050 051 075 076 Info Thread

[Rockfarmer]

On a rebuild or new seal install the oil pump piston worm is no big deal. I should have said on assembly of new or used one it’s critical that it turns. I’ve forced them in where they wouldn’t turn and it turned into a shetshow. I actually had to press the brass carrier out and replace it and oil piston worm. I think it happened with bad aftermarket parts. There’s two sizes of gears as well and they must match. The fact that you can spin the hub almost freely and it’s oiling fine is all good. Carbon buildup is from the older 2 stroke oils and leaded fuel. I wouldn’t worry about it, the saw will outlive both of us with the right mix. If you can hold the saw by the recoil rope handle and it doesn’t drop or drops very slow then your compression is 140 or better. New rings and a piston polish will get a good bore back up to 160+ and she will start on first pull cold. They have a new nykasil lined cylinder I want to try. We have great luck with them in the sleds as there is no piston transfere. We actually blew one up by running the injection tank out of oil. Waited an hour to cool down, got oil, mixed the gas and filled the oil tank. Started rocking the seized motor back and fourth. Got it turning over and started it!! It ran great! Low comp at 125 but still ran and we made it 100 miles home. That was a liquid motor though it will be interesting to see how it holds up to the heat of fan cooled. I’ve rambled enough for another 3 months lol, cheers!

 

[PogoInTheWoods]

Don't want to be a buzz kill, but...

That bearing looked pretty nasty and full of debris to me. I sure hope it was cleaned thoroughly with brake or carb cleaner and spun freely before the seals went in. Think I would have split the case to ensure it was still serviceable before worrying about the oiler.

 

[Rockfarmer]

If a motor runs and there’s no bad sounds (stethoscope very handy) why split it just for the sake of cleaning it. Any howl, sure just replace the bearing. I toss em all the time, why go through all that for 17$. Pogo how many old saws you got kickin around that run just great!? Split em and their going to look just like that! Respectfully sir if it ain’t broke don’t fix it!

 

[PogoInTheWoods]

Saws I tear down with bearings like that usually get new bearings, (or at least a serious bath). Bad bearings eventually translate into worse bearings and much larger inconveniences than replacing them in the first place.

I hope they were at least hosed down real well before reassembly.

 

[Rockfarmer]

Agreed. Bearings can do funny bad things. I’ve seen races turning in cases, ruining the case. I’ve seen inner races spinning on cranks ruining the bearing and once or twice a good race spinning on worn crankshaft. All have to be mic’d And tolerances checked before just changing the bearing. If you feel ANYTHING while turning the bearing it’s junk. IMHO

 

[rebuildinSawin]

On a rebuild or new seal install the oil pump piston worm is no big deal. I should have said on assembly of new or used one it’s critical that it turns. I’ve forced them in where they wouldn’t turn and it turned into a shetshow. I actually had to press the brass carrier out and replace it and oil piston worm. I think it happened with bad aftermarket parts. There’s two sizes of gears as well and they must match. The fact that you can spin the hub almost freely and it’s oiling fine is all good. Carbon buildup is from the older 2 stroke oils and leaded fuel. I wouldn’t worry about it, the saw will outlive both of us with the right mix.

Ok great. This is just a tuneup not really a rebuild. Gone and replaced a few minor parts on it here and there but 99% of the saw is great. Pulled and repainted the muffler because it had a little bit of rust so why not make her look great again.

If you can hold the saw by the recoil rope handle and it doesn’t drop or drops very slow then your compression is 140 or better. New rings and a piston polish will get a good bore back up to 160+ and she will start on first pull cold. They have a new nykasil lined cylinder I want to try.

Nice trick i'll have to try this tonight. Normally she coughs after 2 pulls on choke then starts next pull (if i don't forget all the switches!). I had a bit of oil lying in the cylinder/case after cleaning it all out and when i started it, man, the compression was epic. Started the pull at point of max compression as usual but as soon as it turned it ripped the starter rope straight out of my hand..... Had to get gloves to get enough grip!!
Now i want that compression all the time! I've been thinking about re-ringing but i really don't want to pull off the cylinder if i don't need to so i'll give it a bit of a run first. I've only got a home made compression gauge and it reads 120psi-125psi on that (take that with a grain of salt as i don't have anything to calibrate against) which matches my newly rebuilt 038 magnum. So either the magnum is toast already or the compression is great.

We have great luck with them in the sleds as there is no piston transfere. We actually blew one up by running the injection tank out of oil. Waited an hour to cool down, got oil, mixed the gas and filled the oil tank. Started rocking the seized motor back and fourth. Got it turning over and started it!! It ran great! Low comp at 125 but still ran and we made it 100 miles home. That was a liquid motor though it will be interesting to see how it holds up to the heat of fan cooled. I’ve rambled enough for another 3 months lol, cheers!

