Stihl ms 310 rebuild

[mainer_in_ak]

Was given an ms 310 that sat unused for 10 years.
Anybody still tinkering on these old 290/310/390 saws?

It had a stripped bar nut stud, leaky fuel line, and chain-side crank-seal leak. The spur sprocket was chewed up bad.

It ran great though, so figured it would be worth tearing down for a rebuild. The stihl rs chain and 20" rolamatic ES bar was fairly new.

Ported the muffler, probably the most restricted muffler I've ever seen. The gasket had a hump that caught a bunch of carbon as well, so port-matched the gasket.

Cleaned about 1 lb. of gunk out of the saw.

Upgraded plastic caged crank bearings to metal caged skf 6202 C3 bearings.

Upgraded the piston to a lil red barn pop up piston.

Polished the intake and exuahst ports. Its a stihl/mahle cylinder. Good quality, very smooth intake exhaust ports as-is, but polished them anyways.

Advanced the ignition timing 3 more degrees.

Replaced crank seals, impulse line, fuel line and oil line with all new stuff.

Upgraded to an Oregon brand rim sprocket kit.

Weird saw to take apart, but went back together all right.

I used hot soapy water and nylon bristle bush to clean the insane amount of gunk off it, followed by compressed air.

Runs strong. I enjoyed the good aftermarket support for the saw. I'd call it a "semi-pro" after the updraded bearings/higher compression piston and rim sprocket. The walbro carb adjusted easily, doesn't need rebuilding. Started on the second pull after the assembly.

Gonna run it against my echo cs 620pw. At 1/6 the price after upgrading this free under-dog, it feels almost as powerful. I'll time some cuts tomorrow.

Waiting on an Oregon 24" Versacut bar and EXL chain. Should be a good match.

 

[mainer_in_ak]

Will post timed cuts later today. The muffler moded 620 will be a good judge of power.

Hope the 310 under-dog semi-pro beats it......

 

[mainer_in_ak]

Buried in 18 inch Alaskan birch or an equally large white spruce, the improved ms 310 pulled just as hard as the 620pw

The longer stroke and more aggressive ignition timing on the 620 had better low-end grunt.

As long as you kept the rpms high, the 310 cut just as good. The 620 was pulling .050 Gauge and the stihl was pulling that old .063 gauge 3/8 chain. I bet the .050 stuff is lighter chain.

I gifted this ms 310 to my neighbor, who likes stihls. He only has an ms 261, so should be a good back-up saw or for bigger felling/bucking jobs.

I don't need anymore saws, I have enough.

 

[NWWrench]

Thanks for taking time to post, most people throw them away. I like doing the same thing you have with this saw, it feels like an accomplishment at the end of the build and your neighbor will enjoy it and hopefully take care of it for many years to come.
I just did the same type of build with a early 10 mm 044 that was given to me with a failed pto bearing, I dumped a Ben Franklin into it and made a great saw that I gifted to best friend, he will enjoy it.
Ryan

 

[Wood Doctor]

I rebuilt this one and upgraded it to a 390. Here's what it looked like before I started:

It runs today. I do enjoy saving hardware from the landfill, and I did the same as NWWrench. One of my good friends is the new owner. His cousin beat it up before I started.

 

[mainer_in_ak]

Wood doctor,
That's is one gunked up saw. Good on yah, gifting a saw to your friends n family.

Nww,
Good on yah for gifting worked-over saws to your friends n family!


Worked-over chainsaws are an excellent gift.

 

[Wood Doctor]

Wood doctor,
That's is one gunked up saw. Good on yah, gifting a saw to your friends n family.

Nww,
Good on yah for gifting worked-over saws to your friends n family!

Worked-over chainsaws are an excellent gift.

It was in such ugly shape I almost begged off and threw it away. In addition to what you see here, it had no compression or spark. I found a mud dauber nest inside the pull cord housing. A few small worms crawled out. I removed close to a quarter pound of sludge. I told LOML about it and she said, "Don't show that mess to me. My stomach is turning."

 

[mainer_in_ak]

Wood doctor good on yah for not tossing it! Scalding hot water some dish detergent and a nylon bristle brush cleans that German Tupperware purdy good, ha!

That ms 310 was one second behind the 620pw in bar-length white spruce.

The rpms were so high in the cut, it was skipping over the wood in the cut. I had to take rakers down to .0395". Also had to restore the bar groove, it was worn too loose.

 

[mainer_in_ak]

Finally got that EXL chain and versacut 24" bar on the saw. It's a great match and balances the bar perfectly. Helped with some firewood and the neighbor was all grins, bucking the biggest birches he could find.

 

[Wood Doctor]

Wood doctor good on yah for not tossing it! Scalding hot water some dish detergent and a nylon bristle brush cleans that German Tupperware purdy good, ha!

That ms 310 was one second behind the 620pw in bar-length white spruce.

The rpms were so high in the cut, it was skipping over the wood in the cut. I had to take rakers down to .0395". Also had to restore the bar groove, it was worn too loose.

You saw the Pic in post #5 above. Here's is what it looks like after I upgraded it to a 390:

This is the "after" Pic of the restored saw. It runs today.