crappy running viper

yamatyb9

yamatyb9

New member
Joined
Dec 20, 2012
Messages
68
Age
40
Location
belleville, wi
Went on first ride last nite, buddy's viper ran great then after about 15 miles at a stop sign it just died.. Got it to the she'd, new plus in it and still sounded terrible. Coolant cap was partially off and tank almost empty, all plugs were dry and almost white. Spits and sputters when it's running now, have an idea and am assuming the worst but just checking others opinions. Thanks in advance, not a good start to the season!!
 

first step would be a compression test to see if you cooked it.
 
Antifreeze blew out the cap. Seems to be better this morning but still spits and sputters. Were assuming the worst and hoping for a Xmas miracle! Going in to my friend shop today
 
Good luck to you and hope you don't need to rebuild an engine. I had a similar thing happen to me just after changing piston and rings in a motocross bike. A couple rides later the engine seized on me. It turned out the water pump developed a pin hole after I did the top end. Hopefully you guys caught before it got to that point. There's three times the cylinders on your sled.
 
So finally after a month we got the things fixed and going great.. Ended up frying the cylinders, sent and got new ones and me top end in it now! Ran like a top, cold as hell here lately (highs in the negatives) so took it for a quick ride last night. Turned around at end of field and was just dead. Pulled it back and the center piston blew, when the sled stopped the engine was hardly warm at all so thought maybe and hope only and exhaust valve was stick or something but was the piston.. Anyone have similar problems ever and have any info on what to look at also other than what I just mentioned as a precaution??
 
Did you check and clean your carbs? Verify proper jetting? Clean exhaust valves? This is all pre season maintinance and anytime a motor rebuild is in order. Much more goes into an overhaul than just replaceing pistons and cylinders. Good luck Al
 
Well...That sucks! What was the outcome of the orginal coolant problem? Was it just a loose cap?Is there fresh high octane gas in tank (old gas completely drained out), Carbs spotless, including top hat filters under inlet needles (often overlooked) Have the needles been raised? OEM pistons and rings or aftermarket. Air in the coolant system. Did you let it warm up good ( I'm guessing not since you said it was barely warm when it crapped out). Like Al stated, alot more involved than just replacing stuff, gotta find the root cause as to why it burned down in the first place. If you can, take some pictures of the damage and post them. Alot of smart people on here that are willing to help.
 
Yes all preseason maintenance was done from minor to Major things.! I'm one to make sure that is always done right to a T.. Originally I think the air in the lines has play in the original outcome, and after pulling cylinders noticed that the person prior to me must have honed the cylinders once before already, no nickel was on the cylinders at all. And again yes after all Was back and put together we did a complete overhaul and checking and cleanup on everything. When I say it was cold I mean the block never really got warm while riding for 3-4 mins. I didn't just take and hammer on it when cold, I'm not that petty and realize things need to be cleaned again and again. I always let it idle/warm up atleast 5 mins inside before even driving it. Sorry if I come off rude, I'm not trying to be. Just flustered with the run of bad luck this viper has given me, considering I've owned 2 prior and have another in my garage now and this is the cleanest and best cared for one. Ran great on the stand for and got after all put back together before the ride. Confused the hell out of me
 
take a picture of the tops of the pistons and post it. also the spark plugs
 
The sled is about 30 mins away at our shop so I'll have to post pics later today. We've already installed the piston and heads are back on. Was just seeing if anyone ever had this happen also? I'll try finding the old piston and plugs when I go down there later today. Thanks
 
so you just put another piston in it and are gonna run it again?

piston being burned is usually from:

1.) bad gas/low octane
2.) incorrect jetting
3.) dirty carbs
 
Not just any, brand new wiseco in it now with new to end. Just now carbs are being cleaned, gas was drained last night even though it's only a month old and new gas being put in today. My mechanic that is checking jetting in it also. 91 octane has been run through it, would ruin 93 if our local gas stations would carry it.
 
Are all three Weisco? Aftermarket tend to cold seize much worse than OEM. If 91 was all that was available I would run octane booster as well. Raising the needles is a good idea as well as correct jetting. Opticool head gasket?
 
I've thrown octane boost in the sleds when filling up with 91, to be honest I don't know for sure the gasket in it. I'm not doing all the mechanical myself. Just getting the info and tips and letting someone that knows all about this better than I do the work on it. I figure 91 is low so glad to hear someone else tell me to run boost with it also, considering nobody we ride with puts it in
 
The Vipers have more compression. Add to that the advanced timing curve and less than desireable head design can add up to a problem. I have ben running SRX's for years and picked up my first Viper last year. READ A TON OF THREADS! Needles in my opinion are the biggest thing over looked. They need to be in position 3.25 for average rider or 3.5 for putt putt riders. Rear cooler and Opticool gasket help a lot as well.
 
91 is all we have here for years now as well as many other places. A stock Viper or SRX survive just fine on good 91. Some octane boost is good insurance though along with the raised needles, opticool gasket, and rear cooler. My modded Viper requires some custom blending for me but all my stock sleds just get 91
 
Thanks Alot guys, appreciate all the heads up and tips!! This site is great and knowledgeable, thanks again for all the help. Hopefully this time around is better
 
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