Stihl MS462C rebuild

[Gman993]

Hi all
I have been member and regular lurker on this forum for about 18 months now but haven't made any posts...... so this is my first.

I have recently been given a Stihl MS462C saw that has had an engine failure due to the air filter not being cleaned and being totally blocked.

I would really like to rebuild this saw and add it it to my 4 saw plan, as it would be my biggest saw and would compliment my MS261C-M, MS181 and Poulin saw very well.

The piston, cylinder and engine cases are all damaged and it also need a new handle, bar and chain (the previous owner kept the bar and chain to use on his new 500i). I was hoping that some of you with more knowledge and experience could advise me whether it is worth fixing this saw? I have also been struggling to find suppliers who sell the parts for the MS462's so any advice on this would also be appreciated?

Below are some photos. The damage to the cases seems the most significant problem to me.

Regards
Graeme

 

[trains]

With a newer saw like that, I would assume your going to have to make friends with a local stihl dealer and go from there regarding parts.

As far as the rebuild, how far are you planning on going re the rebuild, splitting the case and replacing the bearings ?, or just replacing the piston and cylinder etc.
some better pics of the cylinder after removing all the debrits, and wiping out the oil so we can get a better idea of if any ports are damaged when the skirt broke up etc.
edited to add
just had another closer look at the pictures and I think I can see damage to the bottom rim of the cylinder, but on my screen its difficult to make out clearly.

but yeah, repair it, great learning experience and a good saw to add to what you already have.

 

[Gman993]

I expect that piston, cylinder, bearings and seals, handle, bar and chain will need replacing as a minimum.

It looks to me that the biggest problem is that both engine cases are damaged. I assume they will also need replacing.

 

[jltrent]

That is exactly the same catastrophe my local dealer told me he was encountering on those. He said from his experience the piston must start vibe rating back and forth and breaks the skirt off and then you have pretty much a paper weight. He even said from his experience the rods on some were even stretched on the crank. He said he had new software to slow them down that might help. That would be a parts saw to me and hopefully the crankcase is still good. If not give it to somebody else.

 

[Gman993]

I think that the failure of this saws engine was because the air filter was totally blocked up as it hadn’t been cleaned in a looonnnggg time

 

[jltrent]

I think that the failure of this saws engine was because the air filter was totally blocked up as it hadn’t been cleaned in a looonnnggg time

Generally from my experience a clogged air filter slows them down and run a little rich. It messes with the air/fuel ratio. It being M-Tronic I am it was trying to compensate for that. Still though a mechanical break down like that should not happen on a low hours saw.

 

[trains]

Need to post up some pictures of the case damage.
if they need replacing, its heading into uneconomic repair range.

 

[Gman993]

Case damage :

 

[Gman993]

Another photo of case damage

 

[sean donato]

Near the impulse nipple you can clearly see the damage. At best you may be able to get by with some jb weld to repair the area. Or cleaning it up with a file and hooing it seals. I'd advise at minimum taking the saw completely apart to inspect the case halves throughly and the crank bearings. It has a lot of debris from flying apart down in there.

 

[trains]

Oh, I see it now, missed those in the earlier pictures, they were too fuzzy, not sure why.
Hmm, talk about carnage central.

have heard of some of the earlier ones failing, seems there was an issue with the earlier piston shape/ design and they would break skirts like yours has, cracking would start near where yours has failed, where the skirt radius to clear the crank goes down to make the skirt lower, they would crack along there.

ouchie, what is the date of manufacture on the rear handle if the sticker is still there.

further reading which shows the changes to the piston, and a link to search for too that will bring up a good long discussion about it somewhere else.

https://www.arboristsite.com/threads/stihl-462-update-info.354056/#post-7569682

 

[Lightning Performance]

Looks toasted

 

[Dean-O]

The cost of the OEM parts from Stihl are super high flywheel side crankcase is $350, PTO side case is $330, piston and cylinder is $460. By the time your done getting bearings, gaskets and whatever else you need you could buy a brand new 462 with a 2 year warranty.

It’s a deep hole that you would go down that’s going to cost a lot of money, my opinion is to spend that money on a new saw.

 

[Sierra_rider]

Don't bother with that saw. Sell what good parts are there and move on.

 

[Gman993]

The cost of the OEM parts from Stihl are super high flywheel side crankcase is $350, PTO side case is $330, piston and cylinder is $460. By the time your done getting bearings, gaskets and whatever else you need you could buy a brand new 462 with a 2 year warranty.

It’s a deep hole that you would go down that’s going to cost a lot of money, my opinion is to spend that money on a new saw.

Thank you and that is the conclusion I came too

 

[Gman993]

Don't bother with that saw. Sell what good parts are there and move on.

Thanks. I think that is the way to go too

 

[sand sock]

That is junk. I wonder if you can get it put on the computer at your Stihl dealer and see what happened.
I think you shotat least tear it apart and just understand bits and pieces. How stuff works.

 

[huskihl]

Piss revving, excessive re-calibrating, or running dull chains at excessive rpm. With a worn piston, the piston rocks enough in the bore to hit that flange and it self destructs. This is why they updated the 462 a few years ago

 

[Gman993]

This saw was only a couple of years old and had been used regularly to fell Australian hardwood trees and cut a lot of firewood for commercial sale. The saw ran a 25" bar with tungsten carbide chains. I used the saw to cut a large tree on my property just a few weeks before the engine failure and it pulled hard and cut well.

I have no idea how many hours it had done but when I got it (after the motor destructed) the air filter was almost totally blocked to the extent that I was surprised it would still run. I expect that this would effect the air-fuel ratio. Could this have caused the piston skirt to fail and then damage the internal parts of the cases?

 

[huskihl]

A plugged air filter would’ve helped it if anything. Less air would slow it down and should make it run rich