Alright heading into the garage to tear the top-end off. I will post photos of the cylinders and pistons as soon as they are off. Hopefully the cylinders don't need to be bored.
-Mark
-Mark
Well, not off to a good start at all. I took the pipe off and about a cups worth of coolant poured out of it when it was tilted. Not good.
I really hope that the crankcase is not flooded with coolant.
And to make matters worse, one of the lower exhaust manifold nuts is rounded off - the last one needed to be removed for the manifold to come off. There is just barely enough room for my needle-nose vice grips to fit on it but no luck so far. I sprayed it with some CRC Freeze-Off and am letting it sit. If that doesn't work I'll go to the Dremel.
Wish me luck.
-Mark
I really hope that the crankcase is not flooded with coolant.
And to make matters worse, one of the lower exhaust manifold nuts is rounded off - the last one needed to be removed for the manifold to come off. There is just barely enough room for my needle-nose vice grips to fit on it but no luck so far. I sprayed it with some CRC Freeze-Off and am letting it sit. If that doesn't work I'll go to the Dremel.
Wish me luck.
-Mark
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Suprx125
New member
Bummer....Good luck!
Well, I finally got that manifold nut off. Removed the head - cylinders are toast. Cross-hatch only barely visible in the PTO cylinder. The others have vertical marring, probably hard to see in the photos, I don't think honing will fix them. Mag side cylinder has what looks to be part of the piston or rings fused to the wall.
Still trying to figure out how the coolant ended up in the pipe - base gasket perhaps? No cracks in any of the cylinder walls. Any idea how that could have happened? I haven't removed the cylinders yet, but I'm sure the crank case is filled with coolant so the bearings are probably shot. Is it cheaper to have the cylinders bored & re-plated or to buy new?
Any input or thoughts are greatly appreciated.
Thanks,
-Mark
Mag Side Cylinder & Piston:
Still trying to figure out how the coolant ended up in the pipe - base gasket perhaps? No cracks in any of the cylinder walls. Any idea how that could have happened? I haven't removed the cylinders yet, but I'm sure the crank case is filled with coolant so the bearings are probably shot. Is it cheaper to have the cylinders bored & re-plated or to buy new?
Any input or thoughts are greatly appreciated.
Thanks,
-Mark
Mag Side Cylinder & Piston:
Any thoughts guys? Trying to decide if it's better to just buy a recently rebuilt engine, or the parts to rebuild this one. It looks like I can get a rebuilt engine for about 1200-1300, and I suspect parts and a crank rebuild will run me at least 1000...
Thanks,
-Mark
Thanks,
-Mark
super1c
Super Moderator
That comes down to a personal choice. Buying a rebuilt engine could be just buying right back into a burn down not knowing if it was done right. If you do it yourself you know its done right and are sure parts used ect.... If it were me and had the time before the snow i would do the rebuild yourself. If it was middle of season and time is short a used engine would do. Do the rebuild yourself with OEM parts and that engine will go another 10,000 miles. The sled will fall apart before the engine.
super1c said:That comes down to a personal choice. Buying a rebuilt engine could be just buying right back into a burn down not knowing if it was done right. If you do it yourself you know its done right and are sure parts used ect.... If it were me and had the time before the snow i would do the rebuild yourself. If it was middle of season and time is short a used engine would do. Do the rebuild yourself with OEM parts and that engine will go another 10,000 miles. The sled will fall apart before the engine.
I see your point. I still need to find out what caused the engine failure. The way the cylinders are scored I could definitely see how a lack of oil could lead to that; guess I will not know until I get down to the oil pump and see what the situation with that is...
Is there any way to test the oil pump with the engine not running?
staggs65
Moderator
I've bought 2 vipers that had rod bearings go out on the crank and both looked like that.
you'll know once you pull the cyls.
hard to tell from the pics but it looks like your head survived.
here's some worse case pricing as I see it.
you can get renicked exchanges from millenium for about the same price as used cyls.
cyls either way $450 (thats on the high side)
3 new yamaha pistons $300
rings $70
pins and circlips $55
wristpin bearings $55
crank seals, base n head gaskets, waterpump seals $100
good used crank or rebuild on yours $400 (could be less or more, median price depending)
so somewhere around $1400 to rebuild yours right and as Super1c said, you know its right.
Or if you want to cut your losses let me know. I'll give you what you paid for as it sits.
you'll know once you pull the cyls.
hard to tell from the pics but it looks like your head survived.
here's some worse case pricing as I see it.
you can get renicked exchanges from millenium for about the same price as used cyls.
cyls either way $450 (thats on the high side)
3 new yamaha pistons $300
rings $70
pins and circlips $55
wristpin bearings $55
crank seals, base n head gaskets, waterpump seals $100
good used crank or rebuild on yours $400 (could be less or more, median price depending)
so somewhere around $1400 to rebuild yours right and as Super1c said, you know its right.
