Going from a 600 to a 660.. Missing any thing..

[Chern_889]

From what I have experienced via Carls setup on my '07 RMK 600:
685cc requires case machining
660cc does not require case maching

ECU = not sure on the CFI-4's but on the new 2 injector setup, YES! They haven't updated their site for the 660 CFI kits, still lists the carb'ed upgraded kits. The auto tune may be the way to go and quite honestly, I might get one as well. I'm going to start with an AFR gauge to see how lean/rich it is and go from there. Carls hasn't tested the new CFI-2 660's at low elevation, only the 5-8k elevation. I would call up a few places that offer big bore kits for the CFI-4's and see what they have to say about fuel mappings.

Like you said, you only want to do it once. Now is a great time to call the vendors and get things lined up before the snow flies.

Post up some pics when you get the project rolling.

I assume you don't have the cases apart.

When you set the cylinders down on it you push them back towards the intake and hold them there as far as they will go.

Buy the recommended Carl's clutching, it works.

sled_guy

There is supposed to be a trick to get the cylinders back on without machining the case for the bigger pistons.

Larger air horn for the intake.

Mine has the torque stops, SLP powder valves in air box, venting in the shock wells, and clutching to match.

Dont skimp out!
Do it right and get the cases clearanced!

I bought Jonce's 07 660 and rode it for about 2000miles, at which time i did the top end for preventative maintenance, and found that the cylinders had worked there way foreward! About 2600miles total on the 660 kit.

The bottom 3/4" of piston skirt on the exh side was rubbing on the cases, and looked like it had been doing it for a while. You could not see the damage through the exh port, only once you get the cylinder off. I had to strip the bottom end down and clearance the case myself, and clean the bearings out on the crank. The skirts where knife edged quite badly. I wish i could show you picures, but the pistons are at my parents house. I will see if i can get my dad to shoot some pics for me.

I have since put on another 1600miles since i re did the top end/clearanced the case. No problems to report so far.

Jay

 

[NapaMatt]

Thanks Guys..


Yep.. Ops.. Should of got back to ya sooner..


The the 660 Kit.. Is Getting Fully Ported.. And Case Modded..



I wanted to do it right the first Time!!

 

[Jonce]

Dont skimp out!
Do it right and get the cases clearanced!

I bought Jonce's 07 660 and rode it for about 2000miles, at which time i did the top end for preventative maintenance, and found that the cylinders had worked there way foreward! About 2600miles total on the 660 kit.

The bottom 3/4" of piston skirt on the exh side was rubbing on the cases, and looked like it had been doing it for a while. You could not see the damage through the exh port, only once you get the cylinder off. I had to strip the bottom end down and clearance the case myself, and clean the bearings out on the crank. The skirts where knife edged quite badly. I wish i could show you picures, but the pistons are at my parents house. I will see if i can get my dad to shoot some pics for me.

I have since put on another 1600miles since i re did the top end/clearanced the case. No problems to report so far.

Jay

Good information Jay. I will have to keep that in mind when I get my top end back from Carls and I go to reassemble it. Also, it would be a good preseason check up come next year for me.

 

[NapaMatt]

Just a Update..


Sled Rips.!!!!


Crazy... at 1258 ft Elev

This buggy is Pulling 10-68 bb Weights!!!!

With a 120- 320 primary spring

Black/purple Sec spring 160/240

60/44 .36 helix


Ripping 8350!!

 

[sled_guy]

Another satisfied 660 rider... crazy fun aren't they?

sled_guy

 

[NapaMatt]

VERY MUCH SO!!!

I feel sad for the guys with 660 kits and the engine can only pull 10-64's!! ha ha

Must not of done the whole package if it can't

The 660 Motor NEEEDS Port work PERIOD!!! and porting

Some guys never learn.....

There alot to a 660.. people i think over look..

Yes... i got a lot invested..

But I am Very happy with the outcome!!!

 

[Repsol83]

so what your saying nappa is that i should pull the trigger and do this for this season?

couple questions.

Did you bore the carbs?

What kind of jetting are you running now. I ride in the UP and wisconsin so i think our elevations are close.

I'm also debating if i need to do the v-force reeds and the SLP pipe. I'm just running a stock pipe with sno stuff can right now.

Did you change the springs in the clutching or just the weights?

was the jetting finiky at all?

are your running the oem 700 pistons?

will be having it ported and polished as well. Going to get the ball rolling on this ASAP.. just looking for a little more feedback.

 

[NapaMatt]

Answers in BOLD!

so what your saying nappa is that i should pull the trigger and do this for this season?

couple questions.

