is producing a good smoke trail it is actually a little rich because it is dumping fuel from exhaust and the glow plug is slightly damp when removed. after the engine gets too hot it wont start either until it cools completely down is this a sign of premature piston/ sleeve failure ? or is he overlookin something ?
    run it like ya stole it !!
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  2. #2
    RC Racer
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    air leaks anywhere?

  3. #3
    RC Turnbuckle Jr. Snook Man's Avatar
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    All the signs of a worn piston and sleeve if it will not re start until it cools down.
    No slipper/tall gearing/power = broken parts.

  4. #4
    RC Champion
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    I would say check for air leaks and also check the Piston and sleeve pinch.
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  5. #5
    RC Racer
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    my brothers did that and the head was loos and it was sucking in air
    GOT PEDE AND MAXX 2.5R

  6. #6
    RC Racer
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    does it have good compression sometimes when the piston and sleeve wear out the sleeve expands when hott and causes bad tunning and overheating
    big boyz = big toyz

  7. #7
    RC Qualifier
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    Quote Originally Posted by traxxas lover
    my brothers did that and the head was loos and it was sucking in air
    so its fixed?
    A lot is two words. Alot is not a real word.

  8. #8
    RC Competitor
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    gonna tear into it on sat. thanks everyone for your input
    run it like ya stole it !!
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  9. #9
    RC Competitor
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    what does it mean when there is a oily trail on the chassis under the flywheel
    run it like ya stole it !!
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  10. #10
    RC Turnbuckle Jr. Snook Man's Avatar
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    It means the front bearing is leaking.
    A lot of oil slung in a line on the chassis and around the inside of the body is a concern.
    A little oil on the chassis is normal.
    No slipper/tall gearing/power = broken parts.

  11. #11
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    could that have been contributing to the overheat issue? also is it the bearing in the clutch bell or the main crankshaft bearing ?
    run it like ya stole it !!
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  12. #12
    RC Champion
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    Quote Originally Posted by ACE3
    it only takes about 3 mins before the temps climb over 300 even running with the body off outdoor temps here are in mid 50s the engine is producing a good smoke trail it is actually a little rich because it is dumping fuel from exhaust and the glow plug is slightly damp when removed.
    The glow plug will be damp even lean because it won't burn the last bit of fuel before it stalls out. That's not a good indicator of a rich mixture. Has he tried richening the HSN to get the temps to stay down? If it had an air leak, it could be partially compensated for by a richer mixture. I think he needs to step back and try going much richer to the point of poor performance. Then start working it leaner 'til he has good temps and acceptable performance.

    The engine is most likely going but if he can run it more I would try retuning and correcting the temp issue. If he needs another engine, he'll need practice on tuning so he doesn't fry the next one.
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  13. #13
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    Its the crank bearing. There is no oil anywhere near the clutch.
    Phs 2 S-Maxx build- 24/54 gears. Can U say faster?

  14. #14
    RC Competitor
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    yeah were gonna try resetting to factory spec right now he tells me he is about 6.5 turns out on the HSN and its just dumping raw fuel out the exhaust LSN is a turn out past flush i was concerned about the oil under flywheel its not really a lot but just a thin line.
    run it like ya stole it !!
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  15. #15
    RC Champion
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    Factory settings will put you way too lean. Stay where you are and go richer. But my guess is at those settings your engine is toast. That sounds rich even for the winter. Start looking for a good set of bearings, piston and sleeve.
    Phs 2 S-Maxx build- 24/54 gears. Can U say faster?

  16. #16
    RC Competitor
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    Had nothing but problems when i had my 2.5, ditch it for a picco .21 that was good motor, ran like crazy till front bearing went bad.Now i run trx 3.3 seams like a good little motor no problems let.

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