Amazing. Love stories like this... I have one about a hydro-locked diesel that got stripped in the field at ran home on 3 cylinders hahaha. rod was bent like a boomerang.
I put a nikasil aftermarket top end in a 038 magnum recently, it hoons along just fantastic and pulls great. I guess time will tell if its much good but for $50 all said and done i'm not complaining!!!

Re: bearing crud: Yep cleaned it out with parts cleaner, i was happy enough with it. Saw was my old mans and its been sitting around since he passed away at 63 a few years ago. He had it since new so i know where it has been and how it has been used (taken care of very nicely). All the covers are in top notch. It has a lot of sentimental attachment for me as we cut many many cords together. So I want to get it running top notch & really don't want to split the case if i don't absolutely have to & i'd probably just make a mess of it

The old man only ever ran a 25" hard nose bar and it hogs really nice with that but i've got some bigger wood to cut so i got a 36" hard nose for it (.404 full comp). It was struggling to pull the 36" a bit through hardwood (just bogs down far too quickly) which is what caused the start of this investigation! Running the 076 is hard work but is an absolute joy & very nostalgic.





I just picked up a 024 that needs a new top end as something grenaded in it and is disgustingly messy so i might split the case on that as a practice run.

Sorry for the life story! Hahaha

Cheers

 

[Rockfarmer]

That my friend is a Super. If it has the walbro carb it’s worth a lot ( to me )!! Nice saw! It should run a 4’ bar no probs with skip tooth or semi. Sold one to a guy in Idaho that said he was going to try 8’!! Might deserve a top end. Anything under 150 hot with throttle wide open is less than 100%.

 

[rebuildinSawin]

That my friend is a Super. If it has the walbro carb it’s worth a lot ( to me )!! Nice saw! It should run a 4’ bar no probs with skip tooth or semi. Sold one to a guy in Idaho that said he was going to try 8’!! Might deserve a top end. Anything under 150 hot with throttle wide open is less than 100%.

Yes certainly is a super & it has the walbro carb. Here (down under) the 076's don't seem to be worth terribly much and there a bunch of really beat up ones out there but this one isn't going anywhere! :-D

Ah yes, i need to test while hot, i've only done compression testing while cold so far and i don't think the rubber tubing i'm using as a coupling helps... tends to blow itself off over about 120 psi hahahahaha. Some improvements definately are in order to the DIY gauge and calibration is badly needed.



8'. Thats incredible. It's bad enough sharpening the 3' bar! At what length would you go skip chain?

Cheers

 

[Rockfarmer]

I think a hot test will give you a lower reading than cold. All oils and fuel has burned off and evaporated leaving no liquids (liquids in cylinder obviously give higher readings). The Walbro carb is bigger than the tilly and gives a bit more fuel plus the velocity of the 12 mm stack gives more punch. Love it!! Right around 36-42”+ you can start thinking about semi and full skip. I have a hard nose on an 090 but wouldn’t dream of running it on any other saw, just robbing power. Also even the cheapest bar and chain oil is 100 times better than the stuff I’ve heard of used and for the 7$ a gallon it will last a while and so much better for chain, bar saw and operator! I love the square chisel chains but round chisel will hold an edge, cut as good and not bog her down as much. Of course I take my rakers down waayyy to far but that’s why I run 111 cc’s!!! I love how you guys get creative with tools. The shipping to Aus is more than the tool costs! Also I’m cutting green hardwood which is a heck of a lot easier than those petrified dried out hardwood logs your playin with!!

 

[rebuildinSawin]

Ah yeah those old sh**ts in the photos are just the old rounds i sit stuff up on to split, sometimes i get mad with something that won't split and take the saw to it hahahaha

Yes unfortunately the only cheap tools we can get are those direct from china, hit and miss... Most local tool sellers just sell re-branded chinese stuff for 4x the price.
Bar oil is also expensive here but it's far better to pay that tax then to deal with cleaning the mess of used truck oil and woodchips out of the saw... ergh...

I've been taking the rakers to 0.8mm on the RSC .404 which seems ok, and i think is stihl recommended spec... not much experience this this though. It doesn't seem too grabby. I'm not totally happy with the 36" hard nose to be honest... ahhh well....

Re: compression, i'm not a mechanical expert by any means but was thinking hot would be better due to metal expansion and the rings seating to the cylinder wall? I have also read somewhere a while ago you should do the compression test at WOT, i'm guessing this is to make sure the max fuel amount is misting in & fuel is more dense than air...
I guess the main thing i've done in the past is the difference between oil compression and no oil to see how well the rings are worn, but i wouldn't have any idea what is a good/bad number!

