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Discussion Starter #1
I picked up a Brute Force 750 today that was run out of oil and has a engine knock. I'm prepared to do a full rebuild but I thought I might as well try to put some oil and a additive in it first in case it goes away. So I'm looking for y'all suggestions for a good additive. Also how would you guys recommend running it once I add the new oil as to increase the chance of it fixing itself. Idle or fast? Or in between?

Thanks in advance!
 

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If it is knocking due to running dry, there's nothing in a bottle that will fix it. Spend your money on parts.
 

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Discussion Starter #4
Thanks @NMKAWIERIDER and @kickstart for you advice. I'm just now getting started on it cause of the holidays but better late than never! Does anyone know of a good place to get the crankshaft rebuilt? I've called around and knowbody is willing to do it so far. Also what's your guys opinions on Wiseco Pistons? I've heard bad things about HotRod cranks but what about there connecting rods? I'm thinking OEM but they're about 100 bucks more than the Hotrod.
 

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Thanks @NMKAWIERIDER and @kickstart for you advice. I'm just now getting started on it cause of the holidays but better late than never! Does anyone know of a good place to get the crankshaft rebuilt? I've called around and knowbody is willing to do it so far. Also what's your guys opinions on Wiseco Pistons? I've heard bad things about HotRod cranks but what about there connecting rods? I'm thinking OEM but they're about 100 bucks more than the Hotrod.
Well, personally, because Kawasaki only has I think 3 different rod bearings there is nothing from Kawasaki that will be able to handle a ground crank. And people that found others makes are having different and not always desirable results so my advice is bite the bullet and go with a new Kawasaki crank and bearings or get someone's complete crank kit..not piece-meal it together. And Wiseco makes a good piston. See if Big Kev is still in business.
 

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Well, personally, because Kawasaki only has I think 3 different rod bearings there is nothing from Kawasaki that will be able to handle a ground crank. And people that found others makes are having different and not always desirable results so my advice is bite the bullet and go with a new Kawasaki crank and bearings or get someone's complete crank kit..not piece-meal it together. And Wiseco makes a good piston. See if Big Kev is still in business.
 

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I have wiseco pistons in my ride. Been really pleased with them. They are little works of art. Customer service is also very good.
Just make sure the rings are gapped within spec before you assemble.

I think Dman knows somebody who does good crank work. Maybe he will chime in.
 

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Yep, Bobby Beam at revzcycles.com
He has all kinds of goodies for brutes.
 

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Discussion Starter #10
Thanks for all the info guys! I'm going to tear into it before I buy anything but you definently have pointed me in the right direction. Is there a free repair manual anywhere I can download or do I need to buy one?
 

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Discussion Starter #11
Here is the damage. I'm also going to need to bore the cylinders and Wiseco only makes a Std bore and a +2mm overbore. Do you think I'll have any problems with that big of a overbore. I tried searching around but couldn't find any good answers. Also has anyone used the REVZcycles crankshaft service and if so do you think they can do anything for me or are these toast?

Thanks!
 

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You'll like the +2 pistons. That's what I have. Pretty significant increase in power.
 

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The 750 has a Nikasil coating in the cylinders. You will need to have the coating re-applied, or the cylinders sleeved.
 

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Where did you guys get the work done? @kickstart did you have to make any other modifications to handle the bore?
Thanks for the replys.
I didn't have to do anything but bore and hone, but my engine already came with steel sleeves. Your's is coated, so it will require a bit more work.
Any machine shop can bore cylinders. But you should probably contact an engine builder (like VFJ or Big Kev) who sells Kawasaki kits and see if they recommend or are setup for sleeving or replating.
 

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By the time you have them bored and re-plated its probably more cost effective to get good used cylinders. If it was me I would price out a set of used cylinders and a standard bore kit with cams from fst or vforce john. +2 pistons will give a small boost in power, you might feel it but cams are where its at with these motors if you want to make power. Ask yourself what you want out of this machine then get a game plan. Remember Wiseco's are high compression so you'll want to run premium.
 

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Bobby Beam at revzcycles sells all the parts needed.
His business is very reliable.
 

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My builder would not put used cylinders in a freshly rebuilt engine without boring and/or honing the cylinders to fit the new individual pistons. Unfortunately, with nikasil plated bores, that means either sleeving or replating.
Even on my sleeved cylinders, he wouldn't touch my job unless I supplied them with the pistons first so they could bore and mate the parts.
Also, every aftermarket piston you buy will probably be higher comp than stock whether you go standard or oversize. Wiseco are in the 11's, Big Kev's are in the 12's no matter what size.
I looked all over for pistons with the stock comp in the 9's, but couldn't find any except oem. I didn't want to be limited to running 91+, eth-free octane. The best gas I can readily get anywhere in Utah is 88 eth-free. I ended up getting Wiseco's with 11.5:1 comp, and I ran 88 with octane booster for awhile. But I eventually found that too big of a pita for how much gas i buy, so I stopped adding booster. I have not seen or felt any difference with straight 88 eth-free. I've looked at the piston domes after thousands of miles of running nothing but 88 clear, and there has not been any damage done. That being said, my 88 is formulated at ~ 5000' elevation. Ymmv at sea level.
 

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Nothing wrong with used cylinders as long as they are not scratched. Nikasil is pretty strong and if its not scratched then a simple deglaze is all it will need. I've melted pistons in snowmobiles with plated cylinders and I just cleaned up and threw in a new piston and back on the trail in a couple hours. If a 150+ hp sled screaming at 8k can melt a piston and still be able to reuse the cylinder then im sure a clean used 750 cylinder on ebay will be just fine.
 

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Nothing wrong with used cylinders as long as they are not scratched. Nikasil is pretty strong and if its not scratched then a simple deglaze is all it will need. I've melted pistons in snowmobiles with plated cylinders and I just cleaned up and threw in a new piston and back on the trail in a couple hours. If a 150+ hp sled screaming at 8k can melt a piston and still be able to reuse the cylinder then im sure a clean used 750 cylinder on ebay will be just fine.
Wow, that's a pretty good testimonial for Nikasil! But my builder wouldn't let me put new pistons in cylinders unless he can bore to fit. He never just throws new pistons in cylinders, new or used, plated or unplated. He said he's just seen too many issues with low comp, oil burning, skirt wear, stuck rings, etc., and he loses money on doing jobs twice.
 
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