Cheater Head Questions

DaFuzz · Sep 28, 2009

I recently purchased a used 2003 RMK Vert Edge 700 151". The previous owner was the second owner of the sled, so minor mods were completed prior to him having the sled. He said he thinks the parts that aren't stock are a PSI Fat Pipe single, an SLP cheater head, and it also has an SLP airbox/airhorn with both flowrites by the gauges and screened vents on both sides, near the bottom of the hood. Other than that, the sled appears to be stock and in very good condition with about 2700 miles.

I posted a couple pics on snowmobile fanatics, because I couldn't get them to work on here, with pics of the pipe for identification purposes, and people there have told me its a PSI or Aaen pipe. I pulled the head and it does have an SLP cheater head, with domes marked 12-543pto/mag, which also look to be in very good condition, and the cylinders look good too, cross-hatch marks intact and no scratches or grooves at all. The compression on both cylinders is between 140-142, wot, 6 pulls with both plugs out, so that appears to be good, at least for a stock engine.

This is my first real sled, I've always had beaters or smaller stock sleds, so I'm totally unfamiliar with the cheater head. I've always fixed stuff, and have had a carbed 1000cc bike that's far from stock, so I'm somewhat familiar with carbs, jetting, stuff like that, but just not on sleds, and not clutching like on a sled, either. I'm wondering if I'll be able to use this head/pipe combo at my altitude of about 900-1100 feet, this sled was always trailered out west and only ridden in the mountains before I got it. I haven't pulled the carbs to see what it's jetted at yet, I first wanted to see if I need to look for a stock head or if this cheater setup will work with pump gas. I've run the sled twice, only at idle to check it over a little before I bought it, it seemed to run fine, and didn't smell like it was way rich or lean.

My questions are: Can I use this cheater head and pipe combo at my altitude without having to mix fuel/race gas/100ll? I want to be able to fill at the pump, premium if needed, but don't want a sled that I have to mess with all the time. What should I be looking at as far as clutching and jetting? Is this enough compression for having this cheater head installed, or is it low for a high compression head?

Thanks in advance, and sorry that it's a little long-winded. Scott

Kraven · Sep 28, 2009

DaFuzz said:
I recently purchased a used 2003 RMK Vert Edge 700 151". The previous owner was the second owner of the sled, so minor mods were completed prior to him having the sled. He said he thinks the parts that aren't stock are a PSI Fat Pipe single, an SLP cheater head, and it also has an SLP airbox/airhorn with both flowrites by the gauges and screened vents on both sides, near the bottom of the hood. Other than that, the sled appears to be stock and in very good condition with about 2700 miles.

I posted a couple pics on snowmobile fanatics, because I couldn't get them to work on here, with pics of the pipe for identification purposes, and people there have told me its a PSI or Aaen pipe. I pulled the head and it does have an SLP cheater head, with domes marked 12-543pto/mag, which also look to be in very good condition, and the cylinders look good too, cross-hatch marks intact and no scratches or grooves at all. The compression on both cylinders is between 140-142, wot, 6 pulls with both plugs out, so that appears to be good, at least for a stock engine.

This is my first real sled, I've always had beaters or smaller stock sleds, so I'm totally unfamiliar with the cheater head. I've always fixed stuff, and have had a carbed 1000cc bike that's far from stock, so I'm somewhat familiar with carbs, jetting, stuff like that, but just not on sleds, and not clutching like on a sled, either. I'm wondering if I'll be able to use this head/pipe combo at my altitude of about 900-1100 feet, this sled was always trailered out west and only ridden in the mountains before I got it. I haven't pulled the carbs to see what it's jetted at yet, I first wanted to see if I need to look for a stock head or if this cheater setup will work with pump gas. I've run the sled twice, only at idle to check it over a little before I bought it, it seemed to run fine, and didn't smell like it was way rich or lean.

My questions are: Can I use this cheater head and pipe combo at my altitude without having to mix fuel/race gas/100ll? I want to be able to fill at the pump, premium if needed, but don't want a sled that I have to mess with all the time. What should I be looking at as far as clutching and jetting? Is this enough compression for having this cheater head installed, or is it low for a high compression head?

Thanks in advance, and sorry that it's a little long-winded. Scott

2010 SLP Catalog says part # 12-543 heads are for 0-9000' altitude for use with stock pipe or SLP single

or

6000'-9000' with twin pipes.

NO race fuel / mix for either set-up

I can't see the Aaen/PSI pipes having a greater affect than the SLP single, (perhaps someone else could chime in) so would would probably be O.K. for straight 91 octane.

Doesn't that Vertical Edge have a DET sensor,??? I know that the DET sensor didn't find it's way into the short tracks until 2004, but somehow remember reading something about the Vertical Edge getting it in 2003, NOT sure however??? If so that would provide some additional insurance.

Hope this helps

DaFuzz · Sep 28, 2009

Yes, the 03 VE has the DET sensor, I've never rode a sled with that sensor before, does that mean I can just use the regular unleaded 87 octane pump gas, or should I use the premium as cheap insurance?

I just pulled the carbs and they have 290 mains in them, which appears to be for 30-50f at 8000-10000 ft. I will definitely need to re-jet, it's just a matter of what size to use? I ride around 1000 ft, with temps generally -10 to +20f, so from the stock jetting chart, it looks like I should be around a 450-470 main jet size? But that charts for a stock sled, stock head, stock exhaust, stock intake. Now that I have all the part numbers and what jets in it now, I'll call SLP tomorrow and get their recommendation on jet size, but any help from you gurus on this site would be greatly appreciated.

