Quick Primary Spring Question - Clutching a 700

[94fordguy]

So on my 09 700 I am thinking about changing spring colors next season.

What I have now is a black spring labeled as a 140/330.

What I am thinking is that I would like to put in a black/green 120/340 spring to lower my engagement RPM a little bit.

What I am wondering is - what will the slightly higher finish rate do for me?

Throughout this season I have had a little bit of belt squeal at idle when it gets warm which I am attributing to the belt deflection being just a touch on the tight side, but I have also noticed at times that it will squeal at slow moving speeds as well.... something I would not think would be noticeable after engagement with simply running the belt too tight??? Could the current spring be too stiff at slow speeds?


So far I have 600 miles on the belt and it still looks good, despite getting hotter than the surface of the sun when riding hard

Thanks for any input you might have

 

[chunkysoup]

So on my 09 700 I am thinking about changing spring colors next season.

What I have now is a black spring labeled as a 140/330.

What I am thinking is that I would like to put in a black/green 120/340 spring to lower my engagement RPM a little bit.

What I am wondering is - what will the slightly higher finish rate do for me? It would raise your peak rpms a little but not by much.

Throughout this season I have had a little bit of belt squeal at idle when it gets warm which I am attributing to the belt deflection being just a touch on the tight side, but I have also noticed at times that it will squeal at slow moving speeds as well.... something I would not think would be noticeable after engagement with simply running the belt too tight??? Could the current spring be too stiff at slow speeds? Yes or your weights are not quite heavy enough. Could be a sticky clutch as well.


So far I have 600 miles on the belt and it still looks good, despite getting hotter than the surface of the sun when riding hard Sounds like you need heavier weights. Running the weights you have and raising the finish rate of your spring will only make the clutches hotter.

Thanks for any input you might have

Answers in red. hope this helps.

 

[retiredpop]

Have you taken the belt off and scrubbed it in really hot soapy water with a stiff bristle brush? It may look okay but very likely it is glazed. Also do the same with the primary clutch to get the belt residue off the sheaves. While you have the clutch off you can clean the weight pins and rollers etc.

 

[winter brew]

If all you want to do is lower engagement you are on the right track....If a sleds peak RPM is already correct and all they want is a lower engagement I usually recommend dropping the initial spring rating down while raising the "full-shift" rating about the same amount....this will keep RPM close to the same in the shift range we spend the most time in.....not until almost full shift will the higher rating have any effect.

 

[94fordguy]

Thanks guys....

About the only thing I can add is that I don't really want to go to heavier weights if I don't have to as I like the way the motor spins up quickly, and perhaps with some combination of heavier spring snow and 600 miles on the clutching, I have noticed a small drop in peak RPM... it's running right around 8K instead of 82-84 with the SLP pipe that I was seeing earlier in the year.

To be honest, I am not even sure what weights are in this thing at the moment... I just know most of the season it was running 82-8300 on the climbs and life was good other than the slightly higher than I like engagement.

 

[94fordguy]

I did some looking at the sled yesterday and found out that I am running 10-60 weights in it along with that 140/330 black primary spring. I would like to drop the engagement as mentioned with the use of a 120/340 black/green spring. Would I be helping myself more to also go to 10-62 weights? I don't want to get away from the 8400 RPM I was seeing at the beginning of the last season though.

Last year I was running 19:42 gearing and I still had more trail speed than I need so I swapped to a 18 top to get me 18:42 hoping for more torque where I can use it.

I just don't want to screw up changing 3 things at 1 time and lose power in the process... Is my train of thought here correct or should I keep the weights the same... I am currently averaging 38-40MPH track speed and would like to gain more if anything... and I do have an SLP pipe on the sled.

THANKS!!!!!!

 

[diamonddave]

Seth, I have tried the 18 tooth top sprocket on an 08 700. No good!!! The 19-42 tooth combo is dead on nuts perfect for this sled and our area. to run the 18 tooth successfully, you will need to completely re-clutch with a different philosophy.

Given what you are trying to accomplish, I'm not sure throwing more weight (stock series 10's) is going to produce the results you are looking for. A change in the type (or brand) of weight would definately help for giving you a little more pull off the bottom and better, mid range without sacrificing top end. A heel heavier weight works much better than the series 10 weights do on the small block CFI's.

For me, to this point, the belly buster weights Carl's sells accomplish this. Some guys like the SLP weights. This year I am going to be trying the MDS weight's (adjustable).

The other thing the 700 CFI desperately needs for clutching is a different helix. Carl's has a proprietary cut helix designed specifically for your application (piped). This helix will give your sled much better low end and midrange performance with much lower belt heat when in the deep. I know you will find what you are looking for. I have installed and tested a couple of these on 700's not to mention 685's, 660's and 800's. The combination between their weights and helix and the pipe you already have will make that sled perform like it should and will compliment each other.

 

[94fordguy]

Thanks a lot Dave, I will look into those for pre-season

I take it the 60 gram BB's would be the correct replacement for my 10-60s right?

 

[NapaMatt]

Thanks a lot Dave, I will look into those for pre-season

I take it the 60 gram BB's would be the correct replacement for my 10-60s right?

Yes, your correct..

