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5TH-SCALE-FREAK
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« Reply #1 on: October 30, 2008, 12:55:15 PM » |
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And in the head the rough finish is in the very top of the head right where spark plug sits in.some one please tell me what is this?Remenber now the motor was still running great with lots of power and nasty torque.
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monotheist
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« Reply #2 on: October 30, 2008, 02:22:26 PM » |
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My god, your motors got freckles!
Wonder if that is caused from pre-detonation or pinging from to low octane fuel or could it be some porcelain from the spark plug has broken of and bounced around in there?
Never seen anything quite like it.
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 Melbourne, Australia |
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Nox
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« Reply #3 on: October 30, 2008, 03:28:09 PM » |
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I would say your motor is suffering from detonation and on the verge of being lean or like Mono said poor fuel.
The lack of carbon deposits on the piston or head indicate detonation. The temperature rises dramatically inside the head when this happens and removes the carbon deposit layer which then begins to melt the aluminium, hence the rough speckled look.
This may have not been happening for the life of the motor (it would have exploded by now), it could just be the last 1 or 2 tankfulls.
Maybe check your fuel and change to another source or up the oil ratio a little.
If you suss about your fuel you could always use some octane booster.
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MCD Baja 1000 EVO 2
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5TH-SCALE-FREAK
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« Reply #4 on: October 30, 2008, 04:43:57 PM » |
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Yea but I use the same fuel on every rc that I have and the rest of the other dont have this.I honestly never seen nohing like this.
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Nox
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« Reply #5 on: October 30, 2008, 05:33:41 PM » |
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Try increasing your oil ratio to say 20:1 or even 15:1.
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MCD Baja 1000 EVO 2
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Clubin
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« Reply #6 on: October 30, 2008, 09:57:48 PM » |
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Look at the coil, the ends look a little mashed, could that have caused this?
Good one though.
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Alluminum FG MB
MCD Baja 1000 EVO III
MCD Race Runner EVO III
Redcat Rampage MT
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5TH-SCALE-FREAK
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« Reply #7 on: November 01, 2008, 02:38:31 AM » |
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Look at the coil, the ends look a little mashed, could that have caused this?
Good one though.
the coil looks like its spreaded apart a little. |
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Clubin
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« Reply #8 on: November 01, 2008, 06:31:01 AM » |
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Look at the coil, the ends look a little mashed, could that have caused this?
Good one though.
the coil looks like its spreaded apart a little. A lot? lol |
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Alluminum FG MB
MCD Baja 1000 EVO III
MCD Race Runner EVO III
Redcat Rampage MT
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5TH-SCALE-FREAK
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« Reply #9 on: November 01, 2008, 04:22:51 PM » |
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YES.WHY?
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Clubin
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« Reply #10 on: November 01, 2008, 05:32:35 PM » |
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Just a thought, it might have somthing to do with altering the timing.
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Alluminum FG MB
MCD Baja 1000 EVO III
MCD Race Runner EVO III
Redcat Rampage MT
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RIFF-RAFF
Newbie
 Offline
: Burlington Ontario
Posts: 45
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« Reply #11 on: November 18, 2008, 11:58:54 PM » |
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Yea but I use the same fuel on every rc that I have and the rest of the other dont have this.I honestly never seen nohing like this.
The compression ratios could be different from one motor to the next.If you run too high a compression for the fuel you're using you'll get pre-ignition and the effects you're seeing can be the result.Try a higher octane fuel which slows the burn and prevents pre-ignition. Frank |
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MCD Baja 1000 x2
Traxxas Revo X2
Traxxas Jato 3.3
HPI Savage
HPI MT2
HPI Firestorm
Losi LST2 X2
Losi Muggy X2
Losi Micro Baja X2
Associated RC18T
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Streamlinerc
Newbie
Offline
: Athens Ga
Posts: 2
Cant hang with the BIG DOGS we can call your mama
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« Reply #12 on: December 18, 2009, 04:48:19 PM » |
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Its very likly that the pitting on the piston head is from water in you fuel.
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jolsen
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« Reply #13 on: March 10, 2010, 12:21:36 AM » |
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looks just like my friends lost upper bearing cage did upper rod bearing have cage on it metal got into engine
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baja 1000/3 race runner/3 race runner ultimate / bergosoni factory team car/revo 3.3 /1/8 miss bud gas hydo........
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Filmoor
Newbie
Offline
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Posts: 22
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« Reply #14 on: March 10, 2010, 07:47:45 PM » |
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Looks like you;ve been running it lean fella, The dark patch in the centre of the piston crown is burnt oil cuased by high cylinder tenperature, is there a dark patch on the under side of the piston crown ? As you said it had loads of power but a lean engine will rev higher and create more torque.
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