Super Sled said:In the Vipers the lean spot was middle rpm's while you were just cruising down the trail. Not delivering enough oil i believe or fuel. That's why you really are smarter to blurp the throttle from time to time while cruising down the trail on the Viper -- so oyu don't stick in that lean spot for too long.
Super Sled said:It really help to have better cooling on these Vipers also. Either a replacement head with water rail or opticool head gasket. Anything that will allow the engine to stay cooler. The stock heads and head gasket do a poor job of keeping these engines cool. Then when you get into those situations cruising down the trail, everything adds up and catastrophe can strike. I added better cooling and a engine coolant temp guage with the hopes I could catch this if it ever started happening. I also have richened up my oil cable a bit for more oil when I blurp the throttle.![]()
I believe it's the oem head-gasket itself that causes the poor cooling.Sxr700Bandit said:Is there a way to modify the stock head by opening the water passages in the head? Or is the design so poor that it is just wiser to use alternate heads(SRX- A/M, etc).
musselman said:I believe it's the oem head-gasket itself that causes the poor cooling.
Sxr700Bandit said:So then technically the opticool gasket forces the water to pick up more heat along with re-routing the water instead of letting it free flow.
sleeper_dave said:More cooling is a band aid way to fix a lean spot.
My waverunner (yamaha GP1200R) has a similar issue. It's a 2 stroke 3 cylinder with a catalytic converter and carburetors. Bad idea from the start, right there. Jetted lean from the factory to keep the cat alive. But even with no cat, jetted fatter, it burned down a second motor on me from cruising in the midrange for too long. Burnt two motors by running ~20 miles at ~3/4 throttle. I guess there's just a weak signal there that you can't really tune out with the carbs. So I just run harder / faster. Not a cooling issue on the PWC because the lake water keeps it plenty cool. Ski runs Mikuni SBN 44's, 3 of them.
super1c said:Agreed to a point. The viper was built with a poor head design to start with, the opticool helps that but is not a fix all. Also the needles need to be moved up. And most important is MRVIPER said to move the needles so thats all i need to hear. Also run closer to 50:1 with oil.
SXRider7Hundo said:Whoa whoa, Chris, bro, what is 50:1 with oil? You mean adjusting the pump differently? Premixing on top of that? I know the jets and opticool for extra measure but what's with that? Ive never heard about this... I am only running my vipers oil pumps at stock specs but a touch to rich.
Enlighten us brother...![]()
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