Viper Questions

ExpertXViper

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Aug 19, 2006
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Livonia, MI
K I have 2 questions:

First: I always run premium in my sled no matter what, even though I dont need to. But seems to run alot smoother and gets a lil bit better mpg. So does this mean I can run one step hotter on my spark plugs? Or is this not a good idea?

Second: I've heard that Vipers are jetted pretty rich from the factory. So can I jet down one step or is this not a good idea?


Let me know
 

check you plugs and if you think it need to be rejetted do it. My 04 has not been rejetted from stock - typically I get 14 - 14.5 mpg, and do not foul plugs.
 
I think the non valved motors are rich, the valved ones (viper and srx) seem to be pretty good. nice mileage, gas and oil wise, so why bother. no idea about the plugs
 
i've been running 152.5's in my viper and never had an issue in +50--30 temps for 5500 miles, 0-4500 feet.
 
The heat rating of a spark plug simply indicates how well it transfers heat away from the electrodes in order to keep them as near optimum temp as possible. Do you have any evidence that would suggest this is not happening. If the engine is basically stock, stick with the stock heat rating (9 for NGK).

What you are seeing in better and smoother running along with improved mileage is likely much more a result of gas quality differences than the octane rating. Running premium fuel in an engine designed for a lower octane fuel actually results in less power. However the difference is so miniscule that you would be hard pressed to notice it even with the use of precision meters due, to the inability to rigidly control all the other factors that are involved.

Now if your engine is modded, and the lower octane fuel is actually contributing to pre-ignition or detonation, then it is an entirely different story.

Bottom Line: Premium fuel is only better if the engine is designed for it.

p.s. The approach that is common among knowledgeable snowmobilers is to use whatever fuel is the most heavily used at the filling location in an attempt to avoid getting stale fuel. Thus regular is ok wherever cars commonly fill up as they will keep the supply turned over. Premium may be a better choice where only sleds fill, and most people use it.
 
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Make sure carbs are clean, insure all boots are airtight, and then read plugs and piston wash to answer jetting question.
 
I'm running the NGK ones right now. Runs smoother and lil bit better throttle response. Dont know if there worth 10 bucks a plug but I'm sticking with them.
 
What plugs are you running that cost 10 bucks a plug. I pay like 2 bucks for my plugs for the viper. Maxdlx
 
Running NGK BR9EIX Iridium, same thing I run in my CR250R. But my CR250R is BR8EIX. Makes a huge difference in the powerband on my bike and have yet to foul a plug. In either sled or bike. Plugs run anywhere from 9 to 12 bucks a peice pending the store. Iridium creates alot cleaner and hotter spark than any other plug out right now. And also draws less power to run. I run these in my sled with premium gas all the time and ever since the change, I have yet to clean my powervalves. Last season put on 1000 miles, I checked them at 500 miles and at the end of season. And they were spotless. So the price doesnt really bother me. "You Pay To Play"
 
The denso iridium plugs are over $10 a plug for a sled. i went to their website and im convinced.

Thats what i had to run in my truck, just replaced them at 100,000 miles at $8 a plug
 
ExpertXViper said:
Last season put on 1000 miles, I checked them at 500 miles and at the end of season. And they were spotless. So the price doesnt really bother me. "You Pay To Play"

What oil you running?
 
Between premium gas and the plugs I run. I'll never go back to regular gas and the cheap BR9ES. I dont care what anyone says. I run premium in my truck with a power programmer and gained 2.5mpg not including my other mods. As long as premium stays under $3.20 a gallon here in Michigan. Ill spend the extra money. A cleaner burning engine is a longer lasting engine.
 
Running Yamalube, I buy what the Makers of my machine makes. My CR250 I run Honda 100% Synt. Premix. Thats what they test these machines with thats what I'm goin to use.
 
Are you serious with that post!!!!! None of the Makers actually make there own oil. They go to a outside companys, instead of having to spend millions of dollars to build a whole division for there own oil and have to go through all the testings. Some companys mix different additives and dyes to make it there patened also. But you read the bottle there bud it is Patended by YAMAHA or HONDA. But u ask 90% of the peps on this site and I bet you they say its made buy yamaha. Didnt know I had to be so specific.
 
I know, and to the lowest bidder I would assume as well. I used to run it and had good luck. seem to have better luck and less odor with klotz. the sxr we have with stock settings runs cleaner. thats all I was getting at. I thought you thought the oil was designed specific by yamaha for the sleds. sorry to offend :)
 


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