60 Gram.. BB = 10-60 polaris weights..

 

[94fordguy]

Well my new 60g EPI BBs showed up as well as the new helix, but seeing as it is a twin track helix, which track should I start out with?

It lists 60-40.40 and 62-38.40

I really don't know a whole lot about how helix angles work, lol

Thanks again!

 

[volcano buster]

I've got a Carl's 60-40-45 in my 660. I would start there I guess.

 

[diamonddave]

Seth, have you had a chance to install and test your new set-up?

 

[94fordguy]

Seth, have you had a chance to install and test your new set-up?

Everything is installed and ready to ride, I've just taken my 900 the first couple trips this season, haven't had the 700 out... frankly I've been waiting for the snow to settle a bit and to get a good base to cover up the rocks and stumps. I noticed riding it up the driveway that this new clutch setup dropped me from 4400 engagement to 4K engagement, I am thinking I am going to like that, time will tell how the whole package change performs.

 

[culvert]

Where can I get more info on this kit from Carl??
Just picked up an 07 D7 155. SLP pipe, HPS can, running around 2200'
Pri Silver spring, 10-60
Sec havent opened it up yet to see the spring but stock helix.

Going to take it for the first ride this wknd.

I havent seen anyone mention a silver spring so not sure what its going to do.
Short rips I have tried I was getting 83-8400 RPM. So I know I will need 62 in it for local riding.

Thanks for any help or tips.

 

[94fordguy]

Seth, have you had a chance to install and test your new set-up?

Got the 700 out today, actually as a loaner for one of my buddies who had an unfortunate incident with his sled first thing this morning (nothing major)

Sled ran really strong as I was expecting, Engagement was extremely smooth and the sled pulled VERY good for a lil 700. I didn't watch track speed very closely, but I think it was close to 40mph, it pulled good The only issue I am having is that I'm not getting quite enough RPM out of it, we were seeing 8K consistently with spikes around 8100 or so - Max recall showed 8300 but I think that was after a couple wheelies.

I'd like to get it ripping back up to the recommended 8400 if I can, but other than that, the sled ran AWESOME and I have absolutely no complaints, I love the new clutch/gear combo for the little time I had to ride it. I did notice the RPM never fell off, it back-shifted very well.

I've got:

SLP pipe/can
60g EPI Belly Buster weights
Black/green 120/340 spring
Carls twin helix in 60-40 .40 position
Stock secondary spring (not sure which it is)
18/42 gearing

Thanks

 

[94fordguy]

Another update.

I've got about 150 miles on the sled this season with the new clutching and gearing. I LOVE the 18/42 gearing, it's providing extremely positive launches and still has longer legs than I do... I had it up to 73MPH and still accelerating when I backed out of it on a flat trail this weekend. The throttle is also extremely responsive, what it lacks in 'big block torque' it makes up for in snappiness. Engagement has dropped from 4400 to 4000 RPM with the BLK/GRN primary spring and seems to be a tad smoother as well. No bog or ill effects from the spring change either

The only issue I'm having is with peak RPM, the sled is only pulling about 8150 RPM consistently on the climbs (with higher spikes) and I want to get that back up to 8450, I'm thinking 58g weights will solve my issue there. In the snow we've had the last few weeks it's been pulling a consistent peak of 38mph which is what I was seeing last year, but I think I'll be able to pull 40mph if I can get that extra 300 RPM I'm looking for. Engine braking on the descents is very very good with the Carl's helix, I almost never need to use the brake lever and there is no fall off in RPM while climbing, it appears to be back-shifting just fine. I'm not too sure how clutch/belt temps are as I hate having to get out a screwdriver to take these stupid side-panels off, lol.


I'm not sure if or when I'll get the weights changed out as cash is tight, but wanted to give a detailed report on my experiences so far with all the changes.

 

[volcano buster]

Waiting to hear what you come up with to get your top rpms where you want them.

As for the side panel access. Mine was a Carl's assembled sled so it had the tricks on it. They just use standard hardware thumbscrews with a washer and an undersized rubber washer under the metal washer to hold it on. This will make sense when you pull the thumbscrew out and drop the washer in the snow. The rubber washer holds it all together.

Bad picture, but you can see it in the corner of the picture.

Options:
http://www.mcmaster.com/#thumb-screw-fasteners/=l9fgxl
http://www.mcmaster.com/#thumb-screw-fasteners/=l9fh4i
http://www.mcmaster.com/#thumb-screw-fasteners/=l9fhhy

 

[ripalip2]

your clutch tool also has the same thread as the nut that holds the side panel on , pick up another tool and put a nut on it at the top of the threads an screw it in the hole , works great and the clutch tool is always handy

 

[volcano buster]

Have you made any additional changes?

 

[94fordguy]

Nope, I haven't had the 700 out since my report and no significant new snow is forecast. I also haven't decided if I want to shell out another $120 for another set of EPI weights (58g) or just go back to 10 series in 58g for about half the price. The sled is a BLAST to ride and is incredibly snappy, just a touch low on the top end is my only issue. I do LOVE that 18/42 gearing feel!

Example - 3 weeks ago when we were riding in spring like snow conditions the track hooked up so well the sled damn near threw me off the back end it accelerated so hard as I was coming out of a ditch onto the trail I only wish I could have got it on video, lol.