Chute Climbs?

Lund

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Like always you can count on Yamaha to get it done, good job Josh.
PM me when your back and planning to head into Turtle, i'll try to hook up with you for a little slaying.
 

06 Dragon

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Thanks. Yes it sure was, I may need chuck to do some work to mine. The engine is stock so I only run 10lbs max on 50/50.
 

06 Dragon

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No headshim. Stock engine. You think I can more? I have no A/F gauge, only boost. 2014 viper with Boost-It Turbo kit.
 
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Lund

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No headshim. Stock engine. You think I can more? I have no A/F gauge, only boost. 2014 viper with Boost-It Turbo kit.

Yep, no head shim your good to 12lbs on 91oct. I actually ran my Nytro at 16lbs with only 91oct never an issue. But i don't advise that.
If your going to stay at 10lbs go with straight 91oct only. The 50/50 is robbing you in power otherwise.
But your safe to push up to 12lbs if you want on 91.
 

Woodsie1984

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Man I need a 174...Cr 163 won’t hold the front down like that...baker skid on that viper?
 

174mcx

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Yes a Baker, still took quite a bit of fiddling with mounting holes and suspension setup to keep the front down in the viper chassis, they seem to lift skis easier.

I ran 12lbs and 50/50 on a stock motor in this viper, for about 3hrs! then I needed a head gasket. Your viper will have a 2860 and a water to air which makes comparing boost levels with the mcx 16T not really comparable. I have 2 close friends that run vipers with boost it kits and we have run close to every different combination between the 3 of us. IMO if you want more power, do head studs and run straight race and go to 13-14lbs, or put in a headshim and run 15 on pump.
 

Clode

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My Nytro with a 2860, water to air, steel headshim I ran 15lbs on 91.
 

174mcx

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Turn it up then I guess is the answer! and post some videos of chute climbs!


Oh I missed the headshim part, get a headshim and turn it up!
 

Lund

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I also ran the 2860 Garrett for 8 seasons, no head shims on 91oct.
When i first put it together i ran 50/50 at 14lbs and slowly reduced the race fuel till i ran only 91. "You should always make sure you have an O2 sensor plumbed in, they are cheap enough and you can watch what is happening".
The Vipers had two different version of the 1049, the newer version was crap for boost, i don't remember the year but i think it was the 15's and up??? maybe some 14's.
I rebuilt Chris Brown's Nytro after he burned it down while boosted at 18lbs on 91 only, it actually took a lot to do it, long WOT in Pemberton.
I have a friend that ran his Viper on 50/50 with 10lbs boost, i finally convinced him to try 91 only and he was amazed at the power increase and throttle response.
 
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Lund

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I have to mention and it has been left out of the conversation, elevation.
If your going to ride in the lower zones, head shim and mix yes. I tend to forget at times because i strictly ride at elevation alway's.
Riding style and location will dictate a lot and at time i forget that. Every boosted 4stroke is slightly different and why a gauge with O2 readings imo is a must in not just monitoring but in getting the most out of your engine without hurting it.
So ya i ran 91 in my Nytro at 14lbs all season for many years but i shouldn't advise it unless you are able to monitor your own. Better be safe then sorry, 174mcx recommendation is sound.

I also forgot to mention on my Nytro i had the ability to adjust and change the fuel mapping, with a Boondocker controller.
 
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06 Dragon

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Thank you. We may have to start a new thread viper mountain sleds and mods and have the moderators move the non chute climbing chatter to it.
Sorry for getting off topic.
 

Dragonalain

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Lol... Trash panda and Max power.... those are classics. look forward to some more vids.

Trash panda we build from left over parts. It works very well which is kinda odd
2011 pro rmk 155
2014 bottom end 2011 cyl
1- mtntk piston
1- random piston which now has oil holes to match the other pistons weight
163 ezryde skid from a cat
174 camo x 2.5
2011/12 shocks
2013+ 36 inch a arms
Boost it ho turbo kit
Redlines x2 fuel box.

The ezryde skid was interesting. for a proper length track I think the mounting point was 5 inches back. with the longer track the front mount Is closer to 10 inches back. The track angle is almost zero.

We built it for under 4000 that included buying the blown boost it pro.

Trash panda would do 65 mph up anything. Buddy did some clutching and is closer to 75 now. Should be a interesting weekend.


Max power well the last 2 years I’ve been running him at 12-15 pounds boost.

In this photo we had proper a arms for the shock length but it’s was to nose heavy. Tossed the a arms that needed shorter shocks with the longer shocks on and it’s just perfect. We also build some different drop brackets once we figured out the sled Actually worked.

1fa5f1e78c8c8a7a1fbff0d262fd5237.jpg
 

fredw

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Ran into a young good rider from sask last weekend (Darby).. fog was to thick to climb Swanson and the ninty that day, but showed me some videos of them the day before where he went up it in a stock summit tdoo 850.. even had the stock skid

Definitely rode it with the skis in the air, and not much fresh but did the pulls.. would of never thought it could of done it.. pretty cool
 
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