viper gas mileage

coyotekid

coyotekid

New member
Joined
Nov 16, 2003
Messages
21
Age
53
Location
Oakland, Maine
I have a 2002 viper with M-10 in the rear, SLP SLT skis up front, TPI valves(3) in the air box, and rear heat exchanger. I love the sled, but I'm only getting 11mpg. My dealler says it's because of the M-10, but everyone I ride with has an M-10, and they're getting the same mpg out of they're twins (which have at least twice the miles on them) as I am with my triple. Any ideas?
 

I've got a CPR piped Viper and I'm getting 11 mpg with it so you should be getting way better than that (at least 15 mpg I would think). I've never ridden mine stock but I've always heard how good the mileage was on a stock Viper so I'd do some digging. My buddy has an M-10 on his SRX and it didn't affect his mileage at all. What kind of conditions do you ride in, what is your jetting, clutching, etc. How many miles on the sled? How does it perform compared to other sleds (preferrably Vipers). Has it always got poor mileage or did it degrade over time?
 
I ride exclusively on packed trails. The sled has 3000 miles on it and performs similiarly to a Ski-Doo mx-z 700 with 8000 miles and a Polaris xc 700 with 10,000 miles (both with M-10's). The clutches and jetting are stock, and I've never riden it with the stock suspension. It's always gotten about 11 mpg and I've never been able to really put away any other 700s. At best I run even with Ski-Dos and Polaris', and I've never run with another Viper. Previously, I ran a 1997 SX 700 with the same skis and rear suspension, and my Viper is very similar in performance and gas mileage, just having a little more snap.
 
You need to provide more details, like what your engagement rpm is, your shift out rpm, abnormal belt wear, plug color, piston wash...we could go on.

Did you brake the motor in on Yamalube, or a full synthetic?
Have you checked your power valves lately, and adjusted them?
 
I can't tell you about the engagement or shift rpm's, or the pistons, but I can say that the clutch set-up is stock, the belt is new, the power valves have been cleaned but not adjusted. I've gotten poor gas mileage since the first time I rode the sled, which was last year. I've never ran any other oil other then amsoil synthetic, which my dealer thought might be better for the power valves then Yamalube. I bought the sled as a leftover last year and put 3000 miles on it. My dealer insists that the poor gas mileage is due to the M-10, but I think he's crazy. I'm basically looking for any posibilities as to why I'm getting such poor mpg, as that is one of the Vipers strong points.
 
coyotekid - Do you notice a change in mileage or performance when it's cold (say 0 degrees or colder) compared to warm weather? You said you ride all packed trails so I'd say your mileage should be 15 mpg minimum and probably better than that. What vmaxjohn was getting at with his clutch questions was to fid out if you have a wear/cleanliness/calibration issue w/ your clutches. I agree with him that you need to give more detail. Have you ever blown a belt with the sled? If the sled's accessible now, go out and start it and tell us at what rpm the clutch engages at. Also, if you can recall from riding last year, what are your rpms at full throttle (say on a lake). When you punch it, do your rpms go right to 8500 or do they slowly climb or overshoot? How is your hyfax wear on the M-10? The reed suggestion is also a good one but I'd think you would have noticed a degradation in performance & mileage from new and you said it's always been that way. I would say, however, that your dealer's full of it - it's definitely not the suspension.
 
CLUTCHING. Believe it or not the clutch calibration can make or break your gas milage. Example: my cousins 99 srx pulled 13 to 14 initially. After installing a Bender kit the G milage was about 17 to 18 with NO other changes. Keep in mind several other factors such as track tension/trail conditions, altitude and riding habits can drastically change the fuel consumption. Believe it or not, my 93 vmax4 was actually better on gas at higher speeds. between 50 and 100 in canada I'd pull about 11.5. Ride it slow I'd be looking at about 10. Just the opposite, My 95 vmax 500 could pull about 14 cruising and sucked it down at about 9 pushing it. I'm installing bender kits into my srx and sxr , simply to improve the gas. There may be other kits that provide better performance and gas milage, my choice is to go with this kit because I know it works. I'm just touring, not racing. The numbers aren't B.S . This same srx went 196 between fuel stops and pulled into the gas station under its own power.