Or if you want to cut your losses let me know. I'll give you what you paid for as it sits.
staggs65
Moderator
also take some good pics of the inside of all 3 cyls and post
staggs65 said:also take some good pics of the inside of all 3 cyls and post
Will do. Should have them off later today. Like I said the cross-hatch is only slightly visible in the PTO cylinder. However, they all have the vertical scoring as you can see in the photo of the mag side cylinder.
-Mark
Alright. I got the PTO and center cylinders off, sort off. PTO side came off no problem, but the center power-valve is stuck in the cylinder. I've never had a power-valved sled before, but something tells me that they shouldn't be as dirty as the PTO valve. See the photo.
As I suspected - the crank case is filled with coolant.
I think the PTO cylinder is OK to reuse. Lots of cross-hatch visible. There is only one mark - the long one in the photo, and you can just barely feel parts of it, but it is less than 1mm deep. Do you guys think I can get away with just a honing on this cylinder?
Center cylinder is toast - see photos of it and the piston. I've never had so much trouble removing a wrist pin before - I had to pound it out with a socket.
That's all I have time for today, I promised the wife I'd make veal stew tonight!
As always, your thoughts are most welcome.
-Mark
PTO Cylinder Photos:
PTO Rod:
Center Cylinder Photos:
Center Cylinder Piston:
Mag Cylinder - Note Remnants of Ring or Something Fused to Cylinder Wall:
As I suspected - the crank case is filled with coolant.
I think the PTO cylinder is OK to reuse. Lots of cross-hatch visible. There is only one mark - the long one in the photo, and you can just barely feel parts of it, but it is less than 1mm deep. Do you guys think I can get away with just a honing on this cylinder?
Center cylinder is toast - see photos of it and the piston. I've never had so much trouble removing a wrist pin before - I had to pound it out with a socket.
That's all I have time for today, I promised the wife I'd make veal stew tonight!
As always, your thoughts are most welcome.
-Mark
PTO Cylinder Photos:
PTO Rod:
Center Cylinder Photos:
Center Cylinder Piston:
Mag Cylinder - Note Remnants of Ring or Something Fused to Cylinder Wall:
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staggs65
Moderator
you'd be surprised how much of those marks on the second cyl are just remnants of the piston. I'd hone all 3 cyls and inspect them. the nikasil is a lot harder than the aluminum piston. if they dont have deep gouges from broken rings or crank bearings you might have lucked out. Hows the rods feel, nothing flopping around is there?
staggs65 said:you'd be surprised how much of those marks on the second cyl are just remnants of the piston. I'd hone all 3 cyls and inspect them. the nikasil is a lot harder than the aluminum piston. if they dont have deep gouges from broken rings or crank bearings you might have lucked out. Hows the rods feel, nothing flopping around is there?
Well that sounds like good news. Surprisingly - no play in either the PTO or center rods. I'm still trying to figure out how the case got filled with coolant. All I can come up with is a base gasket.
Staggs, do you have any local recommendations on who I can get to hone them?
Thanks,
-Mark
staggs65
Moderator
I use a guy down this way in greene. He does all the crank and machine work for woodys yamaha in topsham. Theres probably someone closer for you but I can give you his info if you want.
staggs65
Moderator
on the coolant, I can see you didnt drain it before taking the engine apart from your pic of the cyl with coolant still at the top. If you took the head off before taking the pipe off and finding coolant in it then I'd suspect you got the coolant in there when you pulled the head.
staggs65 said:on the coolant, I can see you didnt drain it before taking the engine apart from your pic of the cyl with coolant still at the top. If you took the head off before taking the pipe off and finding coolant in it then I'd suspect you got the coolant in there when you pulled the head.
I might need his info. I removed the pipe first, before the head, so that's what worries me. Coolant tank was empty before I started the tear down.
jwhalen123
New member
Hey there, I've got the same sled/engine torn down right now. Mine has 2600-3000mi on it. It was drowned in the big flood we had here in waterbury, vt last year. The water line was up to the windshield and the sled was sitting on a trailer. I got it for free so I'm rebuilding the engine and hoping the electronics survived since most are seal. The spring you showed comes from inside the rubber house coming off the front of the engine/oil pump.. at least that's where I found the same spring during my tear down. Anyways, it looks like I have to split the case to remove the rods. Do I need to have the bearings pressed by a professional or can diy'r with a bearing press change the crank/crank case bearings themselves? I've heard people say that to replace the crank bearings you need to send the crank out... Good luck with your build