Ran 02 sx viper 700 without oil......

[bmaahs]

Not sure how long - the wife went sledding without me - she wasn't sure where to add oil - so she didn't......
When I got there the oil tank was empty #@$%

The motor starts ok - but now the exhaust is loud and the engine misfires a little at lower rpm's.

Compression was 95 105 105

Wondering if anyone had a similar experience - planning on ordering a rebuild kit (piston rings, pins) looking for some advice on what to watch out for.

 

[zr7cat]

That's it, the wife is grounded!!!!!

 

[YAMMIEGOD3:16]

glad you got there before kaboom. 3;16x (yammie tony)

 

[roudyroy1]

i would inspect the crank very closely

 

[Mac]

Welcome to the Forum. No oil..... is never good.

But from the sounds of this story you just don't know how long you were running on empty. Maybe even not at all. Did your wife say the oil light came on? The compression numbers are not so good. Also how many miles are on this engine? The fact that it didn't seize is the good news. I would pull the cylinders and inspect. Maybe you get away just re-ringing the engine with base and head gasket. i would pull it apart inspect and take it from their.
---Mac---

 

[Mac]

Re-thinking this. I would bet one of the rings is stuck. You said - - - The engine sounds different, backfiring, no oil. I would suspect the engine overheated causing the exhaust side of the piston to smear aluminum and jam the top ring or both. Pull the exhaust off and you can confirm looking at the piston thorough exhaust port. If you are lucky maybe the cylinder is still good. Don't keep starting the engine cause it wont magically get better. Sometimes the ring jams on a port and destroys the piston cylinder and crank. Open that motor. Take pics. Report back with findings.

 

[captnviper]

Sounds like it ran dry, by the way you said it runs. You can clean the aluminum out of the cylinder with muriatic acid http://vintagesleds.com/bs/index.php?topic=50790.0 post pics. Hope its just some cleaning and rings.

 

[captnviper]

Another question have you used this compression tester on other motors? The numbers are low but consistent.

 

[bmaahs]

Thanks for the info - answers to your questions:
a. Wife claims the oil light never came on .....
b. The sled has 4900 miles and was running great before the fateful trip.
c. Just bought the compression tester from Napa - it's brand new.

Hopefully I will be able to get it apart this weekend and report back!

 

[mrviper700]

I doubt it was out of oil, you cant see the oil in tank when it gets down to the last 1/4, the light would have come on and then shortly after that the engine would have abruptly stopped. I would instead get a mirror on a stick with a mag light, inspect the exhaust manifold as on vipers they like to crack between where the pipes join, they crack on the bottom and top, but bottom is most common, this is likely why its louder and misfires, but still starts good. Also the compression readings are correct, it is lower compression on the pto cylinder on a viper and your readings while low are likely the guage with a long hose, adding volume which reduces the reading at guage. I bet theres nothing wrong with engine other then a cracked manifold, which is very common, I have welded up 100's of viper manifolds!

 

[bmaahs]

Mr Viper 700 - I wish I would have looked at your post before I pulled my jugs.....
My manifold was indeed cracked - right where you said it would be.

When I initially posted I didn't realize how big the oil tank was - thought what you could see was all there was.
So - in hind sight - I don't think the wife ran the sled out of oil.

I took photos of my top end - pistons had some discoloration - is that anything to be concerned about?
Cylinders didn't have any vertical scratches - but the cross hatch pattern wasn't visible in spots.
Thinking of taking the cheap route and doing rings, pins and bearings and honing the cylinders....

 

[roudyroy1]

looks like you have some blow by on the pistons. wash the cylinders with hot soapy water and a scotch bright to break the glaze, i'm sure the cross hatch is still fine. spec out the pistons, replace if necessary, re-ring it and should be good to go. that manifold should be able to be welded too.

 

[mrviper700]

Mr Viper 700 - I wish I would have looked at your post before I pulled my jugs.....
My manifold was indeed cracked - right where you said it would be.

When I initially posted I didn't realize how big the oil tank was - thought what you could see was all there was.
So - in hind sight - I don't think the wife ran the sled out of oil.

I took photos of my top end - pistons had some discoloration - is that anything to be concerned about?
Cylinders didn't have any vertical scratches - but the cross hatch pattern wasn't visible in spots.
Thinking of taking the cheap route and doing rings, pins and bearings and honing the cylinders....
]

that will be all it needs. weld both the bottom and top of exh. manifold, youll be good to go!

 

[bmaahs]

Just to clarify.... weld where the crack is (obviously) then add some weld over the other 3 spots where a similar crack could occur - (where the outside pipes join the center pipe).

 

[mrviper700]

weld it from original seam weld to the front as marked, do the same to the top as it will eventually crack so just do both sides and be done with it. I beadblast the seams first so they are clean and weld up good with a mig or tig,either work fine.

 

[bmaahs]

Thanks again