Stihl MS460 Magnum problems

[2100hpS10]

I have a Stihl MS460 Magnum. It is a 2006 model that has only cut down 2 trees since new. I put it in a Stihl shop 6 months ago and had it tuned up. I cut a small tree down with it and began to be hard to start. I checked the compression on it and it was 90psi. I just can't believe this engine is bad already.
What causes low compression on so little run time?? I only use Stihl oil and mixed gas correctly! The saw has not run hot at anytime. I checked the cylinder and piston and it has no scoring on them. I have read online that Stihl had problems with this model and discontinued it. What do I need to do with the saw?

 

[user 122190]

It does sound dubious that the compression can be so low on such a relatively new saw. Can you support the weight of the saw by holding just the pull rope?

 

[bwalker]

Are you sure your gauge is accurate? 90psi with no scoring and a saw with almost no run time doesn't add up.

 

[huskihl]

That’s one of the best saws ever made. It lasted from the 046 through the 460 and now through the 461 with only changes to the motor. I’ve never heard anyone say there were issues with the 460.

If it only has 90 psi, either your gauge isn’t correct or a ring is broken on the piston.

 

[rocketnorton]

decomp
try a plug in the hole

 

[president]

decomp
try a plug in the hole

T1

 

[3000 FPS]

Yep I have a couple of those 460's and they are great saws and run very good with no issues.
I am surprised that it would even run with 90 PSI. You need to double check the gauge you're using.

 

[2100hpS10]

Hi all,
I just found out that my saw was loaned out while I was at work overseas. I contacted the person that used it and he said that the saw ran hot. I don't ever loan my tools out and a family member did this. I am really pissed!!
After pulling the exhaust off just now I found the cylinder scored. So this explains the low compression.
So now, I guess I will have to get a cylinder/piston kit. I just got off Ebay... what do you think about the Hyway Titanikel 52mm popup piston kit for the MS460?

 

[user 122190]

Hi all,
I just found out that my saw was loaned out while I was at work overseas. I contacted the person that used it and he said that the saw ran hot. I don't ever loan my tools out and a family member did this. I am really pissed!!
After pulling the exhaust off just now I found the cylinder scored. So this explains the low compression.
So now, I guess I will have to get a cylinder/piston kit. I just got off Ebay... what do you think about the Hyway Titanikel 52mm popup piston kit for the MS460?

Loaned out, and without your permission? Someone needs a good cane beating.

I don't know squat about Hyway Titanikel Chainsaw Cylinder kit, but my instincts are to stay with OEM.
I wouldn't be trying to save money in resurrecting this great saw. Get OEM and restore the saw back to its glory.

 

[3000 FPS]

If I was to do aftermarket on your MS460 I would go Hyway on cylinder and oem on piston. Or you could try and clean up the cylinder with acid and scotch brite. You can do a search here on how to do that. Lots of info.
I would try cleaning up the cylinder first.

 

[trains]

Hi all,
I just found out that my saw was loaned out while I was at work overseas. I contacted the person that used it and he said that the saw ran hot. I don't ever loan my tools out and a family member did this. I am really pissed!!
After pulling the exhaust off just now I found the cylinder scored. So this explains the low compression.
So now, I guess I will have to get a cylinder/piston kit. I just got off Ebay... what do you think about the Hyway Titanikel 52mm popup piston kit for the MS460?

Person who loaned out the saw without your permission should buy you a new genuine stihl piston and cylinder kit, base gasket and gudgeon bearing.
let them take up the expense with the idiot who ruined your saw.

 

[Wood Doctor]

Whenever I loan a saw out to a person who seldom if ever uses a chain saw, I kiss it (the saw) good bye. It will likely come back dead as a hammer, or the saw will be stolen by someone I thought was my friend.

 

[joe25DA]

I’ll let my dad or cousin borrow. They have good saws and tools and rarely ask. When they do I don’t worry. I don’t loan any tools to anyone else. If it’s an emergency I feel the need the tool goes with the owner/operator. When my father in law occasionally asks to borrow something I run to harbor freight and get the Chinese junk they sell, no loss there and it’s certainly cheaper than losing a quality tool/saw. My stuff is mostly older high end not easily replaced. Hurt feelings will pass.

 

[2100hpS10]

You are all right about my situation. I never loan my tools out, as I do buy first quality tools. My immediate family will not loan out nothing of mine anymore... it's done.

Person who loaned out the saw without your permission should buy you a new genuine stihl piston and cylinder kit, base gasket and gudgeon bearing.
let them take up the expense with the idiot who ruined your saw.

What is a gudgeon bearing? Do you think that the crank bearings need changing?

 

[2100hpS10]

If I was to do aftermarket on your MS460 I would go Hyway on cylinder and oem on piston. Or you could try and clean up the cylinder with acid and scotch brite. You can do a search here on how to do that. Lots of info.
I would try cleaning up the cylinder first.

I think it's too far gone for a cylinder clean up. Can it be bored 2mm to accept a new 54mm piston?

 

[3000 FPS]

I think it's too far gone for a cylinder clean up. Can it be bored 2mm to accept a new 54mm piston?

No you cannot bore it out. There is a nikasil plating on the cylinder and once it is removed the cylinder is done for.

 

[huskihl]

I think it's too far gone for a cylinder clean up. Can it be bored 2mm to accept a new 54mm piston?

Can you post up a couple pics of your cylinder? I’ve got used 460 cylinders. I’d rather not outright sell the cylinders, as I use them for building 044/046 hybrids, but if I knew I could clean yours up, we could work out a trade. All you’d need then is a Meteor piston and you’d be back to oem quality

 

[trains]

You are all right about my situation. I never loan my tools out, as I do buy first quality tools. My immediate family will not loan out nothing of mine anymore... it's done.

What is a gudgeon bearing? Do you think that the crank bearings need changing?

Gudgeon bearing is another name for the little end bearing, or the bearing up with the piston end of the conrod/ engages with the piston wrist pin.

Most instances, no the crank and big end bearing will be ok, and its just the piston/ cylinder that needs replacing, but I always do the bearing up on the piston end when replacing a piston.

 

[cookies]

I put a meteor kit into the one I fully rebuilt , I had to dremel the cylinder ports to remove casting flaws and excess nikasil, squish was something like .028 out of the box after cleaning the base with a gasket. The saw is a absolute beast and requires the decomp and D handle so your fingers, elbow and shoulder are not destroyed starting it. The meteor piston weighed over 20 grams heavier than the scored oem i removed, if i pull that cylinder again im sticking a oem or weismic back in its place and if you get a aftermarket cylinder i suggest getting a oem piston. Use a oem wrist pin bearing and oem wrist pin retainer clips in whatever you decide.
And I 100% agree those responsible would be chastised to great extent and shown a dealers quote of the repair cost with requests to cover the parts then sent copies on birthdays, christmas, anniversaries, posted on social media asking other friends/family how they would handle it so its on full display then likely frame it to hang in full view as a reminder so nothing is ever loaned out again on your behalf.

 

[Oletrapper]

Hi all,
I just found out that my saw was loaned out while I was at work overseas. I contacted the person that used it and he said that the saw ran hot. I don't ever loan my tools out and a family member did this. I am really pissed!!
After pulling the exhaust off just now I found the cylinder scored. So this explains the low compression.
So now, I guess I will have to get a cylinder/piston kit. I just got off Ebay... what do you think about the Hyway Titanikel 52mm popup piston kit for the MS460?

You need to read your very first post! Either you did check things or you didn't!
"I checked the cylinder and piston and it has no scoring on them." I'm done with this one. Seems to be blowing smoke to me. jmho OT