Raptor Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
612 Posts
Discussion Starter #1
I'm getting ready to do a top end rebuild on my 04 Grizzly 660. I'm looking for a little more power out of it. Right now it has HMF full system, K&N, jetted, Dynatek CDI. I'm looking for a bit more all around power. I'm going to run a 102mm 12:1 piston, probably CP, (unless you guys would recommend something else), and I'm not sure which cam yet. I mainly trail ride so most of my time is probably spent in the mid range so I want something that's gonna perform well there. I was thinking a Raptor stage 1 hotcam. What do you guys think??
 

·
Registered
Joined
·
4,836 Posts
Stroker crank? Pump that baby up to 720cc's. The extra stroke will give you more torque too.

389 bucks from hot rods and you wont have to worry about the stock rod letting loose. You could probably find it for cheaper some where else too.
http://www.wrenchrabbit.com.asp1-8.dfw1-2.websitetestlink.com/ProductInfo.aspx?item_id=691

I dont know if I would run a 12:1 in a utility quad unless you plan on running race fuel.

How much of an over haul are you wanting to do? New Ferrea stainless valves? You might consider a set of raptor valve springs to go with the stage 1 hot cam. I don't know if the grizzly springs are stiff engough to run a stage 1 cam. If the oem yamaha springs are to expensive you could always get the Kibble White Springs and drop in a stage 2 cam.
 

·
I am unique
Joined
·
22,621 Posts
Since you have the dyna fs, my recomendations are.............
3 plughead, porting, stage3 cam, upgrade the valves and springs, wiseco 11-1 piston and change the rod...............
 

·
Registered
Joined
·
612 Posts
Discussion Starter #4
I think I'm set on the 720 kit. I found one on eBay for $499. It has the HR +4 crank, JE 11:1, and Cometic gasket set. I know if I don't do it I'll be kicking myself in the ass later.

Right now I don't have the money for porting and valves. So I was just gonna go with a stage 1 cam for the time being. I know I'm not gonna get the full benifit of the 720 with that setup but it should get me through for a while.

Do you guys see any problems with that setup??


Oh yeah, what's a 3 plughead?? Not too familiar with the 660's yet..lol

Thanks
 

·
Registered
Joined
·
4,836 Posts
People moddify the stock head to have a spark plug on each side. You run 3 spark plugs.


I have ran my raptor with all 3 hot cams with no probem. I really dont see a stage 1 limiting any thing. It is all about WHERE you want the power. Running a larger cam will take power away from the bottom end.

I would at least lap the stock valves while you had the head off.
 

·
Registered
Joined
·
612 Posts
Discussion Starter #6
That's the hard part about cam decision for this thing. It's automatic so it's a little harder to judge where I need the powerband at. Which cam seemed to give you the most mid range pull?? That's where it seems mine is lacking the most.
 

·
Registered
Joined
·
4,836 Posts
I would probably go with a stage 2 cam if it was mine. Are you running larger tires? Any clutch springs / slider mods? Those will have an on the over all feeling of riding as well. If you dont want to push you luck then it will run fine with the stage 1 cam.

The 4mill crank will give you more low end pull. The stage 2 cam will give you more mid to top end.
 

·
I am unique
Joined
·
22,621 Posts
I think I'm set on the 720 kit. I found one on eBay for $499. It has the HR +4 crank, JE 11:1, and Cometic gasket set. I know if I don't do it I'll be kicking myself in the ass later.

Right now I don't have the money for porting and valves. So I was just gonna go with a stage 1 cam for the time being. I know I'm not gonna get the full benefit of the 720 with that setup but it should get me through for a while.

Do you guys see any problems with that setup??


Oh yeah, what's a 3 plughead?? Not too familiar with the 660's yet..lol

Thanks
A 3 plughead is a mod that converts your cylinder to accept three spark plugs all firing at once, this promotes better fuel burn, better fuel efficiency, better low end power and response, and a longer high rpm power band, in all one hell of an engine.............
 

·
Registered
Joined
·
612 Posts
Discussion Starter #9
I'm running 26" Bighorn 2.0's. No clutch mods that I know of. Im still new at this automatic stuff and theres ALOT to take in. I decided against the stroker crank because I saw alot of people were burning up their wet clutches with the power that they put out, so I'm gonna be going with stock stroke. Still gonna go 102mm with the piston though. TQS has a CP 11:1/12:1 with HC1 and gaskets for a pretty good price so I'm gonna order that up. For the crank should I go with a OEM or go with the Hotrods??

Also, do the CP pistons run true to their compression ratios or are they actually lower then stated?? I know the TECH pistons have a corrected deck height but not sure on the shelf pistons. I ran a 12.5:1 440 kit in my 400EX with no detonation on 93 and I would like to go with as much compression as I can get away with on pump gas. I know the 440 kit wasn't a true 12.5:1 though. I think it was actually about 11.7:1. I ride at about 700-1300 ft.

Thanks for the help guys. It's much appreciated. :cool:
 

·
Registered
Joined
·
612 Posts
Discussion Starter #10
A 3 plughead is a mod that converts your cylinder to accept three spark plugs all firing at once, this promotes better fuel burn, better fuel efficiency, better low end power and response, and a longer high rpm power band, in all one hell of an engine.............

That sounds badass but also expensive!! Who does those?? Sounds like a good future mod to keep in mind.
 

·
I am unique
Joined
·
22,621 Posts
I just bought a 660 Rhino a couple weeks ago, and this engine will have a 3 plug raptor head which I will build, stage 3 cam, hot rod connecting rod with a stage 3 cam, I will also use dual FCR 39mm carbs........................
 

·
Premium Member
Joined
·
956 Posts
I just bought a 660 Rhino a couple weeks ago, and this engine will have a 3 plug raptor head which I will build, stage 3 cam, hot rod connecting rod with a stage 3 cam, I will also use dual FCR 39mm carbs........................
Willykiller you a sick puppy but in a GOOD way, LOL
 
1 - 12 of 12 Posts
Top