Rock on!
snow is on the way!
ps: If you passed last year on I93 or I91 in nh or vermont by a 97 sho taurus going 80 + towing a two place inline, that was me! Picked up an explorer this year. Taurus was great until it snowed, then I was screwed.
Would get 15plus mpg towing.
:shock:
 
Have same sled with Expert X, but even when stock it didn't do better than 11-12 mpg, I think it has alot to do with riding style. I'm either on the flipper or off, there is not much inbetween with me. My srx was the same, my girlfriends sx700 with her on it gets about 1mpg better. I don't think its the skid as the expert is the easiest turning of all. All my sleds are stock.
 
I've been away for a couple of weeks, but I'm back now and would like to get back to this gas mileage issue. The clutch engagement is 3500 rpms, but I can't remember what the sled tops out at, and unfortunately I'll probably have to wait a few more weeks to find out. I've never blown a belt, have new hy-fax, keep a close eye on proper track tension, and never noticed any diference between warm or cold days. As far as riding style, I don't think that would be the problem based on previous sleds and compared to my buddies sleds. As I mentioned earlier, I'm getting about the same mpg as my buddies twin 700s, which have double and even triple the miles on them, and we all ride pretty much the same. Aggressive trail, mostly big fast trails in northern Maine and Quebec.

Thanks for all the input, and I think this is a great site.
 
1. Clean Carbs and Check Reed Valves
2. Verify Jet sizes, and Needle Position
3. Check Engine Mounts
4. Adjust Power Valves
5. Align Clutches
6. Check Jetting (Piston Wash and Plug Color)
7. Check Engagement and Shift RPM
8. Make Clutch Changes as Necessary

In that order
 
Fuel mileage

Track tension-My Polaris M-10's say 1/2" to 3/4" of free hanging slack at 16" ahead of rear idler center. I tryed near 1" slack& gas mileage improved without ratcheting. Might be worth a try.
 
Just to add to what Ding said, check the float height on the carbs while they are off.

The best out of my stock Viper is around 17 mpg, that was on a long trail ride at very moderate speeds. The mpg drops off when I run hard but it is still quite good.
 
dude if the m-10 hurts fuel milage I'm definately in trouble. I only got 95 - 100 miles to a tank before I put the M-10 in!!
 
My Viper was really poor on fuel mileage also. Never did find a reason. Gave up and just added pipes so I don't feel so bad about it. Mine got ~10MPG in stock trim. With pipes I am ~9MPG. My dealer insisted it was riding style. I am an old disabled guy and don't ride my sled that hard. I did however find significant blow by when I opened my motor to do the head swap.

There is another thread on here about it too. Someone that has expended some significant effort in trying to track down the cause.
 
I get 18 MPG!

My 03 viper gets 18 MPG on average. I use to get around 15, but ever since I added the zx2 skid and changed the drive shaft bearings the mileage went up. Does your sled really coast when you let off the gas? Mine coasts really well on groomed trails and I find myself using the break alot. Another test you can do is put it on a hill and see how easy it well roll backwards (or if you load it on a trailer, roll it off back-wards by pulling on the back bumper. The sled should roll real easy, if it doesn't you need new drive shaft bearings.
 
02 viper mileage

Got 2 o2 Viper er"s with M-10'S, wife drives one ,me the other
all ways get 13 to 15 MPG. 1" plus free hanging slack in track.
woody dueleys, Blue Marble oil
put one set of slides on at about 3000 mi. mine [HYperfax}
thought I was going to have to put slides on the wife's sled this
year ,but we ran out of winter. 2300 mi on her M-10 slides

later dr4pat :winterrul
 
Take a look back in the posts... all the vipers that are getting 15 + mpg...are in CANADA...

Are we all using US gallons or are they using imprial gallons ?
 
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