Hi guys only my 2nd post so bear with me.
I just picked up this sled for 1700 that had 3k on it all stock. Took it out 2 weeks ago and center crank bearing went. Plugs look good cylinders are all fine. So what caused this? I'm not sure what to look for. I used yamalube and filled tank with 91octane. I have pictures on my phone that i can post if that will help.
I just picked up this sled for 1700 that had 3k on it all stock. Took it out 2 weeks ago and center crank bearing went. Plugs look good cylinders are all fine. So what caused this? I'm not sure what to look for. I used yamalube and filled tank with 91octane. I have pictures on my phone that i can post if that will help.
Devilin AblueDress!
New member
I run 93 or better in all my yamahas. 91 might cause problems in the top end (lean burn down) Bottom end going....My best guess would be poor summer storage lead to corosion/rusty bearings or lack of oil to cases. Oil pump should have line going to cases as well as fuel pump.
There has been quite a few posts on here about the vipers and this problem. First, it could very well be a dirty carb on that cylinder which would give it less fuel/oil to that cylinder yet run great on the others. Lack of fuel to cool and oil to lube = seized lower end rod bearing!
Also, when yamaha released that viper, they stated that it had a new oil pump that used 25% less oil than say the srx. This seems difficult to understand how reliability could be the same with such a similar engine so a LOT of guys have bumped the oil pump setting up to srx levels. I would totally recommend looking into that after the crank is repaired.
Good luck!
Also, when yamaha released that viper, they stated that it had a new oil pump that used 25% less oil than say the srx. This seems difficult to understand how reliability could be the same with such a similar engine so a LOT of guys have bumped the oil pump setting up to srx levels. I would totally recommend looking into that after the crank is repaired.
Good luck!
Devilin AblueDress!
New member
Pics almost always help. Something you dont even notice or dont think is worth mentioning may stand up and holler look at me to the rest of us.
Devilin AblueDress!
New member
I would be adding octane booster with 91 as well as check into opticool head gasket and fatten up carbs settings.
cappy65 said:
as others have touched on , if this happened in the cruise section of throttle at about 40-50mph steady, its the needles that bit you in the butt.
With todays crappy gasoline, you NEED to raise the needles on a viper or it will do it again. Plenty of post here about raising the needles on a viper.
Run as much octane as possible, if all you can get is 91, then buy some octane boost and add it at every fill up, its alot cheaper then pistons.
what kind of octane booster should be used and how much per fill up..i only have access to 91 aswell so how much is needed to bring it up to correct octance level (what is the best octane level for the viper)..does any kind of octane booster work like stp?
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Devilin AblueDress!
New member
viper700t said:
I would avoid anything STP in your sled, fine for 4 stroke not so much for 2 stroke. I have used klotz,lucas and lately amsoil. 93 pretty readily available here. Have it in the back in case I have to fill up with less than 93 or if I plan on sled sitting for a couple weeks as a stabilizer. As far as how much.....Read the bottle of what ever you purchase.
With todays crappy gasoline, you NEED to raise the needles on a viper or it will do it again. Plenty of post here about raising the needles on a viper.
So your saying i need to turn my mid range out a quarter turn and everything else leave alone? Will use the booster also.
So your saying i need to turn my mid range out a quarter turn and everything else leave alone? Will use the booster also.
crazykid
New member
Nope! you need to raise the needle, A little more involved than just turning a screw. Your talkin fuel screw and its more for the idle circuit i believe.
crazykid said:
Okay I had no problems tearing this engine down but I'm definitely scared to mess with the carbs
Is there a link with pic that would take me through this step by step?
staggs65
Moderator
devinzz1
Active member
Why is there so much talk about having to run high oct. Ive run 87oct. only in my sled for 15years with nearly 20000km on original engine???
staggs65
Moderator
so you've been riding and buying the fuel for your sled since you were 7 years old.devinzz1 said:
Devilin AblueDress!
New member
Not following the "turn midrange out a 1/4 turn......) raise needle positon under black top hat on very top of carbs. How much depends on where your at, temp/elevation and other mods on sled. Theres quite a few threads covering it in detail.
Devilin AblueDress!
New member
devinzz1 said:
Higher octane has become more of an issue with the newer (00 and up especially) due to ethanol and leaner running engines from the factory. IMO 87 of 10 years ago better than todays 93!
devinzz1
Active member
staggs65 said:
Actually that would be since i was 1. My dad bought it off the showroom floor back in 97. it was only ever used here. he handed the sled down to me a while back because he bought a new 4 stroke venture. Ive been racking up the miles since, ridding every day i could.
devinzz1
Active member
staggs65 said:
not sure why it says 1990 on my page? but it is on feb. 17
devinzz1 said:
I believe your red-head was designed to run on 87 where as Viper and SRX have a 91 minimum.