Viper not running well

YamahaXtreme

YamahaXtreme

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Went out for a short late night cruise last nigth the machine was running great till about 50 miles into the the trip. The engine started running a little rough still seemed to have quite abit of power. At first you could barely notice the difference it was kind of off and on. Well I came to an intersection and I noticed it was idling pretty damn low around 900 rpms and when I went to put it in reverse it shut down on me. I figured it was just a fouled plug, pulled them wiped them clean(they looked fine) It started up fine with no problem I continued on just trying to get home or closer to a road. Anyways the performance kept decreasing as i went along alot of bogging and sounded like it went down to 2 cylinders then to 1.. I should also mention I heard alot of rattling couldnt really pin point where it was coming from. Well to make a long story short I had to tow it home.
Sled is 03 Viper completely stock with 6000 miles just put on it yesterday :o|
Need some suggestions from you tech heads, thanks guys
 

ouch. pull the plugs and do a compression test 1st. if you see a white plug though don't bother as that tells you motor needs to be torn down.
 
Yeah, doesn't sound good. Did you clean the carbs before start of season? My guess is plugged jet(s) and went lean. Plugs should tell the story, betting you'll find a white one or silver because of flakes all over it.
 
What kind of scenarios would cause a burndown besides running to lean? Pulled the carbs this morning and they looked great, clean as a whistle. I forgot to mention I pulled the plugs again and noticed the electrodes were touching eachother. Something must of blown inside and smashed agaist the plug. #$%&*
 
she's #$%&* ..start pullen her down.

dirty carbs, bad gas, wrong plugs, detonation may have got ya, post up
some pic's and we can help ya..
 
What do you guys keep meaning by white plug? and yes I cleaned the carbs be4 the start of the season and checked them today there fine.
Rich no It was my 2nd weekend up north I put on about 350 miles so far this year. Wish it could of happened within the last couple weeks of riding.
This season I've been running her on 87 for fuel due to money issues. Hope I didnt F*ck myself by trying to save a dime or two!!!:whine: :o|
 
This kinda of story scares the crap out of me. I have not cleaned my carbs this year on my Viper but runs fine for now. Did yours run ok and then just start running like a bag of poo? Did you clean your carbs this season? I am just trying to learn from others so get back to me only when you have sorted out your problems and have the time. Thanks!
 
I run 87 fuel with a piped viper. I go wide open for miles no problem. I stripped the pipes to bare metel. Nice and blue now. Anyway i doubt 87 fuel caused your problem. Could be a crank seal gone bad.
 
If guy's aren't going to clean there carbs,should at least keep an eye on plug color/wash!!!!!

and run good gas,at least mid grade, seeing alot of burn downs this year.
 
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I bet it was the fuel!

If your engine is use to running good fuel and you switch it, I bet it was the fuel. I always run 91 stuff, that way if I run into a station that only has regular I will end up with midgrade in the tank. These Yamaha tripples need a min of 89 octane fuel. I have 7500 miles and the engine is still perfect. May seem a bit expensive but you only save $4 on a tank by using the cheap fuel. Why risk it
 
I would NEVER run my piped sxr with high compresion on 87 octane. I use 91 or higher only. Ay 87 if you get questionable fuel POW there goes your motor.
 
wantsnow said:
This kinda of story scares the crap out of me. I have not cleaned my carbs this year on my Viper but runs fine for now. Did yours run ok and then just start running like a bag of poo? Did you clean your carbs this season? I am just trying to learn from others so get back to me only when you have sorted out your problems and have the time. Thanks!
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My sled ran like new for 300 or so miles prior to this incident. I did clean the carbs and vavles before I took here out. I consider that a must do. You never know what its going to look like after a year of sitting. The way I look at it the one year you skip cleaning them is the year there gonna raise holy hell on you. If its been running fine for alot of miles Id say you'll probably be able to wing it but it never hurts to pull them apart and check for reinsurance. Doesnt take long to Clean the carbs I spend like 60 mins on mine.
 
Is there an explanation for needing high octane fuel when the compression on these machines is not really that high? Or did I read wrong about the 6.5:1 compression? Thanks.
 
YamahaXtreme said:
Any tips or prehaps some directions showing how to tare apart the engine? Do I need any speciality tools to do this project? Thanks guys your help is more then appreciated
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Pretty strait forward, drain coolant pull carbs/air box, pipe,clutch,hoses, then head jugs,etc,etc...

pull the motor right out easier plus need to split case do seals,check crank
etc....

clutch puller ,fly wheel puller will be needed.
 
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if it closed the electrodes (gap) on 2 plugs it is the crank bearings that let go. might have a plugged oil passage.
 
I think it's a pretty safe bet that regular fuel hasn't screwed any stock Viper motor.Mine has approx 12k miles and the only time it ever got anything but regular is when there was nothing else.Now bad fuel(water in it) is another thing.A little shot of gas line anti-freeze in the tank if the fuel is questionable will save you lots of headaches.And leave the carb warmers on.JMHO.
Was it fogged when it was stored?
 
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