# bad noise after rebuild 650 brute



## ernieb62 (Aug 12, 2011)

i just rebuilt my first 650 brute. I put new pistons and rings in a 2008 650i that had been under water. cleaned everything real good and flushed engine real good. Motor cranked and ran great in my shop but when i ran it down the road for 5 minutes, I started getting a loud upper engine noise???? Any ideas what to look for tomorrow!!!!!!


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## rmax (Nov 21, 2009)

what does it sound like, tapping ,knocking, grinding


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## Brute650i (Dec 17, 2008)

Same questions as above.


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## ernieb62 (Aug 12, 2011)

More like a slapping noise and gets louder as you throtltle up. Sounds like it is coming from the front cylinder also. I am taking the valve covers off now so i will respond back with anything i see that dos not look ok---Thanks


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## Brute650i (Dec 17, 2008)

I am thinking rod bearings. They can sometimes sound like the top end but will actually be in the bottom end


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## LM83 (Jul 23, 2010)

Brute650i said:


> I am thinking rod bearings. They can sometimes sound like the top end but will actually be in the bottom end


That's what I'm thinking. 


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## ernieb62 (Aug 12, 2011)

Well you are correct as usual!!!! The front rod must have spun a bearing because I now have a ton of up and down slack in the front rod. Ran great for 15 minutes and then the noise started and got worse. is there something I did wrong or is this a result of it being sunk in muddy water 3 weeks ago which is why i was having to rebuild it anyway. Also, how many hours should I expect an average shop to charge to replace the crankshaft and rod assembly---Thanks


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## Brute650i (Dec 17, 2008)

If you did the top end you can do the bottom. The parts are about $700 from me to do bottom end with chains, gaskets, crank, rods, and seals.


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## 05BF750i (Apr 26, 2012)

Brute650i said:


> If you did the top end you can do the bottom. The parts are about $700 from me to do bottom end with chains, gaskets, crank, rods, and seals.


i am rebuilding my 750 now (spun rod bearings), i bought everything i need to redo it but not the chains, im sure its always to go new on a rebuild but am i ok to use the factory chains or you think they are stretched?


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## CaN_Am_RyDeR_1000 (Oct 22, 2013)

It can't hurt to replace the chain. Might as well do it now then have it be stretched and cause you a laundry list of problems later.


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## rmax (Nov 21, 2009)

I always replace the chains in these engines

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