Juiced up 660

4619 Views 14 Replies 5 Participants Last post by GRIZZLYWIZARD, Jul 29, 2009

BATTLEGUN

Discussion Starter · May 28, 2009

I'm starting a new project. I'm going to trick another 660 out. It's a 2004 660 with about 250 hours. We're going to bore it to a 686, put in a crank, add a cluctch kit, airbox lid, and of course jet it out.

The quad already has a hmf utility w/o the qc, 26" Mud Bugs on 12 ITP's. It runs strong now, can't wait to see the difference.

Does anyone here have any experience with boring a quad? If so, what where your take aways? (What would you do different, or what wouldn't you do at all?)

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GRIZZLYWIZARD

· #2 · May 29, 2009

Boring a cylinder is pretty straight forward. Since you a boring larger, you will want to send the cylinder off and have the cylinder walls re-coated with nikiasil (spelling?). Once back, the words clean cannot be overemphasized. Wash it extremely well with Dawn soap and then dry, when you can rub the inside of the cylinder with a piece of white paper as if it were sandpaper, and it comes out clean then it is ready for assembly.

During assembly, be sure to use assembly lube. I like the Crane lube, nice and thick with the consistency of molasses.

Why you changing the crank? Unless you are installing a stroker and don't mind wrenching a lot or the crank or bearing is shot, I cannot understand why you would want to split the case.

Instead of splitting the case (unless it is necessary) why not have the heads re-valved with better angling and flowed. You'll get a great bit of ponies out of this mod.

Good luck!

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BATTLEGUN

Discussion Starter · #3 · May 29, 2009

That's the kind of feed back I was looking for GW. We don't "have" to replace the crank as far as we know. I was just thinking while we have it apart, do it all. I see your logic though, and if there wouldn't be enough gain to justify the pain, then I may just skip that.

Maxmud

· #4 · Jun 12, 2009

Make sure you use a company who has a good reputation with bore jobs. I had one done and tried to save a couple bucks, and well, It cost me double by the time we figured out what had happened. You could see the rings wore oblonged the bore was off. Don't ask me how, but it was. Had it bored again, (diff company) and all went perfect.

Bull800

· #5 · Jun 12, 2009

I would try to get it above 686 with up to a 103mm high compression piston, cam and port and polish. Maybe bigger valves to breath but I have not done any research on 660's. My knowledge was on 700's

BATTLEGUN

Discussion Starter · #6 · Jun 12, 2009

Well the mechanic we will be using for this project, Yamaha trained, explained we do not have to split the case to replace the valve. Once we have it opened up to bore, port and polish it, it would be the perfect time to crank it as well.

There doesn't seem to be too many people out there who have done something like this to their 660 that are willing to talk about it. However, I did speak with one reputable racing company/sponsor who said they ran a 660 BB'd to 686 and also 660 BB'd to 7something. He said the 686 ran a lot better and was def the best value to dollar. Let's also consider how hot the 660 motor runs. If you BB to 700+ you are going to end up rebuilding a lot faster I'm afraid.

GRIZZLYWIZARD

· #7 · Jun 12, 2009

There is not a whole lot of difference between the 660 motor and the 700. And, I have hear the same thing about getting the HP out of the 660 as you have described.

I am having a tough time though seeing why a port, polish, bore and piston would be a good time to crank it. Although, if you have the money, patience and time and are not concerned about overall reliability then if you balance and stroke it. Then you are talking some major ponies.

If you are going to do all the head work, you are planning to flow them aren't you? You'll also wanna consider some TLC on the carburetor, there are some tricks you can do to get some great throttle response and believe it or not, you can even get more HP out of the carb vs. EFI.

Hell! I am getting excited about the project and I am not even involved.

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Bull800

· #8 · Jun 12, 2009

Yeah me too! I love to know there are other people out there like me with all the "what if I do this" or "what if I do that". I have always been the guinea pig in my group!

BATTLEGUN

Discussion Starter · #9 · Jun 12, 2009

Well, the main goal is to get it running right now. It had a highly modded airbox lid and a hmf uty pipe. The dang thing had a terrible miss at about 1/4 to 1/2 throttle. Come to find out the carb wasn't getting enough vaccum to operate properly. We're putting a new stock box lid on it with a high flow K&N and pre filter along with a jet job. Also going in as we speak is a Dalton Clucth Kit to compliment the 26" Mud Bugs. Didn't really need a kit in my opinion, but hey, if it gives it more out of the hole then we'll take it. Once we get the thing running right, we'll bust it open and do the fun stuff.

