2003 800 RMK losing power after a few minutes

[TroyS]

Yesterday i went out by myself and enjoyed some of the seemingly bottomless powder we've got right now.

I had a problem though. once i got up the "trail" (one track through the new snow) and to the area where i started playing and boondocking, i would start to lose power after a few minutes of playing.

The first time it happened scared me because it was at the top of a particularly long full-throttle pull. I was just starting to think to myself, "man, this is a long pull, gotta be building some serious heat." Of course as soon as i thought that the engine started to lose power and i figured i was starting to seize.

Well i don't think it seized, it pulls over smoothly and after sitting for a while and cooling down, it ran just fine. So i shrugged and went back to riding. But every several minutes the same thing would happen. Lose power, sit, wait, go fine again.

So now i wonder if my carbs were icing up and sitting allowed them to thaw out again. THere was a little bit of snow in the airbox.

Here's what i'm running:
03 800RMK stock engine
SLP single pipe
SLP intake

I had some problems last time out that i thought may have been water in the fuel, so i added some ISO Heat brand fuel additive that is supposed to absorb water (isopropyl alcohol). Then when i went to fuel up, everyplace was closed except the Arco station, which i typically avoid due to rumors of sub-standard fuel quality. Since I had to get Arco gas, i also dumped in a little octane booster. I put in about 5 gallons of the Arco gas which was labeled as being up to 10% ethanol. And i had maybe 1/4 tank of 92 octane ethanol-free fuel from the last ride.

So i had quite a cocktail in the gas tank.

Other than carb icing, my dad suggested possiblities of clogged intake or exhaust. My sled does not have the little deflector on the bellypan in front of the exhaust, i'll have to make one and rivet it on. I also have only the stock intake vent. The foam mesh by the steering column was usually caked with snow. I was carrying a foot thick layer of snow on the hood most of the time.

Snow was awesome, and when it was going, the sled was going good! What was wrong?

 

[mn2mtns]

Could be a few things but my guess is either pipe going out of tune from a lot of heat in it being it was after long pulls or snow/ice buildup on air intake. The intake is the easy one to fix so go there first. I have had both issues myself. Clean air intake often and clean the hood vents often in those conditions to keep the pipe a little cooler. Hope it helps.

 

[theultrarider]

x2^^^^^

Start with getting the slp intake vents for that slp. They are a must have for dry light fluffy powder days or you will suck water through your foams all day. Start with that and the exhaust deflector. C;ean the snow off your hood often and open it up to let things cool every 30 min or so. Your belt will love you for that.

 

[snowmobiler]

the intakes filters are plugging dudeif it ran good on the trails,you could either live with it and wipe it off like i do or get some of these ...........
http://www.startinglineproducts.com/catalog.cfm?pageID=detail&catalogID=3&catID=21&productID=356
might need to jet a little richer if you add air.

 

[TroyS]

Alright cool, i'll try some more venting and pre-filter screens first. Hopefully that's all it is.

Thanks.

PS - i did burn up a belt too, it actually melted a bunch of rubber onto the primary clutch which i then had to try to scrape off without scratching up the surface of the clutch... that was a pain in the butt up on the mountain in the snow and with limited tools!

 

[snowmobiler]

burning belts are from getting stuck

 

[theultrarider]

I ride a twin to yours wife and kid also have edges and have several freinds with edges as well. When you do the prefilters and the flow rites ( which make a huge difference) you will have the take the air plenum shelf off of the inside of the hood. This is the perfect time to inspect the foam gasket that goes around the headlight to make sure that it is intact. About half of our sleds start falling out to some degree. Since you have it apart, I would take a caulking gun and seal it up well from the inside. 2 beads of silicone, foam to the hood, and foam to the headlight. Nothing worse than having a glorious powder day and having to stick to others tracks cuz your sled whats to bog down everytime you stick your nose in it!!!

