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Detonation?


Sands

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I think I will take the risk. I will not split the cases. I will put new pistons and domes and verify some leak on boots and check the gas cap. About timing? +4 degrees?

+4 should be fine dont bump the comp any more that what you have pump gas is really only safe up to about 150psi

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Make sure you do a leakdown & compression test before starting the engine after new pistons & domes are installed. After you do a couple of heat cycles check compression again. You can never check your compression enough.

i check my comp after every 4 tanks of gas and now that i have a 3k motor i am really anal about maintenance

Edited by coryv4
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Just drop me a pm and ill respond i get so many emails and pms everyday im sure some slip threw the cracks.

 

If you didnt leak down test the motor then you are just spinning your wheels guessing what happened. You have to leak down the motor to be sure its sealed up. If its not sealed up then your getting extra air hence "lean" which = detonation.

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Just drop me a pm and ill respond i get so many emails and pms everyday im sure some slip threw the cracks.

 

If you didnt leak down test the motor then you are just spinning your wheels guessing what happened. You have to leak down the motor to be sure its sealed up. If its not sealed up then your getting extra air hence "lean" which = detonation.

 

Did you get any PM from me? Sent me a PM with your email.

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Take off tha gas cap and try to blow on the vent tube, if you cant blow air into it that could be a big problem, take out all the metlal and drill out the plastic part bigger. Then you wont have any problems flowing fuel or having a vacuum.

 

word to the wise.....if your plugs start backing themselves out.....you better start looking around for a way to fix it....

 

 

 

 

 

Those last 2 posts hit it perfectly. Lets ask if your plugs backed out while you were cruising slowly . That tells us it was lean on the needle for some reason but could be from air leaking into the motor. Intake boots can definately cause an air leak, if you ground the inside of the boots to fit larger carbs than more than likely they are not sealing.

 

Cam I can show you a few domes from buds builds that are hammered from detonation. Heres a good example. All from detonation. http://forums.atvdragracers.com/topic/11407-trx-370-cylinder/

 

 

i read that post and it says the crank let go the heavy damage is from the debris hitting the dome/ piston.. i have never seen heavy pits and impressions from deto alone. its ALWAYS been something in the motor failing from the deto and smashing in between the piston and the dome. talk about stress on a crank after that.. i've seen a bunch of toasted car pistons from massive deto and they are burnt up not damaged.. maybe i am wrong just what i have seen when there is damage like that its time for a teardown.

 

if you put that thing backtogether whatever is weak int he bottom end is going to take the cyl with it..

 

i'd love to see a detonation only post made up?? maybe HQ needs a engine technical area? i think i have some various domes with deto only and some heads with debris damage as well as deto. i could post them up..

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