Another year another Nytro Issue

[sheetwright]

Well had another motor issue with the Nytro. As you may know the first year I had the sled built for boost the original builder didn't assemble something correctly or wasn't using the correct gas and shot the rod right through her. So he replaced it all, and I sent it off to a reputable builder to finish her up and to dial the sled in. The sled was built with the right components (low compression pistons, carillo rods, head studs, larger injectors, larger fuel system, lobe and cam timing and meth injection) I even used Torco the entire time with the meth as a backup on the first trip. I was running 12.5lbs on a stage two MPI. What happened is I rode for a while through the twist and turn by the Marquette ski hill getting used to the new stance, suspension and power. Then the guys said why don't you drop it off at the hotel and grab your Apex so we can take a long run and not worry about gas. (I only had the standard tank on the Nytro) So as I got near the hotel I cracked the throttle when I saw a larger bump to get air. While in the air I gave the sled a blip on the throttle for sound. Well I landed and I heard a quick zing and then a click/snap. The engine was still running though without any noises, but wouldn't engage. In the dark at first I was praying it was a belt. So I walked the block back to the hotel and towed the Nytro with the Apex. When we got to the hotel we realized that there was antifreeze coming right out of the silencer. We assumed a head gasket. When we got back to my shop we took the gas tank off and started to see that the center piston came up and destroyed the head off of the center spark plug. I also found sections of a ring or sleeve in the exhaust. The outer two plugs were black but not touched though. Which usually means a fuel issue, and center one clean as new. I was running high 11's to 12.5 on the A/F gauge the whole time. I knew the meth was flowing cause I installed a monitor gauge and kit on the three nozzles. What I am thinking I did but not sure till I pull the whole darn thing was drop a valve on the center. By having the boost up in the air then landing it could of pushed the rev limiter and added extra load which dropped a valve. Didn't realize that could happen. If I am very very lucky I could replace the center guts and the head. The question though is it worth it. Yes I have more money then a swiss bank account in this thing that I will never get back. If it was you would you part it out and start with a new milder project, or get this up and running with some miles on it and then try to sell it? I'm thinking parting it out or trying to sell it to someone as a project whole. Just because boosted sleds are very hard to sell, especially in a bad economy with high gas prices. I'm thinking with the bulk of the new parts having only about 300 miles on them and the few stock parts having under 2k on them that I could do pretty good on parts, but still take a complete beating on the overall project. If it was yours what would you do? Any ideas if I thinking the right diagnosis, and in the right direction here? Boost is a true lesson if you want to go over 7-8lbs on flat land trails I am telling you

 

[shadow44]

Deciding on what to do with it depends on how much you love the sled. If you can afford rebuild the motor, then go for it...if you decide to part it out...could I have first dibs on the hood It really is a wicked looking sled...maybe consider rebulding it but with a safer setup...maybe lower boost.

 

[YamaMTX]

Looks like a pretty sweet sled with a lot done to it. Why not fix her and just tame her down on the boost?

 

[sheetwright]

Ya that is my issue. Probably around 25-30k wrapped up in her. With nothing to show but a sweet looking ride

 

[SSX600]

Put a stock engine in it and sell it and then sell the boosted parts and pieces. Sweet looking sled.

 

[sheetwright]

I wish it was that simple. The first builder has most of the stock other parts. Which would also have to be purchased to go stock. The whole fuel system, computer system would all have to be changed back. Along with the clutch that is now a four post. Almost nothing is stock and almost all the original parts are gone. So if I changed the motor I need a lot more.

 

[kinger]

Man if you can't catch a little air without worrying about dropping a valve that sled wont be in my stable no matter how good it looks. I jump my SC apex all the time!

My first thought was nypex get a used apex motor and run 10-11 psi shimmed head like mine. Although its experimenting and I guarentee you would find a wire routed wrong or something when you are in the middle of a trip or something, and the odds of the SC working on it are small since NO one has done that yet, they are all turbos.

If you fix it and lower the boost to 7 psi it will cost you around $3K?

If you fix it and keep 12-13psi it will cost you 3K?

If you part it out with bad motor you can get around $12-14k?

If you fix it and lower boost, then try to sell you can get maybe $10k

Ahh the price of custom sleds!

I would part it out and move on. JMO

 

[Super Sled]

IMHO fix her up and lower the boost for greater reliability.

 

[tjc]

I guess there is a bigger question.... with meth, low compression, good afr, and torco why did the motor fail at 12 lbs of boost?

