Run out of oil

[chiefsledhead]

Anybody have the hose under the air cleaner fall off and run their 06 Nytro out of oil?
The motor now has a bunch of bad noises. It still runs, but sounds awful. I know I'm not the first one to have this happen, so I am asking anybody that has had it hapen what did you have to do. Do you think it is just the top end or the bottom end also. Is it worth fixing or just part it out and say goodbye? Any comments are appreciated

 

[nate007]

The bottom end would be the first to go if that's what happened.
Are you talking about the hose that connects to the air box, or the return hose to the tank? I assume you have an oil slick all over the engine then?
As far as what's worth fixing, that's the million dollar question. Depends on what you're comfortable with wrenching on, what you feel like spending, etc, etc.. Finding a used motor isn't cheap, but if your motor isn't totally destroyed, and you feel like modding it, now would be a good time to do it?

 

[grizztracks]

I'll take a look at it if you can bring it to me. It probably spun rod bearings and damaged the crank.

 

[chiefsledhead]

Thats what I needed. I wasn't sure if the top end would have gone first or the bottom end. I feel comfortable doing the work, I just don't know if I have the time and the desire to do it. Shouldd I take off the valve cover just to look, or isn't it worth the effort. When I turn the clutch by hand there is no noise or slop going forward, but when I spin the motor backwards, I hear a real grinding noise. I can't tell if it is coming from the top or the bottom.
Still trying to decide what to do. I appreciate your comments.

 

[grizztracks]

I know there is already damage but don't cause more by rotating the engine backwards, especially if you're thinking about repairing it. I'd pull the valve cover and remove the cams to check the cam journals for scoring due to lack of oil. At a minimum your probably looking at a crank, rod/main bearings and a cam chain tensioner if it hasn't been updated.

 

[rlcofmn]

Yup as stated the crank is junk most likely. Don't run the engine for sure if you know it's knocking. As soon as the lets go your block is junk. Most likely you're looking at a Crank and rod then all new bearings.

I am yet to see a damaged head from lack of oil as the rod bearings fail before anything.

In the current condition if you can do it yourself then most likely it's worth rebuilding.

Is it actually a 06 or is that a typo?

 

[chiefsledhead]

It is an 06 and it is a Nytro. It is basically a carburated Vector with FOx Float shocks. Not too many of them around.
Based on everyone's comments that the bottom end goes first, I might tear into it and fix it. Just haven't had the time yet, been out building trail bridges before the snow flies. ( I have another sled to ride so I am not desperate)

 

[Mtnviper]

chiefsledhead,
When you go to tear it down and if it has spun rod bearings, I highly recommend pulling the valves out of the effected cylinders to check them for straightness.
What can happen, is when the rod bearing fails, it allows the piston to travel farther up the bore (due to the excessive bearing clearance). This can cause the piston can contact the valves and bend them slightly.

If this happens and you don't catch it during the re-build, the bent valve can "hang open" after the engine is rebuilt. Once the valve starts to hang open, the piston smacks it causing the head of the valve to break off and its game over for your new motor. :-(
Because the valves are small there may not be witness marks on the top of the piston. I found that the best way to check the valves is to chuck them up in a lathe or drill press. Then slowly rotate the valve and checking the run-out with a dail indicator.

They don't always bend the valves, it just depends on how badly the rod bearings failed. However it's something you'll want to check before re-assembly just to be safe.

Bill

 

[grizztracks]

With the head off fill the intake and the exhaust port with kerosene then check for seepage around the valve seat. If any are bent you'll see a significant amount of leakage. Been doing it this way for years.

 

[chiefsledhead]

I really appreciate all the info. That is what I love about this site. Everyone is here to help everyone.
I will keep checking for comments, and when I do actually get toit, I will let everyone know what I find and what I end up doing. thanks again.
By the way Grizz, I am in Jamestown

 

[grizztracks]

I ride Chautauqua ridge area a lot. I'm originally from Olean and I'm active with the Portville snowmobile club. If you need any help with the engine let me know. Maybe we can catch up some time.