Next question, what should I be looking at as far as clutching? I've never messed with clutching on any sled, so this'll be a little new, but may be a huge improvement over whats in it now. What info do you guys need to know whats in it at the present time? If the jetting is for 8-10000 ft, I'm guessing the clutchings gonna need a little work, too.

mod03rmk800 · Sep 28, 2009

Slp's jetting from my experience is VERY safe(fat). I would talk with bikeman maybe. I think they are in the low elevations?

deere1 · Sep 28, 2009

You might shoot SLP and e-mail and ask them about jetting, clutches, and gears. Keep it as brief as possible explaining your sled and riding conditions. They have given me good advice over the years. Although I also agree they are usually a little fat on jetting requirements. But they will give you a place to start.

Kraven · Sep 29, 2009

deere1 said:
You might shoot SLP and e-mail and ask them about jetting, clutches, and gears. Keep it as brief as possible explaining your sled and riding conditions. They have given me good advice over the years. Although I also agree they are usually a little fat on jetting requirements. But they will give you a place to start.

x2 on calling SLP, they've always been super helpful over the years

Tech line (208) 524-3397 tell the receptionist you have a tech question on clutching and jetting and they'll get someone that's qualified to answer your ???????

Agree with the above posts^^^^ that SLP is overly conservative on their jetting, but that should get you off to a good starting point.:face-icon-small-hap

Fuel: use 91 octane, do not use the cheap stuff, it's not worth the risk

DET sensor, it's mounted on the bottom side of the head, near the t'stat. When it senses engine knock it begins to retard timing, first a little then more, can't remember if it's something like 2*, 4* then stutter mode if I remember correctly, a warning light should also go on????, on the dash,

I noticed you're from Northern Wisc, if you're considering taking the sled out West once in a while, I strongly reccomend a Holtzman ATAAC, automatically adjusts fuel for altitude and temp changes , best $245.00 mod you can find, I.M.O. www.holtzmaneng.com

I use to run the ATAAC's on 2 of my own sleds and 3 of my buds, we usually ride Northern Wisc and the Western U.P., but run out to Yellowstone every 2-3 years or so, we're long overdue.

Regarding the pipes if they were Aaen, I remember that name being stamped (actually protruding outwards) on the pipe somewhere, if that's the case maybe some one has some jetting specs for it???? Other than that ditto for P.S.I.

Another option to simplify things so that you're not jerking around all winter trying to dial it in is just find a stock pipe (should be plentiful put up a post here on SnoWest, probably $100 or less), install that, leave the SLP cheater head on, install the stock jetting and clutching and enjoy RIDING it, rather that working on it all season.

Hope this helps

DaFuzz · Sep 29, 2009

I had remembered seeing something strange looking in the airbox, so I went and looked, and the sleds already got an ATACC installed in the airbox, I just didn't have any idea what it was when I was pulling the carbs to check the jet sizes. So now that throws another spin on this sled. The guy I bought the sled from didn't even mention that it has an ATACC in it, which is a little unusual, given the price of the ATACC, he must not have even known it was there. So that's pretty cool.

DaFuzz · Sep 29, 2009

I just got off the phone with SLP, they recommended using a 510N main jet, which they said is the same as a 540, which is off the charts fat, so what do you guys recommend?

According to the stock chart, it recommends a 490 for -10 to -30 f at 0-2000 ft. With the Ataac, would this be a good starting point, or should I start at 470?

Kraven · Sep 30, 2009

DaFuzz said:
I just got off the phone with SLP, they recommended using a 510N main jet, which they said is the same as a 540, which is off the charts fat, so what do you guys recommend?

According to the stock chart, it recommends a 490 for -10 to -30 f at 0-2000 ft. With the Ataac, would this be a good starting point, or should I start at 470?

DaFuzz,

Great news on the ATAAC,

As far as jetting goes, you're better off starting rich than lean so I think you know the answer there.

Coincidently, I ran the 510 N in my 2002 800 with minor bolt on mods (in my signature) Stock pipe on an 800, and you're aftermarket on a 700

Regarding the"off the carts fat" Keep in mind that the 510N is the next size RICHER than a standard 500, a standard 520 is like a 495 (sounds weird but somehow there's a gap/mix-up in the system) . Here's the article published in the March 2009 issue of SnowTech that explained all of this:

MAIN JET **** EQUIVALENT ** FUEL FLOW (G/MINUTE)

400 ------------------------------- 352
420 -------------------------------- 372
440 -------------------------------- 392
460 -------------- ------------------ 410
480 -------------------------------- 430
500 -------------------------------- 453
510N = ====== 540 *************** 466
520N = ====== 560 *************** 481
530N = ====== 600 *************** 491
540N = ====== 620 **************** 515
550N = ====== 660 *************** 538
560N = ====== 700 *************** 572

Regarding the ATAAC, jet for minus 20 at the lowest base elevation (Northern Wisc in your case) that you're going to ride at and you're done.

Hope this helps!!

DaFuzz · Sep 30, 2009

I jetted for -20 f in WI, 0-2000 ft, using a 490, so we'll see how that it, it should be good with the ATAAC. I'll throw the head back on tomorrow and it'll be all back together and ready for snow, now if it was only mid november, I'd be happy. Geez, that's a long ways away. I wonder how far I'd have to trailer to find snow in early October? Thanks to everybody for your input and advice, I love how active this sled forum is!

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Cheater Head Questions

DaFuzz

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