# Brute knocking when accelerating!!



## Mikescar1 (Feb 20, 2016)

Hey guys I'm new here and to riding. I bought a 06' BF750 and it ran great. We made a couple of rides and had no problems. Unloaded it the other day and when to start riding and it is making a knocking noise when accelerating not when idling in neutral or being revd in neutral either. I changed the oil, took the carbs off and cleaned them thoroughly. The bike starts right up but knocks when driving any help is greatly appreciated! I found a YouTube video that shows it perfectly. This video is not my bike just the same situation. I couldn't figure out how to put it in here so here is the link. Thanks guys!


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## 2010Bruterider (Jun 20, 2010)

Take the belt cover off and inspect the belt. It might have a piece hanging off slapping the inside when your moving. 


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## Mikescar1 (Feb 20, 2016)

Thanks, I took the belt cover off just now. It's got a couple wear spots but nothing hanging. It's definitely coming from in there though. I rode it around the yard with it off to listen and it clacks it when I hit the gas and feels like it reduces power a lot.


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## Mikescar1 (Feb 20, 2016)

Now it's doing it in neutral.










Got up to about 10 mph and it died and struggled to start then finally started and drove back to house.


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## NMKawierider (Apr 11, 2009)

She's done. It's either loose rod bearings or completely gone chains and tensioner bars. Talk to N-flow on rebuilding.


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## Mikescar1 (Feb 20, 2016)

That's terrible news... Thanks for the help!


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## NMKawierider (Apr 11, 2009)

Mikescar1 said:


> That's terrible news... Thanks for the help!


Well, just to make sure, take the primary off and start it. If the sound is still there, don't run it anymore. If it throws a rod, then you are looking at a new case.


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## dman66 (Feb 20, 2011)

That sucks.

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dman66 said:


> That sucks.
> 
> Sent from my XT1080 using Tapatalk


The first thought was a rod knock.

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## Mikescar1 (Feb 20, 2016)

Was hoping for a clutch swap or something easier. It started smoking pretty heavy thick white grey smoke too.

---------- Post added at 01:39 PM ---------- Previous post was at 01:14 PM ----------

Anyone have any ideas on how much it costs to fix?


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## dman66 (Feb 20, 2011)

Are u doing the work or is someone else ? How much did u buy her for ?

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## Mikescar1 (Feb 20, 2016)

Probably someone else, that's a little more than I can handle I think. I paid 2500 for her


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## NMKawierider (Apr 11, 2009)

Talk to n-flow. It will be right.


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## dman66 (Feb 20, 2011)

You'll spend at least 2500.00 for a rebuilt engine. It may be time to cut your loss or spend some money on a machine that may not be worth spending on. How many miles u have on her .

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## rmax (Nov 21, 2009)

dman66 said:


> You'll spend at least 2500.00 for a rebuilt engine. It may be time to cut your loss or spend some money on a machine that may not be worth spending on. How many miles u have on her .
> 
> Sent from my XT1080 using Tapatalk


theres a couplle of builders in the south that can beat that price 
dont know where you are shipping might be a problem


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## nFlow (Aug 12, 2010)

NMkawierider, thank you for the recommendation! Mikescar1, we can get your engine to like-new and back out riding in about 14 days from when we receive your engine. We can completely reman the BF 750 engine for $2,795 with Free Shipping both ways in the lower 48 states. Our reman process includes a complete tear down of the engine, washing and media blasting, replacement of worn/damaged components, in house CNC machine work, reassembly by our skilled techs, final inspection/testing, and shipping back to your doorstep. All you have to do is strap the engine to a pallet and we take care of the rest including arranging all shipping logistics. If you give us a call at 812-402-8282, C.W. will be happy to answer any questions about how the process works. We reman about 1,000 powersport engines per year so our techs are well versed in the BF 750. Thanks.


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## Mikescar1 (Feb 20, 2016)

Just an update, I went ahead and tackled it myself. Got down the rods and crank, bearings and rods looked good with no slack or slipping. I did have a broken tensioner guide on the front cylinder timing chain and the timing on the front was off 180 degrees. Went back with all new gaskets, fixed timing and new guide. Had some stretched piston rings and swapped those. Got it back together and adjusted my valves last night. It cranked up, I haven't rode it yet will check tonight and see if everything checks out.


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