I'm glad I've got some people on here interested b/c I'll be pinging and giving reports as this thing gets going.

Bull800

· #10 · Jun 13, 2009

BATTLEGUN said:
Well, the main goal is to get it running right now. It had a highly modded airbox lid and a hmf uty pipe. The dang thing had a terrible miss at about 1/4 to 1/2 throttle. Come to find out the carb wasn't getting enough vaccum to operate properly. We're putting a new stock box lid on it with a high flow K&N and pre filter along with a jet job. Also going in as we speak is a Dalton Clucth Kit to compliment the 26" Mud Bugs. Didn't really need a kit in my opinion, but hey, if it gives it more out of the hole then we'll take it. Once we get the thing running right, we'll bust it open and do the fun stuff.

I'm glad I've got some people on here interested b/c I'll be pinging and giving reports as this thing gets going.

Sounds great! btw did you ever get the clutch kit in the Outty?

BATTLEGUN

Discussion Starter · #11 · Jun 13, 2009

Bull750 said:
Sounds great! btw did you ever get the clutch kit in the Outty?

Nope. When I get home from this training I will do it. The top speed run I did last week was part of the preliminary testing.

Gunny

· #12 · Jul 9, 2009 (Edited)

Battlegun, just saw this thread today ... Oh boy .... I was think'in about doing this to my 660 this very morning, except ... my motor is still running strong so why mess with it, right ?? :dontknow:

Anyway, here's some things I've heard and one suggestion that I'll be do'in to my 660 next season.

First, I talked to a guy last year who had two Grizzlies, one was out to a 686 & the other one was out 727. He said, in his opinon, the 686 was the better running bike. Sorry, I didn't ask him why.

Now, a friend of mine has an 04 - 660 Rhino which he uses mostly in the sand. He put the 686 kit in first, said his Rhino ran strong & had more torque.
Then, just because, he tore it down & put a 4mm longer rod in it (I think) ... not sure if this brought it out to the 727 but if not, then just under it.
He LOVES that set up. He claims he has a ton more low end, pulls real hard, & still has massive top end ..... and he rides it hard.
His boy took it on a 100 mile desert ride .... ran it for a 50 mile stretch WFO .... no problems !!!
But I don't know what size piston he used ... I do know, it was a "JE" brand.
Also, he didn't change out the cam .... because he hadn't thought about it.

I can ask him what he did, if anything, to the cylinder after boring it, if your interested.

And here's my suggestion .... how about getting the header pipe & the piece to the exhaust can "Jet Coated" ?? :cheer: :cheer: :cheer:
Is the exhaust pipe between the header pipe and exhaust can a seperate piece ?? (It is on my Leo pipe)
I had my exhaust on my Banshee Jet Coated & it's way nice. Always looks clean & runs cooler. :icon_thumleft:

OK, waiting for further updates Big Guy !!!

ccasion14:

Later ....
:seesaw:

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BATTLEGUN

Discussion Starter · #13 · Jul 10, 2009

With everything going on I neglected to update this thread. Sorry.

So far we've put a dalton kit in, K&N filter, closed the airbox, jetted. We are still going to "juice" this up but we are leaning toward the 686 because we've heard more times than not this is the best way to go. If you think about it, the 660's run hot as it is, the more you reduce that wall, the more you're opening up for damage. After all, we won't be racing this quad 2 or 3 times before rebuilding and then racing 2 or 3 times again. We are doing this because the piston rings are obviously failing in the quad and if it has to be opened up, we are going to do it right.

Thanks for your input Gunny and yes, any feedback you can get from others who have done similiar mods is welcomed.

Gunny

· #14 · Jul 25, 2009

Battlegun ... do you have any updates on this project ??

I have some news for you on my buddies stroked 686 kit .... it went South :sad11: .... seems the crank was out of true by as much as 0.006. It chewed the the needle bearing the end of the crank rides on & the crank itself up. :sad1:

He's putt'in a stock crank back in ... along with a turbo he picked up for a $100 ... ;;t;;

And since I picked up a Raptor cam, he wants me to do a 686 kit in my Grizz .... now he's got me think'in !!!! ... and if I do .... I'm do'in the Jet Coating to my pipe ...... WOO HOO !!! :cheer:

So you bess get crack'in dude !!

Later ....
:seesaw:

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GRIZZLYWIZARD

· #15 · Jul 29, 2009

Updates???

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