Did you bore the carbs? NO, this was a CFI -4

What kind of jetting are you running now. I ride in the UP and wisconsin so i think our elevations are close.

I'm also debating if i need to do the v-force reeds and the SLP pipe. I'm just running a stock pipe with sno stuff can right now.

Did you change the springs in the clutching or just the weights? Springs and weights! and Helix! and Gears! and Chain!

was the jetting finiky at all? NOPE

are your running the oem 700 pistons? YES

will be having it ported and polished as well. Going to get the ball rolling on this ASAP.. just looking for a little more feedback.

answers in bold!

 

[Repsol83]

motors apart... all parts are out for boring / porting etc etc....

working on figuring out clutching and jetting to get the rest of the parts ordered and get it set up for when the parts come back. Should have the stuff in the next week to put it all back together.

 

[Repsol83]

parts finally came... let the fun begin

 

[volcano buster]

I opened the hood on mine and can't figure out where you put those large springs from the left side of the photo...

J/k

Good luck and report back often.

 

[Repsol83]

I opened the hood on mine and can't figure out where you put those large springs from the left side of the photo...

those are for the end line... by the rotary girder

 

[NapaMatt]

hehe haha the Stump Grinder Limited Addition!

 

[Repsol83]

still trying to get this sled running right.... can't figure out a coolant problem.... only warms up to 80 degrees. new thermostat put in... does the same thing with new thermostat... temps warm up when engine is running in reverse. temperatures immediately drop when taken out of reverse.....

 

[volcano buster]

those are for the end line... by the rotary girder

Sounds like you got the springs wound the wrong way!

Good question. Mine was done by Jack so I'm not sure if they did anything different when they pulled the front cooler.

 

[hymarkin754]

Anyone know what year of 700 pistons Carl's uses in their kit? Polaris has different part # for 07-06 and 09-10. A friend bought a 12 660 from a hillclimb racer and it started running bad and hitting DET. I've gone through the entire fuel system with no luck and most of the electrical. Pulled the head and the pistons seem loose, gonna yank 'em and measure things. Should make it longer than 800 miles on pistons I would think, unless the racer was winging some crazy rpms.
Thanks for any help.

 

[volcano buster]

Good question.

I have one that sounds similar to yours. With the clutching that came in it, I could pull 8500-8800 rpms too easy. I had to start playing with the clutching and am still not real happy with it. I am at about 1550 miles with no internal issues yet. I may replace the pistons at about 2000 miles just for fun.

Report back if you find out what pistons they use.

 

[hymarkin754]

I talked to Tim in service @ Carl's today. He said they are stock 700 pistons he said to call the performance side of the shop to get the exact part number. He said that the topend should not be my issue. He said if it hasn't seized that those pistons should go 3000mi. pretty easily.

Volcano, can I get the clutching set-up that you started out with. I'm trying to gather numbers to compare what this sled has.

We've got the stock helix, blk/purp sec spring, stock primary spring, 10-62 weights.

We had no DET tonight so now we're trying to get the rpms up from 7700 max.

We're going to get a new sec spring and through 10-60s at it and see what happens. We're in the 5k-7k elevation range.

 

[volcano buster]

When I bought it, it had the stock helix (58-42-.45), black purple 2nd spring and stock gears.

The primary had an almond round spring and 10-62's. It would over-rev like crazy at my elevation. I have since added a 19-42 gearing, 60-40-.45 helix, Black/Pink primary spring and now have the 10-62's in it again. With this setup, I was engaging at 3900-4000 at 4500' and maxing at 8100 at about 6000'. I know from other spring/weight combinations that this motor likes the 8250-8300 rpms better, but I was fighting over-rev, or sluggish acceleration with those setups. With the current setup, I as playing in the trees last weekend and when I was on a pull and let off to change course, it would struggle to get back up to max rpms quickly. I had to turn out and pick a different line after that so I need to change something.

I'm not sure if I would be better at this point to use a Belly Buster 62, or find some 10-60's or change to a stiffer top end spring.

 

[hymarkin754]

Yeah the SLP blue/pink might be better to get the low end snap back. The 340 finish rate is probably helping keep your rpms up on top though.

Toady we ran the 140/330 polaris primary spring w/ 10-60s. Stock helix and blk/purp.

We were up at 7800-8000ft. Still struggling to get the rpms up. Only seeing 8000rpm on the hill. Going to try to find a used set of 10-58s to try and see if that'll work. Also need to gear it down. It has stock gearing. Also this has a pump has head, don't know what you're running. I think at this elevation we may just have to drop weight. And maybe a blue/pink in the primary.

We had the injectors flowed last week and I think they knocked something out of 'em because no more DET. We had chased that all week. Now we can concentrate on clutching.