Ms460 My First Project Saw

[TINYHULK]

Got two barn find saws some months back. A Ms460 and Ms440. Ordered a basic set of parts and tools for testing and finally got into them today. This thread is just for the Ms460, I will make another thread once I get a little bit deeper into the 440. The home owner said her uncle went through them and said the engines were trash and have been sitting for some years. The saws had the brutal lives of being a rental. So far here are my findings:
1. Lots of missing parts of course. Pulled the exhaust cover and the piston looked surprisingly clean with no transfer.
2. Fitted a recoil on it and pulled it over, no spark.
3. Compression test with innova tester showed 90psi wet. Didn’t want to run a dry test at first since it’s been sitting for so long. Felt really hard to pull over for just that much pressure.
4. Carburetor was full of old gas but surprisingly there was still fuel pressure at the carb as I was pulling the carb off the lines.
5. Performed vac/press test (my first one ever) impulse line was rock hard and leaking, I flipped my stihl adapter over and plugged the line manualy. Put Rubber stihl gasket on the exhaust and found the crank seal on the clutch side was leaking when I sprayed oil on it. I see a bearing not a seal on this side but there’s a snap ring that looked to be in the right place but the bearing looked to be pressed out. Didn’t hold pressure or vacuum well, leaked down slow and steady.
6. The clutch was shot but I didn’t see any other remnants of parts in there. That side of the saw was filled with oil like the leak was there for awhile. Checking for play in the crankshaft it felt pretty tight. Had almost no up/down wiggle and none side to side.

Never took one of these a part to this extent. I have an automotive background so I’m very good mechanically.
Current shopping list is:
1. New carb (any suggestions?)
2. New coil (any suggestions?)
3. Impulse and fuel lines (already have)
4. Clutch and oil pump

Not sure what the best plan of attack is on this leaking seal/crank area so I’m looking for suggestions/advice. Do I have to split the case and do the bearings or should I since I’m this far into it? What is missing/out of place on that clutch crank seal area? I have to get a long t27 bit tomorrow since the stihl chainsaw wrench doesn’t fit in the narrow holes of the cylinder aswell as some parts cleaner. I have a Walbro carb rebuild kit aswell as an aftermarket carb just for testing purposes. Thank you all for your help!

 

[TINYHULK]

Here’s the clutch bearing

 

[Maintenance Chief]

I always rebuild the factory carburetor, they rarely fail do to age. Just check the end of the mixture needles for signs of hamfisted tightness.

 

[TINYHULK]

Got the cylinder off today and here’s what I found.
Cylinder looks pretty good. Got some lines but nothing my finger nail can find. Piston is tired and the rings seized in the piston on the exhaust side. Bearings are grinding so I’ll need to replace them with the seals. Crankshaft itself felt fine but there is evidence of it running real hot. Should it be replaced because of that?
Any reason why I can’t/shouldn’t clean this cylinder?

 

[Moparmyway]

Cylinder looks fine, a little scotchbrite will give it a nice finish.

Looks like the piston and rings are going to need to be replaced

Im putting down my phone and picking up the grinder and a 500i cylinder right now !!!

 

[TINYHULK]

Just realized I never posted these pictures of the crank. The bluing on the crank is concerning to me. It doesn’t seem to have too much play but it definitely got too hot. Is the crank ruined because of this?

 

[Moparmyway]

No, I’ve used and am still using blued rods, haven’t had any issues, and I’ve yet to even hear or read of any actual issues.

To me, rings sticking, rods blueing, piston scoring & transferr …….. all lack of good oil. Either junk oil, not enough oil, or both. Yes, lean running without enough fuel can also cause some of those issues, but said lean conditions come with running issues and the motor, if it’s shut down and not ham fisted into finishing, will be just fine with good oil. I’ve even seen rot gutt gas run just fine with 32:1 good oil without causing any damage or issues in many different 2 strokes, including our beloved chainsaws !!

My advice based on over 40 years of working on chainsaws ……. Pick a good oil and run it at 32:1-40:1.

Back to grinding ………..

 

[Moparmyway]

Here’s the clutch bearing

Looks like it’s going to need a new brake band

 

[TINYHULK]

I’ve gone to 40:1 red armor in all the company saws and planned to run 32:1 dominator in the ported saws.

yeah lol, the clutch was completely blown apart and the brake band was gone. I’ll have to split this case and do the bearings/seals but getting to save the crank and cylinder is awesome! I hear a lot about non-limited coils and different/better walbro carbs for these saws. Any suggestions?

 

[Moparmyway]

Personally, I’d just put together what’s there and run it. You’re not going to be running this at GTG’s, it’s a worksaw, no ?

A mild porting and a good muffler mod will make you grab this saw quickly, it’s known to be dead reliable and very strong, especially if tickled a little bit by a couple of burrs.

If you’re thinking about using this as a playsaw, there’s better choices out there for playing around with. That being said, to me, only the 500i can stand up to the daily grunt of commercial use that the 046/460 can. Stihls are worksaws !!!

 

[Maintenance Chief]

I used blued cranks in my saws and still dont have any problems with them yet.
Heat pretty much destroyed all the seals and rubber parts though.
One bit of advice though, clean everything like its gonna be used in a doctor's office. You can miss a blocked impulse port or a small crack if everything isn't absolutely clean.