 

[Rockfarmer]

Well I am following you for sure. I know when oils in there the reading goes through the roof or vapor locked as in waayyy to much gas and you can’t pull it over. I’ll give a saw a hot cold test tomorrow for grins and put this to bed. Getting late here,... cheers !!

 

[Rockfarmer]

So here’s what I found, fwiw,... 051 with a fresh rebuild, caber rings with a .08 gap and perfect cylinder. Cold the compression was 192!! Oh my I cut one round and let her idle some and retested and came in at 176. Both done at wot. So there you have it, 16 lbs difference on my test. Btw this 051 think it’s an 076, I want to race em side by side

 

[rebuildinSawin]

View attachment 615149 View attachment 615147 View attachment 615148 So here’s what I found, fwiw,... 051 with a fresh rebuild, caber rings with a .08 gap and perfect cylinder. Cold the compression was 192!! Oh my I cut one round and let her idle some and retested and came in at 176. Both done at wot. So there you have it, 16 lbs difference on my test. Btw this 051 think it’s an 076, I want to race em side by side

Holey moley!
I'll take one of those!

Nice work sorting the cold vs. hot sir!

 

[Rockfarmer]

I think the 051 kind of gets a bad rep. It’s quite a saw. They seem to vibrate apart like an old Harley but if you can get one together right it will do you well. The crank obviously is the same as the 076. Force=mass x acceleration. True the piston is 6mm wider in the 076 but the weight of the rotating crank is the same minus the extra force subtracted to move bigger piston back into compression stroke. Also take the 1115 series saw say a Super is also 89 cc’s but the crank is 2 oz lighter. If you just weighed the crank lobes I but they are 20% heavier on the 1111 saws. I’ll cut a couple up to see but that rotating mass (crank lobes) of the 051 gives it great torque! I had a guy buy an 051 off me, offered him the 076 same price and he wanted the 051! Now he wants me to rebuild his old one. I have two on the shelf for the same as the rebuild no waiting but he wants his old saw. I guess we like what we like

 

[Ted Jenkins]

Be careful what you say about my 076 as it can keep up. I have not had such a great luck with compression releases. My current cylinder was used, but otherwise in great condition except for the threads for the compression release. It was plugged. I have been starting it without a release, but some times it can be a hand full to start. A 051 just plain runs different than a a 076 or 075. Certainly all of them in my opinion are great saws and better in some ways than the MS newer ones. However they are heavier period. Power delivery of the 051 to the 075 is right away noticeably different, still great but definitely different. Thanks

 

[Rockfarmer]

Hey Ted, agreed but just pointing out the value of the 051! As far as weight the 880 is 22 lbs as is the 076. The difference is 10 cc’s but the 076 can be tweaked to spin over 13,000 rpm, 4,500 over stock and will take that 880 to school! The advantage is a more durable magnesium case and very little plastic. The 076 can last 40 years where the new saws well we just don’t know. As far as the comp release the 051 just has a terrible one and I usually just plug them. Them 076 has a good one but as you said needs some care on assembly. If you look at a new one there is some thick heavy red locktight on the threads which cooks off and hangs onto the threads in the jug head as I have never seen it on one I have taken out. It leaves a gummy rounded off thread look in the jug that’s hard to clean. I have run a tap through a few grinding the tap point to square so as not to mess up the port. Also very important is the sealing ring on the end of the release. Without that the release won’t seal right. The comp release does work well if everything is right. The port can be cleaned if the cap screw is removed and a very small finish nail tapped though to push out carbon buildup into the cylinder. A long cleaning in a ultrasonic cleaner will loosen up all that carbon and clean her up nice! Make no mistake sir I do love the 076!

 

[Ted Jenkins]

Rock have not had a 051 in my hands for probably twenty years, but I remember how well it melted through larger pine logs. I was always looking for an excuse to put down a smaller saw. Then one of my helpers dropped a good size Oak on it so was left with a 056 super which worked well. The 056 ran a little smoother, but it as you pointed out it was not the torque monster that a 051 was. Now that I have gotten the taste of larger cubic displacement with larger logs not sure what I was thinking for those years. I thought that my 070 075 076 would just collect dust, but not any more. Keep the chips flying. My thinking was use only one or two saws a day because a big bore is too heavy. Thanks

 

[diesel&coffee]

POST DELETED

SORRY - BAD JOKE.. MY KEYBOARD WAS HACKED WITH PLOT...

 

[happysaws]

Anybody here know the part numbers for the crank seals on an 041Super? Thanks!

 

[bulletpruf]

Picked up a sweet 076 Super from the "other" site. Was advertised as an 075, but it has the oil cap on the side and also has the ears that hold the chain brake handle. Looks like it has the 076 intake as well; need to check that and the carb.

Anyone have any chain brake bits for an 076? Please pm if you do. An 076 Super tag or top cover would be great, too.

Scott