Need help swapping out cylinder and piston on old MS 460

[Sunrise Guy]

OK, what special tools do I need? Before I start, I want to know of any special jigs, ring compressor clamps, etc. I should buy. What will they cost? I have been told that I can buy a big bore cylinder from Baileys. What size do I need? Any other info is appreciated.

If you just want to rag on my lack of knowledge of saws, here, don't bother. I'm going to learn by doing, and if you don't have anything helpful to offer me, don't bother posting some #$^&^ here.

Since I just bought a new 460, and have my 440 as a reserve, it won't be the end of the world if I crap out the old 460. However, I am mechanically inclined, and have rebuilt carbs, and done small engine repairs, etc., in the past, so given the right advice, I think I'll be fine.

Thanks, in advance.

 

[THALL10326]

OK, what special tools do I need? Before I start, I want to know of any special jigs, ring compressor clamps, etc. I should buy. What will they cost? I have been told that I can buy a big bore cylinder from Baileys. What size do I need? Any other info is appreciated.

If you just want to rag on my lack of knowledge of saws, here, don't bother. I'm going to learn by doing, and if you don't have anything helpful to offer me, don't bother posting some #$^&^ here.

Since I just bought a new 460, and have my 440 as a reserve, it won't be the end of the world if I crap out the old 460. However, I am mechanically inclined, and have rebuilt carbs, and done small engine repairs, etc., in the past, so given the right advice, I think I'll be fine.

Thanks, in advance.

You don't need many tools. A T-27 long driver, a ring compressor, small screwdriver, which you can buy all at Baileys for a few bucks. The thing about your saw is you need to get it pressure/vac tested either before you tear it apart or after you re-assemble it. You need to make sure you don't have a crankcase leak or you will fry that cylinder again. Any shop should test it for no more than 20 bucks and its well worth it. This insures your new overhaul job will last. If you just install a new cylinder and piston without the tests you risk frying it again. So get it tested..

 

[Lakeside53]

Get a service manual... explains all...

 

[THALL10326]

Get a service manual... explains all...

Aww the master points out the best tip of all, so true,

 

[Tree Sling'r]

Since you have a new 460 and 440, you could always save money and use the blown one for parts for both.
I am not a big fan of the BB kits, OEM is not cheap, but Mahle is the best.

 

[Dok]

Glad to see you decided to fix it yourself! Look for the "Beg For Manuals" thread and ask for a service manual there. If you have any questions/problems you will get all the help you need here.
Dok

 

[THALL10326]

Since you have a new 460 and 440, you could always save money and use the blown one for parts for both.
I am not a big fan of the BB kits, OEM is not cheap, but Mahle is the best.

I'm with ya, OEM for me only. Thats not to say big bore kits from Baileys aren't up to snuff, I know they sell a bunch of them and many like them. I'm just a firm believer in OEM parts, never had a issue with them at all.

 

[Lakeside53]

Stihl OEM rings always.... Soooo much better at brake-in and longevity.

 

[Sunrise Guy]

Glad to see you decided to fix it yourself! Look for the "Beg For Manuals" thread and ask for a service manual there. If you have any questions/problems you will get all the help you need here.
Dok

Well, this is certainly starting off much better than my previous post about this saw. I will have the Stihl service guy do the pressure/vac test, as advised, after it's reassembled. Admitting my ignorance of this saw, here, won't the fried piston and cylinder keep the test from accurately telling me if I have a crankcase leak? I mean, won't pressure be lost because of the pitted cylinder and piston?

I do have the 440 service manual. That should do for the install of the 460 piston and cylinder, right?

Thanks, again, guys.

 

[Lakeside53]

A fried cylinder will have no effect on the pressure/vac test. yes, your 440 manual will be close enough except for torque settings.

 

[Sunrise Guy]

Another thing, here: It was the Stihl service guy who told me that parts, alone, were going to be $400. I trust this fellow, he seems to be a straight shooter and others have told me he's knowledgeable. In light of the $400 outlay for parts, are you guys still thinking this is worth it?

 

[THALL10326]

Well, this is certainly starting off much better than my previous post about this saw. I will have the Stihl service guy do the pressure/vac test, as advised, after it's reassembled. Admitting my ignorance of this saw, here, won't the fried piston and cylinder keep the test from accurately telling me if I have a crankcase leak? I mean, won't pressure be lost because of the pitted cylinder and piston?