 

[TroyS]

burning belts are from getting stuck

I get stuck a lot, hasn't been a problem before... It does make some sense though, since i had packed down the snow and was just trying to crawl out of my pit (which worked). That is my usual practice and generally i don't slip the belt enough to cause any trouble. Maybe yesterday i was slipping it more than usual? Or maybe the clutches were hotter than normal? The hood vents were all covered pretty much all the time.

When you do the prefilters and the flow rites ( which make a huge difference) you will have the take the air plenum shelf off of the inside of the hood.

You're talking about the SLP part that seals the airbox so that it draws only from the single vent on the left side of the dash next to the handlebar stem, right? I was wondering about that when previous posters suggested the vent kits, I don't see how adding vents to the dash would help if the airbox is can't draw air from inside the engine bay anyway.

DO i want to draw air from in the engine bay, wouldn't it be hotter, and less dense, giving less power?

 

[94fordguy]

A couple thoughts...



Your power valves could be dirty, how long has it been since they have been cleaned?

How long has it been since your clutch has been serviced? Bushings could be wore out and clutch could be not shifting properly creating more load on the engine, if you are hitting 8100 RPMs you should be in the ballpark tho,

How hot did you get that sucker I've never heard of a belt actually melting to the clutch! How much life do you typically get out of a belt?

If you are building that much heat under the hood, some vents might be a good idea, but it doesn't explain why you are building that much heat...

 

[TroyS]

Just cleaned the power valves a few weeks ago. Have not serviced clutch. I guess i'll have to learn how to do that, there are probably good threads on this site about that. I don't really know how hot it was getting, or even if it was getting abnormally hot. How can i tell?

I got the sled last spring with a 144" track (stock) and rode a couple times mostly in firmer spring riding conditions, ran a little rough the first time out (old fuel) and fine after that.

During the summer i added a 159" track and tunnel, PERC reverse kit (came with new TEAM secondary clutch) and a custom seat.

Prior to that my riding was usually on my dad's 2002 800RMK with similar setup + vforce reeds, and i think maybe some extra venting, and with a mechanical reverse.

 

[theultrarider]

.




You're talking about the SLP part that seals the airbox so that it draws only from the single vent on the left side of the dash next to the handlebar stem, right? I was wondering about that when previous posters suggested the vent kits, I don't see how adding vents to the dash would help if the airbox is can't draw air from inside the engine bay anyway.

DO i want to draw air from in the engine bay, wouldn't it be hotter, and less dense, giving less power?[/QUOTE]

I'm sorry, I wasn't very clear. Yes that whole piece that the slp airhorn rivets to under the hood comes off with about 10 screws. This must be TEMPORARLY removed to clean the junk out after drilling the hole for riviting on the intake screens and for the big holes for the flow rites. After cleaning everything up, you will re-install the plenum. You are right, you want to be drawing cold outside air. The dash area IS one wall of your air intake, so any and all hole in the dash area create more air entrances into your intake.

 

[TroyS]

Ah, gotcha theultrarider, thanks .

I'm gonna head into town now to pick up a new belt or two and see about getting some silkscreen material. I was looking around thinking it's probably not really necessary to spend a bunch of money on SLP stuff if i can find that material and make my own vents. Found this thread where it sounds like they found that a fine-grade silkscreen material is the same as the SLP screen. If i can get a bunch cheap, then i can add lots of good vents. I really shouldn't be putting much money into the sled right now, given how the economy has affected my cash flow.

 

[TroyS]

Well i couldn't find any screen material locally so i popped for a pair of 2.5" round vents and stuck them in next to my guages. I think i might also wrap some pantyhose material around the OEM foam blocks before i put them back. Good idea?

also got a new belt for $80! Ouch.

Probably will ride tomorrow, hopefully things are improved.

 

[anchsand_darryl]

I have a 2000 800 and the mag side carb will ice up if i get out in the deep stuff or try and put muy way through the jungle of spruce , it will run fine flat out or on the trail(that sucks) sled ran fin for the first 3000 miles then started this crap rebuilt it at 3200,new pistins rings reeds ect , checked carbs they seem fine???????????