RE ; Mudbuster cam and boring out to a 686

[silverstar32]

hi am am wanting to bore my 2005 grizz to a 686cc
was wondering if i should use a wiseco piston
i ride around rocky
what compression should i get so i can safely use premium pump gas?
which cam should i get?

any input would be greatly appreciated

 

[AreWeThereYet]

Call this guy, he is a yamaha motor guru.

Chris
Benchmark performance
760-484-0986

 

[Mikehunt]

Wiesco is a good brand of piston to use, stay under 11to1 if you want to use pump gas

 

[Gunny]

Silverstar, have you done this yet or called the guy "AreWeThereYet" suggested ?

I did this mod to my 03 Grizz, I used a JE piston 10:75.1, Raptor Cam & raptor valve springs. Did it back in Aug of 09. Runs great & lots of torque.

I also did some mild porting & polishing. Did it help ?? I don't really know. But it sure didn't hurt !!

 

[grizzlydave]

I did the 686 in my 06 660, with the wisco high compression 11.5/1 piston last year, I also put in the mud buster cam at the same time, there was a difference in torque, and i still run pump gas (91) octane it runs fine. I ride mostly the Nordegg are and occasionally around Boyle and have had absolutely no issues. When I had questions about doing the work I talked to Kevin over at Rapid and he gave me all the info I needed.

 

[sumx54]

I did the 686 in my 06 660, with the wisco high compression 11.5/1 piston last year, I also put in the mud buster cam at the same time, there was a difference in torque, and i still run pump gas (91) octane it runs fine. I ride mostly the Nordegg are and occasionally around Boyle and have had absolutely no issues. When I had questions about doing the work I talked to Kevin over at Rapid and he gave me all the info I needed.

X2....... I put over 4500kms on this kit and sold it 3 years ago and it's still pulling good to this day for a buddy. Must be over 6k on it now. I also did a polish.

 

[the_real_wild1]

What are the kits worth? May have to look into it again.

 

[Gunny]

What are the kits worth? May have to look into it again.

This is the kit I used. It had everything in it. All new O-rings, gaskets, even valve stem seals & new seals for the exhaust headers.

686 102mm Big Bore Kit Yamaha Raptor Rhino Grizzly 660 - Automotive ATV Parts & Accessories

 

[the_real_wild1]

Not too bad for price.

 

[Gunny]

Not too bad for price.

Only other costs I had were for the bore job, oil, antifreeze, etc. And if ya don't have a pipe & air filter upgrade, this would be a good time to do those.

And as far as jetting, I'm running one jet richer than stock for my altitude.