I have a chance to get 2007 650 Brute Force at a good price but it has been abused. The is some engine noise. Sounds like a rattle, but it runs ok. Tires and wheels are shot, other small problems. Had a snorkel kit so I think it has been under water a time or two. The local dealer thinks it is juck. The big problem is the engine noise. It sound like a chain rattle. How hard is it to replace the chain.

 

Well this would have to be a really GOOD DEAL to buy. The cam chains on these motors take along time to change. I think that flat rate is like 8 hours lol. The other thing is the noise that you head can be piled up rod bearings. I have rebuilt 3 750 brute force motors which is all same pile. I myself would buy a 660 grizzly you can pick one of those up for starting at 3000.00

 

what do you think this brute force is worth

 

Well if the motor is really bad 2000.00 less than low book. Sounds like it's pretty ruff so I would give about 1500 to 1800.00 for it.

 

<div class="FTQUOTE"><begin quote>Originally posted by: cluby

The other thing is the noise that you head can be piled up rod bearings. I have rebuilt 3 750 brute force motors which is all same pile. </end quote></div>

Not so. When rod bearings begin to go bad, they do not make rattling noise. It's more like deep/heavy KNOCKING noise which is most noticeable at low rpm like when idling. Rattling noise is more likely due to the worn out cam chains. Best way to find out is to use the mechanic's stethscope to pin-point the source of the noise.

 

True, and a worn drive clutch also makes a rattling noise as well. Until we can get a updrage and be able to touch and hear things we are just guessing

 

<div class="FTQUOTE"><begin quote>Originally posted by: cluby

a worn drive clutch also makes a rattling noise
</end quote></div>

If you are talking about the worn out shims (aka buttons or shoes) on the Spider arms, it sounds more like knocking (but little lighter knocking than bad rod bearing) or more like clunking sound, rather than rattling. But the original poster said the noise came from the engine, not the converter. That's why cam chain would be the primary suspect.

Here is the diagram of drive converter with the red arrow pointing at the shims I am referring to, in case that is the source of the noise.


There are 8 buttons on the Spider (cross-webbed part), 2 on each arm. As the they wear out (becuase they keep banging against the fingers of the movable sheave whenever the rpm changes), the clearnace gets larger between the button and the finger of the sheave. The clearnce is needed because the Spider part has to move in and out from the movable sheave and the maximum factory clearance is something like 8 thousandths, fairly tight. The knocking or clunking noise is most noticeable when idling. So, what happens if you don't adjust the clearance? Nothing really dramatic but the noise would get worse. And to adjust the clearance, you have to replace the buttons with different thickness. Buttons come in thickness of 7.2 to 8.0 mm.