04 Viper-s Will not rev pas about 7200 anyone have any ideas?

doc04viper-s

doc04viper-s

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Dec 6, 2004
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56
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Dakota, IL
I have a brand new 04 viper-s, I went up north over the weekend and the damn sled just would not get going. The dcs would blink just above 7000 rpm. It seemed to run good up to that mark then it would just fall on its face.
I did manage to get 130 miles on it and ran out that first tank of gas with oil added. I was hoping that leaning the gas in the tank would have helped but it did not. I was just wondering if someone had any idea's/ I was hoping not to wait the two weeks before the dealer has a chance to take a look at it. #$%&*
 
Check your lines running from the carbs to your airbox might be the simple fix. make sure everything is hooked up tight and the plastic tee is not cracked or something. Could be other things but it might be as simple as this goodluck.
 
clean your carburators.if the dcs light keeps flashing it is to lean,probably pluged main jets.good thing for that dcs or you would of probably burned it up!
 
I am going out to check out the fuel lines right now. It should not have leaned out with oil in the tank as well as the injection should it?
 
No broken fittings and every thing seems to be tight. Remember the sled started doing this on the first mile.
 
I'm assuming by the way you're talking that this is a new sled? How many times did you "have" to fire it up for your buddies? Sounds like it could be as simple as you fouled that wet looking plug. If that's not the case, then I'd clean the carbs... it's amazing what you'll find sometimes.

As for the oil in the tank... Since the oil doesn't burn like gas, you are effectively leaning it out by having oil in the tank.
 
I'll go with the fouled plug. Those things seem to need alot of choke to get running and the pto is the first to go. Also, I've had to clean the carbs on numerous new sleds.
 
I would also go with the plug. I have a 2002 Viper and it fouled a plug per cylinder in the first 100km. It is stock jetted and still fouls the pto plug at least once a year. When it does it woun't rev anywhere near 8000rpm.



:rockon:
 
I had the same thing happen to me this year, pto side fouled two plugs, never done this before, i put a br9ecs in the pto side and it fixed the problem. also noticed that plug burns consistant with the other two and runs cooler.
 
Is the PTO cylinder the higher Cr one? What does PTO stand for?

I do know that oil in the gas reduces the octane rating , I would try a nice shot of premuim and see if it still does the same thing.
 
Ok, I checked the plugs every time I stopped always the same result, pto a little darker than the other two. I also changed the plug on the pto side atleats five times to see if it would clear up. ok here is maybe a stupid question. Define leaning, is less oil leaning it? is restricted fuel flow (more air less fuel) leaning it out? lets say it is on the lean side shouldn't the plug be nearly white?
What exacly does the DCS do? I was under the impression that it advanced or retarded the timing wich in turn would limit power (via combustion). What tells it to take over? is it vibration? heat? ????
You guys seem to know quite a bit thanks in advance.
 
I'm with trucknut. If that sled was set-up and fueled last fall the carbs could very well have partially plugged main jets. My brothers Ski Doo went down it's first ride out of storage for that reason. The DCS saved your bacon by sensing the detonation (vibration picked-up by knock sensor)and retarding the timing. Check those carbs and when in doubt about how long it may sit between uses always use a good stabilizer to maintain octane and eliminate fuel gumming and varnish in carbs. The plugs can still show evidence of running rich if you're not running on the main jet cicuit especially on the PTO side with it's lower C.R.. A partially plugged main will only really cause a problem at 3/4 throttle or more.
 
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I think your on to something. I never gave it a thought but I bought the sled brand new several weeks ago (0 miles). I know thay had not run it because the serviced it while I was standing there. But that does mean it could have been put together last year? Not sure how there could be gas in it but I am going out to pull it apart quick and have a peek. And that is exactly when it happens 3/4 throttle.
Anyone know where I can find a shop manual (Not just the owner manual) on the net?
 
my brother in law said they allways pull the carbs apart when they would put new sleds together,said alot of times there would be some kind of film in them.maybe your carbs were not opened up and checked-Harvey
 
they ship the sleds with alittle gas in them. when i bought my sxr last year the dealer said this and wouldnt let me take sled till he removed and cleaned the carbs. he also flushed out the gas tank to get rid of the old gas. salesman told me there was crud and varnish in carbs when they cleaned them. so bring it back and get the carbs cleaned. after all it is a new sled isnt it? warrenty!
 
Yes, Yes and Yes. Here is the delema. I looked everywhere for this sled I wanted it bad. I found one at a dealer in by Chicago. (about 3 hours from home) I got to tell you this place was the worst. No one had a clue about snowmobiles, they sold mostly bikes. Anyways Trust me I didn't buy it there for there service. It was just the only place I could find one. Get this, instead of going over the sled and options with me, the guy asked me if I would just sign off on it because I probably new more about it then him. Anyways I have to wwait 2 weeks before my local dealer can get to it, and if snows and all he finds is some carb cleaning or something like that i am going to feel pissed I didn't get to ride it, and a bit stupid that I didn't come accrossed it myself. Thanks again guys.
 
where did you buy it. The carbs may have a brown substance in them. Thats the oil they break them in on at the factory. The gas tanks never have gas in them. A sled cannot be shipped with flamable fluids in them, but, if you look at a new sled before it is prepped there is about an inch in the bottom of the oil tank. Thats whats in the carbs if it sat for a while. Carb cleaner will not remove it. Use the product that any manufacturer sells to spray in the motor and removes carbon. I don't know what Yamaha calls it but OMC its called engine cleaner, Mercury calls it Power tune. Spray that on gummed carbs and the stuff comes right off.
 
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