[AKCheese]

OK........bottom line my machine is hard to start (like 15 pulls) and it's getting 4 - 5 mpg

the stuff I did (below) maybe helped a tiny bit but last short day out my 500 RMK used 5.5 gallons, my sons 700 RMK used 3

Seems to run "ok" once it's going but maybe a little rough (I'm new at this whole snowmachine thing)

Somebody said......."rebuild your fuel pump"....... I did......

"look for a fuel leak"............NOPE

Somebody else said "check your jets and your needle".......I did......unfortunately they were the right ones/setting

"Clean your carb"......did that as best I could.....I couldn't get the "funnel" off to clean that part.....screws are siezed up

a SM mechanic who came highly recommended told me he didn't have time to work on my sled right now but he said 90% of the time it's the floats........the other 10% of the time it's the choke

the floats SEEMED ok to me but he told be they can look fine and still be bad.....

$150 later I have a new set of floats to install.........

How do I clean/adjust/check the choke?

This is a Mikuni TM38 carb..........the choke cable turns a rod that lifts plungers on both carbs but you can't get at the "guts".......(maybe I could if I could get the funnel off)

The choke lever seems to have "slack" when it's "off" like it should........and it lifts the plungers when it's "choked"...........when the engine is warm it chokes out when you flip the choke "on"

anybody have any recommendations besides putting on the new floats?? (hopefully that's not a waste)

oh yeah........ my plugs go from "new" to BLACK in 15 miles........one plug is a little less black than the other but they're BLACK

on a positive note I am learning a good bit about my machine........and aside from getting crappy mileage it's fun!!

 

[xltier]

my sons xcsp600 ran out of gas at 80 miles from full last week.got it in the shop and found that the rod that goes to the 2 choke valves was sticking due to a little corrosion.that was holding the chokes open a little bit.didnt notice alot of bad performance thou in huindsight it was idling real lazy.hth.

 

[AKCheese]

sorry about that extra reply

I'd be thrilled to pieces with 80 miles *lol*

I peter'd out at 47 from full to the rim!

 

[NewfieBullet]

I think your jetted too rich. How is it running?
I've never gotten better then 10mpg from any Polaris I've owned, and I'm talking Canadian gallons, which would be equal to maybe 8 or 9 mpg american. As far as that goes, I don't think I've ever got better then 12mpg with any machine I've owned.
Generally though, if you're jetted according to temp and elevation, the next step to check is the needle and seat, though that would give you more of an issue when the machine is shut off then when it's running.

I'm curious what you mean when you say the "funnel"?

 

[AKCheese]

I think your jetted too rich. How is it running?
I've never gotten better then 10mpg from any Polaris I've owned, and I'm talking Canadian gallons, which would be equal to maybe 8 or 9 mpg american. As far as that goes, I don't think I've ever got better then 12mpg with any machine I've owned.
Generally though, if you're jetted according to temp and elevation, the next step to check is the needle and seat, though that would give you more of an issue when the machine is shut off then when it's running.

I'm curious what you mean when you say the "funnel"?[/b]

No the jetting is correct..........as is the clip on the needle

The funnel is the "front" of the carb

 

[NewfieBullet]

How are you judging that the jetting is correct? If your plugs are black then it's telling you too rich.

 

[Beaxch]

Well I think he's going by the jet chart. As a beginner, I would not go away from the jet chart unless you have a damn good reason, just be sure you're reading it right for your altitude and temp. Be sure that your main jet and pilot jet are correct if you haven't already. I still think it would start normally even if it were jetted very rich. The plugs should be the same color, the fact that they are different is a red flag, especially if you have a single exhaust (not twin pipes). Well, it's bad either way, but if you have a single exhaust that would affect both plugs equally meaning your problem isn't coming from the exhaust side. Make sure the truly correct plugs are in there - I've seen totally wrong plugs more than I can even believe - BR9ES is not the same as B9ES. But yeah, time for a compression test. Get your tester, warm the engine as fully as possible, turn off the key and/or push the kill switch (very important), take off plugs, install compression tester, hold throttle wide open and give five strong pulls, write down reading. I'm guessing one is going to be 20% lower than the other, or they're both below 100psi.

The other possibility, without looking at your manual, is do you know if your altitude compensation is installed and working? I assume your RMK should have altitude compensation as a stock feature, and if a previous owner removed it you're going to be running way rich all the time. I still think it wouldn't cause hard starting though. First thing I would check is the compression.

Stuck choke is another really good possibility. It might be only or mostly stuck on one side, explaining the imbalance. But would that explain the hard starting? Should make it easy to start.

 

[pyle]

9 mpg max on my 600 xc sp 1500 miles on it that sucks , buddies 600 ho rev 15 mpg tried dpopping needles one notch down in carbs but plugs started burning a little white so i put them back to factory 3rd notch out of 5 any ideas?????????????

