02 RMK 800-high idle problems

frozen north · Sep 28, 2008

I need help, I have high idle problems, The motor has high comp head, bored carbs to 41.5, 2" riser, gutted air box. The sled starts just fine. but will not idle down. I have tried to adjust the idle with the big screw on top-no help, I looked at the cable where it attaches to the carb plate-there is a little slack-not much. When you give it a little choke , it idles down but not for long. 2800 to 2900 rpm is to much.

Anybody have any ideas??

AKSNOWRIDER · Sep 28, 2008

frozen north said:
I need help, I have high idle problems, The motor has high comp head, bored carbs to 41.5, 2" riser, gutted air box. The sled starts just fine. but will not idle down. I have tried to adjust the idle with the big screw on top-no help, I looked at the cable where it attaches to the carb plate-there is a little slack-not much. When you give it a little choke , it idles down but not for long. 2800 to 2900 rpm is to much.

Anybody have any ideas??

sounds like you have a vacuem leak..weather it is a carb boot, gasket or crank seal .take some wd-40 and put the little tube on it and spray around cylinder bases,case halfs and crank seals,as well as carb boots..when the idle comes down like when you flip the choke on you found it...might also check the carb slides..could have broke the lower corners off them......

sled_guy · Sep 28, 2008

Your idle circuit is lean. Could be a leak as AKSNOWRIDER suggests, but likely just a carb adjustment issue, especially if you are running the same settings as before you had the carbs bored.

On the 02 RMK carbs there are 2 adjustments available, one for air and one for fuel. I would try turning the air screws in 1/4 - 1/2 turn to see if that helps. You can turn them in to about 1/4 turn without issue, I don't like to go any further in than that though. You may end up having to change idle jets.

You can give it a little more fuel on the fuel screws, but it has been my experience that can affect part throttle performance where the machine will develop a stumble or gurgle.

sled_guy

frozen north · Sep 28, 2008

I just completed the WD 40 test. No change. I spayed everywhere on the carbs-gaskets-cyl head-jug base.

I will try sled_guy sug-
Thanks guys

frozen north · Sep 28, 2008

Does any one know where I can download or schmatic of these carbs at???

MNIQR · Sep 28, 2008

Heres a pic from the 800 rmk manual i have.

cascadesnowjunky · Sep 28, 2008

If it has been sitting very long it could have some varnish in the pilot jets it dont take much, but from what you describe its definetely lean at idle. I would pull the carbs and check it out if it were me. Mine will do what yours is doing when I start it at home 700ft above sea level but perfect at 4000 ft and above.

frozen north · Sep 28, 2008

I just pulled the air box-adjusted the air screw 1/4 turn-(no luck)-adjusted the fuel screw-2 times-1/4 turn both ways- idle came down to 2600 rpm. I will half to pull them out- check the slides corner like aksnowrider-and the pilot jets LIKE cascadesnowjunky suggests!! YOU GUYS ARE AWSOME.

What is the correct settings for the air screw and fuel?

theultrarider · Sep 28, 2008

The adjustment is different on every sled, especially when you change evelevations and temps. You can turn your air screw in as far as being ony 1/4 turn out....and out as far as about 3 turns out. Any further in either direction, and it is time to change the pilot jets inside the carb. The fuel srew is about the same story. Most stock sleds run about 1 turn out on the air screw and about the same on the fuel screw. Turning the air screw in richens you up, turning the fuel screw in will make you run leaner. As for getting it to idle better, than is more of a function of the air srew, which is the little brass screw that you find inside the end of the airbox when you take it off. The plastic knob one on the side of the carb is the fuel screw. Good luck and let us know if you get it to run correctly.
Tim

AKSNOWRIDER · Sep 28, 2008

FN if you pull the carbs to look at them..pull the rubber adapters that cover the reeds..dont think it would but maybe it ate a reed..also really inspect the rubber adapters looking for cracks....

frozen north · Sep 29, 2008

OK- I just pulled the carbs- pulled the carb boots and reeds out-
Reeds look real good-
1. Carb boots look ok, did find 1 tear (small) on the inside of 1, and 3 (small) ones on the inside of the other, all where located on the inside of where the hose clamp is. They have not wore threw tho.
2. Checked the slides-this is the VM40 carbs I'm told- but bored to 41.5? they do look a little wore but not bad.
3. The air screws were out at 1 1/2 turns-fuel screws out at 1 1/4.
4. Main jets are 410 on clutch side and 430 on the other.
5. looks like the slides go almost all the way down.
6. I did notice the 2 little vent hoses that are connected to the air box from the carbs are ok and connected good.
7. Elevation here in town is about 2600 ft- We sometimes ride to 7500 ft.

HELP--------ANY IDEAS????????????

frozen north · Sep 29, 2008

I FORGOT TO MENTION ON THE SLIDES. They look ok except for the very bottom of these. They look a little wore and some parts look like they have vertical wear marks.
not bad but noticable.

frozen north · Sep 29, 2008

SnowRider1 · Sep 29, 2008

High Idle

I had the same problems on my 04 700 after i had added the Holtzman ATACC system. The only way to slow the idle down was with the choke. I had to adjust on the fuel and air screws both to finally get it right. I had tried a richer pilot jet, but it blubbered real bad. As stated above, each sled responds different to the turns of the screws. Just keep trying and turning. HTH! Kurt

frozen north · Sep 29, 2008

I just checked both carbs out- checked ok-found 145's in both bottoms also-I presume this is the pilot jet? And a number 45 on the fuel jet(very small screw). Found no tarnish-looked real clean- put everything back together-fired it up-air screws at 1 turn out-fuel screws at 1 turn out-rpm at 2550. I will try snorider1 sug about playing with it more. It's just frustrating.

frozen north · Sep 29, 2008

it works-adjusted the air screw in to about 1/2 half out - and fuel screw out about 1.

RPM NOW IS AT 1550 TO 1600.

Does that sound right!!
How about the jets- is this setup ok???

hilinerider · Sep 29, 2008

i still think its a crank seal?

frozen north · Sep 29, 2008

I did spray it down again with WD40 before I pulled the carbs- spayed the crank twice just to double check. no diff in RPM. tHE AIR SCREWS SEEM TO WORK.

hilinerider · Sep 29, 2008

fuel pump line?

theultrarider · Sep 29, 2008

Someone should have asked this question by now myself included, is this sled new to you??? Did it ever idle correctly and it have changed for no apparent reason? Or did this start after you added a new mod of some kind? If this happened just sitting over the summer, you need to find a problem. If it has run fine until you added a mod, you are probably fine now, you just tuned it in. Same goes for if you just bought this sled and it has run like this since you bought it.

02 RMK 800-high idle problems

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