I do have the 440 service manual. That should do for the install of the 460 piston and cylinder, right?

Thanks, again, guys.

Not at all. Its merely sealing off the exhaust port and putting an adapter in place of the carb and pumping a bit of air in the crankcase and applying some vac with a set of guages. The guages will indicate whether there's a leak in the crankcase. Your scored piston won't matter as the exhaust is sealed off during the test and the adapter seals off the intake in place of your carb. Its really best to test it after you re-assemble it to insure the base (cylinder) gasket is air tight after your work.

 

[Lakeside53]

well... it's closer to $300 (plus tax if you have it).


yes, if the rest is in decent shape - it's an $800 saw new, and a used saw with a new piston and cylinder will pretty much run like new.

You could sell it for say $200 and buy a new one though...

 

[Sunrise Guy]

well... it's closer to $300 (plus tax if you have it).


yes, if the rest is in decent shape - it's an $800 saw new, and a used saw with a new piston and cylinder will pretty much run like new.

You could sell it for say $200 and buy a new one though...

I guess there must be more wrong with the saw because I asked the fellow if the parts could get any less expensive. He held to the $400. I will get a detailed parts list from him when I pick the saw up, after he tests the pressure. I'll post what he says I need, and then get your opinion, again, on the advisability of a diy job. Thanks.

 

[Lakeside53]

MSRP (NW) P&C $302... Gasket, $3.25.

Ask for cash discount - he's got plently of margin.

 

[ZeroJunk]

There is an OEM kit on eBay for $215 in Canada. $15 shipping to US

 

[andrethegiant70]

Well, this is certainly starting off much better than my previous post about this saw. I will have the Stihl service guy do the pressure/vac test, as advised, after it's reassembled. Admitting my ignorance of this saw, here, won't the fried piston and cylinder keep the test from accurately telling me if I have a crankcase leak? I mean, won't pressure be lost because of the pitted cylinder and piston?

I do have the 440 service manual. That should do for the install of the 460 piston and cylinder, right?

Thanks, again, guys.

Well, NOW can we pick on you?

Kidding, of course... sorry your first post was difficult.

 

[highsiera]

for a ring compressor, what some folks do, myself included, is take the plastic cap from a can of wd-40 or spray paint, cut top top off so you have just the band. Then cut the band so you have a 2" circle of flexible plastic. Next cut the band so it with slide over itself and you can adjust the inside diameter.
Once you have the piston installed on the rod, the c-clips in and the rings installed, lube everything liberally with straight 2 stroke oil (some guys use 30wt) and slide the sleeve you made over the top of the rings. Now gently tighten a decent size hose clamp over the sleeve and begin to compress the rings.

go slow and MAKE SURE THE GAPS IN THE RINGS ARE CENTERRED ON THEIR TINY PINS IN THE PISTON.

tighten gently until the band is flush with the piston. leave a tiny bit of piston showing above the rings to get the cylinder started. lube the heck out of the cylinder.

Now in a quick and gentle motion, push the cylinder down on the piston with loosening the clamp just a bit so your sleeve will slide down towards the bottom of the piston skirt.

DO NOT TWIST THE CYLINDER AS YOU PUSH, A RING COULD GET CAUGHT IN ONE OF THE PORTS

when you are confident both rings have cleared/ enterred the piston, remove the clamp, pull out your sleeve, and slide the cylinder the rest of the way down.

oh, and don't forget to install the cylinder gasket before all these steps. I have, twice. Usually realize it as I'm zipping the sleeve out...

soft hands, little bit of concentration, no fancy tools, mucho gratification.

I also install the intake boot on the cylinder first, things get tight in there once you bolt it down.

 

[Dok]

I have had good results with the Bailey's aftermarket piston/cylinders. If you are going to be using the saw to earn a living then go OEM. Otherwise the Bailey's will be fine.
Dok

 

[timberwolf]

:agree2:

BB kits are just fine for the average user, and a little porting work on them just to clean things up can make a big difference.

Not pushing porting on a first go rebuild, but do a little reading on the subject. Keep in mind though I'll port anything that I can get my hands on right from the farm tractor to pepper mill on the kitchen table.