 

[Pepsi_fuzz]

I don't know what to say? I discovered my poor mileage was due to riding too slow. The last few times I was out the temperature was awesome, so we were able to ride fast. It took 20L of gas to travel 66.6 miles. That's just over 5 gallons of gas (5.29US Gal). That's 12.59mpg. Which is roughly what I've been getting all along (my math totally sucks). Which means, for the most part, the stock 10.8US Gal tank my Fusion 900 holds can get me at least 130 miles before I'm having a panick attack because I'm running completely out of gas, LOL.

PS riding bellow 50mph renders a decrease of 1mpg. Riding bellow 40mph renders a decrease of 2mpg. Riding above 60mph doesn't affect the mileage until you exceed 95mph, in which case it's starting to struggle to keep the speed up (I would assume the mileage is getting worse; I don't ride that fast long enough to know for sure). If the machine can't keep it's temperature down, decrease another 1mpg added to the decreases mentioned above. At least this is how the '05 Fusion 900 is treating my wallet. The worst my Fusion 900 has seen (using my figures above) is 9.59 mpg, which can only get me 103 miles to a full tank vs 135 miles to a full tank with ideal conditions.

Update: I just travelled 110 miles on the one tank, and I'm not on reserve yet. I would guess that I have just under 1/4 of a tank left (I figure I'm close to 1/8th of a tank, or at least I will be if I just ride it around town a little bit longer).

 

[pyle]

just cleaned plugs again they are black and must be running to rich how can i ajust this ,or should i even mess around with it?

 

[NewfieBullet]

I don't know what to say? I discovered my poor mileage was due to riding too slow. The last few times I was out the temperature was awesome, so we were able to ride fast. It took 20L of gas to travel 66.6 miles. That's just over 5 gallons of gas (5.29US Gal). That's 12.59mpg. Which is roughly what I've been getting all along (my math totally sucks). Which means, for the most part, the stock 10.8US Gal tank my Fusion 900 holds can get me at least 130 miles before I'm having a panick attack because I'm running completely out of gas, LOL.

PS riding bellow 50mph renders a decrease of 1mpg. Riding bellow 40mph renders a decrease of 2mpg. Riding above 60mph doesn't affect the mileage until you exceed 95mph, in which case it's starting to struggle to keep the speed up (I would assume the mileage is getting worse; I don't ride that fast long enough to know for sure). If the machine can't keep it's temperature down, decrease another 1mpg added to the decreases mentioned above. At least this is how the '05 Fusion 900 is treating my wallet. The worst my Fusion 900 has seen (using my figures above) is 9.59 mpg, which can only get me 103 miles to a full tank vs 135 miles to a full tank with ideal conditions.

Update: I just travelled 110 miles on the one tank, and I'm not on reserve yet. I would guess that I have just under 1/4 of a tank left (I figure I'm close to 1/8th of a tank, or at least I will be if I just ride it around town a little bit longer).[/b]

Wow, I'd love to get 100 miles to a tank, and I'd kill to get 120.

 

[Boogie_ballbuster]

i would love just to get 80 miles a tank, my 98 indy trial is lucky to get 65 a tank.

 

[xltier]

i would love just to get 80 miles a tank, my 98 indy trial is lucky to get 65 a tank.[/b]

something is definatly wrong.im gettinf 12 with a 800 and im no putt putt.my boys xc 600 gets the same and he is on the bar constantly.

 

[Pepsi_fuzz]

something is definatly wrong.im gettinf 12 with a 800 and im no putt putt.my boys xc 600 gets the same and he is on the bar constantly.[/b]

Basically what I was getting at: the faster you go the better the mileage. If you're playing in drifts and fluff and what-not, you'll burn gas crazy. If you can get your speed up, it's not working as hard to spin the track. Also, if you're tracks smaller, you get better mileage. If you're driving an RMK or long-track sled, expect worse mileage.

I'm sure the 98 indy trail has a smaller gas tank, which is why it's only getting 65 to a tank. But then again, I'm not sure on that

 

[Boogie_ballbuster]

I'm sure the 98 indy trail has a smaller gas tank, which is why it's only getting 65 to a tank. But then again, I'm not sure on that
[/quote]

The sled has a 10.5 u.s gallon tank on it. Cost me 46 cdn to fill it.

 

[Pepsi_fuzz]

I'm sure the 98 indy trail has a smaller gas tank, which is why it's only getting 65 to a tank. But then again, I'm not sure on that
The sled has a 10.5 u.s gallon tank on it. Cost me 46 cdn to fill it.[/b]

Eeek. Mines a 10.8 US Gallon tank. I get upwards of 135miles to a tank. Ya need to buy a Fusion b'y :wink:

 

[Boogie_ballbuster]

Eeek. Mines a 10.8 US Gallon tank. I get upwards of 135miles to a tank. Ya need to buy a Fusion b'y :wink:[/b]

I am going to sell it next year i think and save up for somthing newer and can handle my habit of driving.