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Rebuilding motor ?'s

2529 Views 9 Replies 6 Participants Last post by  450mud
Im going to rebuild the motor because its smoking pretty bad! What should I go with instead of stock? I do alot of mudding and need HP for 27" mud bugs that I will be getting as soon as I finish with the motor. Any suggestions would be appreciated.
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Wow you have a lot of oprions. You can bore it stroke it higher compression piston and cam. Your bike has all of those available for it. It is a 450 right? I forgot to look closely at your sig. Try checking out 4stroketeck and thrumper racing and highlifter webcams they all have products for you. GL and have fun.
big bore

I was kind of just wanting to go with a piston kit. Now i just read on another site that I cant bore the jug because it stripps some coating on it and then all you have is aluminum wich is not good for the rings and piston. Is this true?
First off why are you rebuilting it, was it run hot, swamped or just time for it?

the foreman 450 sleeve is not coated with anything and can be bored. I would go with just an overbore and maybe a HP kit(exhaust,jetted,filter) The foreman will have no problems turning the 27" bugs.

Well it started smoking after about 80 hours on the motor after beeing swamped a bunch of times. So i took it to a Honda dealer and they overlooked the water in the diffs and crank case and went ahead and rebuilt it. It went about 20 hours and it started smoking again, this time the water only came up to the top of the tire at the deepest. So I took it apart because it did not have waranty anymore, all the rings and bearings were good nothing that would make it smoke in my opinion, so figured it was the valve seals and replaced them. put it back together and it still smokes. thats why im just going with all new parts. I will take the case apart and clean off everything (wich I should have done the first time). I read somewhere that sand and other crap can get into the case and get pumped with the oil and scratch the cyl wall!
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yup , same thing happened to me . very important, buy a new oil cooler !!! the grit never comes out . i used mineral spirts with a air powered solvent blower to clean mine, its was from a cheap tool store worked good . i also change my oil every 100 miles x 3.
wait you change your oil 3 times every 100 miles ! god, id take to oil outa ur bike and put it in mine haha, dang thats crazy if thats what you mean, is there a purpose to that, i check my 3 times every 100 miles haha
well if you look his engine is fairly worked over so if it was me i would take good care of it too
well that way i can check for metal and more grit that might be in there still . its just a few dollars to spend ,beats a top end again.

Hey fellas, just an update!
I rebuilt the top end and the smoking stopped!
I whent ahead and bought a WISECO piston, I dont know exactly what I brought the displacement up to but the box says (Clear:0.0030(.076mm))
I also bought a Quad works performance kit and snorkel. I can really feel the difference in performance. I am very happy and only spen about $320. I took it to a shop and they wanted $1300 to rebuild my top end.
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