Boosted sleds get jumped everyday.

 

[HYFLYR]

Theres no way that motor should have failed if you were running the afr's, octane, shim, and meth that you say. Something finally let loose after assembly, something wasnt set right or torqued correctly. However, if your rpms were to high there is a possibilty you lost correct oil pressure to the crank bearings, you would have to be over 9k for an extended period of time, not just a jump or two. I think there will be more to the story once you open it up.

 

[sheetwright]

I agree with I will find out more. Because the two black plugs also concern me with one clean blown off one. I had no shim but I had 9:5 pistons, meth and torco. Not to many areas to open her up. Since the trails we re twisty and not the best in snow cover. Temp was good since I had the extra exchanger, w.etter water, and a lower flap. We will see soon

 

[fast n furious]

Well had another motor issue with the Nytro. As you may know the first year I had the sled built for boost the original builder didn't assemble something correctly or wasn't using the correct gas and shot the rod right through her. So he replaced it all, and I sent it off to a reputable builder to finish her up and to dial the sled in. The sled was built with the right components (low compression pistons, carillo rods, head studs, larger injectors, larger fuel system, lobe and cam timing and meth injection) I even used Torco the entire time with the meth as a backup on the first trip. I was running 12.5lbs on a stage two MPI. What happened is I rode for a while through the twist and turn by the Marquette ski hill getting used to the new stance, suspension and power. Then the guys said why don't you drop it off at the hotel and grab your Apex so we can take a long run and not worry about gas. (I only had the standard tank on the Nytro) So as I got near the hotel I cracked the throttle when I saw a larger bump to get air. While in the air I gave the sled a blip on the throttle for sound. Well I landed and I heard a quick zing and then a click/snap. The engine was still running though without any noises, but wouldn't engage. In the dark at first I was praying it was a belt. So I walked the block back to the hotel and towed the Nytro with the Apex. When we got to the hotel we realized that there was antifreeze coming right out of the silencer. We assumed a head gasket. When we got back to my shop we took the gas tank off and started to see that the center piston came up and destroyed the head off of the center spark plug. I also found sections of a ring or sleeve in the exhaust. The outer two plugs were black but not touched though. Which usually means a fuel issue, and center one clean as new. I was running high 11's to 12.5 on the A/F gauge the whole time. I knew the meth was flowing cause I installed a monitor gauge and kit on the three nozzles. What I am thinking I did but not sure till I pull the whole darn thing was drop a valve on the center. By having the boost up in the air then landing it could of pushed the rev limiter and added extra load which dropped a valve. Didn't realize that could happen. If I am very very lucky I could replace the center guts and the head. The question though is it worth it. Yes I have more money then a swiss bank account in this thing that I will never get back. If it was you would you part it out and start with a new milder project, or get this up and running with some miles on it and then try to sell it? I'm thinking parting it out or trying to sell it to someone as a project whole. Just because boosted sleds are very hard to sell, especially in a bad economy with high gas prices. I'm thinking with the bulk of the new parts having only about 300 miles on them and the few stock parts having under 2k on them that I could do pretty good on parts, but still take a complete beating on the overall project. If it was yours what would you do? Any ideas if I thinking the right diagnosis, and in the right direction here? Boost is a true lesson if you want to go over 7-8lbs on flat land trails I am telling you

I can totally relate to your situation, I have posted on here about my issues with my boosted nytro. I for sure will be going back to a low boost set up and just have a fun play sled. I got so frustrated that I went out and bought a left over apex xtx and put on 800 km final run of the year with no issues and had a blast. And have to say the stock apex xtx works great and very happy i bought it. Now I have to find stock nytro engine to put her back together for next year. Good luck to you

 

[sheetwright]

I decided to say screw it, and put all the parts up for sale in the classifieds. I will look for something else with lower boost. Just wish she wasn't so touchy so I could of got more miles out of her. Thanks for the help guys

 

[sheetwright]

Deciding on what to do with it depends on how much you love the sled. If you can afford rebuild the motor, then go for it...if you decide to part it out...could I have first dibs on the hood It really is a wicked looking sled...maybe consider rebulding it but with a safer setup...maybe lower boost.

Shadow, hood and plastics are for sale along with everything else

 

[Sledboy]

Sorry to hear about your engine woes. I can certainly relate to blown engines and sold or parted out sleds that you miss. My wife just does not understand. Where did you get the graphics on the side of your Nytro tunnel? I want to get some for my XTX.