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Discussion Starter · #1 ·
i picked up a 2009 brute force 750 4x4i the other day...they guy said he dosent know what wrong with it and its something to do with the fuel...i fixed the fuel problem but it has 0 compression in the front and 30 in the back..i used a micro cam and the piston looks good...i can still see the cross hatching on the jug walls so that looks good...the guy said a shot just did the valves ( i checked them anyways and they was good) he said the motor was not that old so there is no way it could be blown...it has been sitting..any ideas what it could be? could it be the cam chain not set right? or any way to know for sure if its blown or not?..its how trying to start at all..not even signs of starting..but turns over easy..good spark..
 

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Does it have the stock ecu? Was it torn down once before, if so did he know if the piston abd/or rings were done?

Could possibly be a gasket leak.

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Discussion Starter · #4 ·
Does it have the stock ecu? Was it torn down once before, if so did he know if the piston abd/or rings were done?

Could possibly be a gasket leak.

Sent from my SM-N950W using Tapatalk
im not sure..the guy just said the motor isnt that old and there is no way its blown..a shop just did the valves on it (the tag was still on the key ring so i know it was in a shop at some point) there was a dyno jet power commander on it i took off for now just to make things easy..
 

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Discussion Starter · #5 ·
Check the valve timing and operation, then to a leak-down test. It's never going to even hint at starting with those numbers.
i never did timing like this..i have only worked on push rod motors..i was watching videos how..could i just set it to TDS and see if the cam lines up at the top...or would i have to check all of it at the bottom and take all that apart to? would be so much easer if i only have to check the top..im thinking if the top is good then the bottom should be good right? because if the bottom is off then the top would be off also?
 

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Yeah then the leak down would show a blown or leaking gasket. Would not be unexpected that the timing might be off as well.

Trying to recall which parts of the heads came off in which sequence to pull only the valves.

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i never did timing like this..i have only worked on push rod motors..i was watching videos how..could i just set it to TDS and see if the cam lines up at the top...or would i have to check all of it at the bottom and take all that apart to? would be so much easer if i only have to check the top..im thinking if the top is good then the bottom should be good right? because if the bottom is off then the top would be off also?
Bottom marks are on the stator/flywheel, you have the service manual?

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Discussion Starter · #9 ·
Yeah then the leak down would show a blown or leaking gasket. Would not be unexpected that the timing might be off as well.

Trying to recall which parts of the heads came off in which sequence to pull only the valves.

Sent from my SM-N950W using Tapatalk
just googled what a leak down test is..so from my understanding is, you put a ounce of oil in the cylinder and compression test it..then test it again after a minute and if it changes, the rings are bad? idk if that will work on the front one at 0..but should be able to test it on the back thats at 30
 

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Discussion Starter · #10 ·
just googled what a leak down test is..so from my understanding is, you put a ounce of oil in the cylinder and compression test it..then test it again after a minute and if it changes, the rings are bad? idk if that will work on the front one at 0..but should be able to test it on the back thats at 30
oh i see...you use a air compressor and you listen for the leaks..i dont have the right tool to know the amount of pressure in putting in but it says 100psi so as long as i dont go over that i should be good..
 
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