Stihl MS500i cylinder and piston

[TINYHULK]

I received the saw yesterday! Today was a wash out so I took the opportunity to do some maintenance and give the 500i the love she deserved. As soon as @Moparmyway said he would do this build for me I began buying nothing but the best for this saw. Today I tore it down deep cleaned it and took every single piece of plastic, even the orange stop button and dyed all of it graphite black. Added a max flow air intake, wrap handle, WCS clutch cover, and a new 28in sugihara bar. I installed a new primer bulb assembly and new fuel lines as requested. I have two gallons of dominator 2 stroke in stock now and have my 32:1 mixed up and ready for tomorrow! Haven’t got to put it in the wood yet but I am absolutely impressed with this saw already! We have 3 500i’s and this build changes the game on how it feels. I barely touch the throttle and that torque is twisting my wrist. I started it a couple times this morning just to listen to it. After the tear down and everything done to it: primed it and started on the first pull. That never happens after sitting for like 12 hours! Truly amazing and super grateful! Not sure what my job tomorrow entails but this saw will find wood tomorrow!

 

[Sierra_rider]

I received the saw yesterday! Today was a wash out so I took the opportunity to do some maintenance and give the 500i the love she deserved. As soon as @Moparmyway said he would do this build for me I began buying nothing but the best for this saw. Today I tore it down deep cleaned it and took every single piece of plastic, even the orange stop button and dyed all of it graphite black. Added a max flow air intake, wrap handle, WCS clutch cover, and a new 28in sugihara bar. I installed a new primer bulb assembly and new fuel lines as requested. I have two gallons of dominator 2 stroke in stock now and have my 32:1 mixed up and ready for tomorrow! Haven’t got to put it in the wood yet but I am absolutely impressed with this saw already! We have 3 500i’s and this build changes the game on how it feels. I barely touch the throttle and that torque is twisting my wrist. I started it a couple times this morning just to listen to it. After the tear down and everything done to it: primed it and started on the first pull. That never happens after sitting for like 12 hours! Truly amazing and super grateful! Not sure what my job tomorrow entails but this saw will find wood tomorrow!

Nice, it almost looks like the twin to mine...one of my coworkers calls this saw "Lord Vader" lol.

I'm really digging mine...this was a hybrid 500i with 660 piston build that I tried out. There were some teething issues early on with version #2, but this version #2 is looking pretty promising. It's got good chain speed in the cut, but doesn't lack for torque either.

 

[TINYHULK]

That’s awesome! I’ve always been intrigued with the hybrid builds. I grew up in my dads auto shop always hearing about the power of the 383 stroker. They were all old school hot rod guys then I grew up and started doing modern diagnostics lol. I’m new to chainsaw repairs and just starting to do my own repairs and rebuilds. Give it a few years to marry my girl and buy a new house and I hope to get into porting then. We will see what happens with life lol

 

[Sierra_rider]

That’s awesome! I’ve always been intrigued with the hybrid builds. I grew up in my dads auto shop always hearing about the power of the 383 stroker. They were all old school hot rod guys then I grew up and started doing modern diagnostics lol. I’m new to chainsaw repairs and just starting to do my own repairs and rebuilds. Give it a few years to marry my girl and buy a new house and I hope to get into porting then. We will see what happens with life lol

Yeah, I didn't really get into building saws until I bought my house and had a shop space that was permanently mine...now I just need a bigger shop. In my current shop, building saws is a relaxing hobby...back when I was in a small, single car garage without a workbench, working on anything was extremely frustrating.

The "566i" project as I call it, kinda opens up some options as far as port timing and the profile of the top of the piston. A side effect is that the finished 660 piston is 10 grams lighter than a stock 500i piston.

Forgot to post mine, I didn't put as much work into the plastic as you did, just did the top cover to match the Maxflow.

 

[TINYHULK]

Just updating on the saw! I haven’t got to use it much. Been a lot of maintenance days and little prunings around the holidays. I’m finding I like a torquey saw and this thing powers through the wood with a 7 pin sprocket. After the holidays we have a big removal job. 14 white oaks on one property so she will be getting lots of play time then! I do have a question though. All of our saws are stihl, the only ported saws I have is the 500i and my 395xp. What octane gas should I use? Running 32:1 dominator in the ported saws and 40:1 red armor in the regular saws. I was always under the impression that higher octane is better but recently I’m learning that too high of an octane can actually cause a loss of power. Been running 91 octane. Should I go down in octane? Thank you all and happy new year!

 

[Nutball]

I like to run as high as I can find (93 around here) just for good measure since I have heard some knock or whatever in both a chainsaw and my car on the mid grade mix 89 octane. No need to go higher, but the canned fuels are 93-96.

 

[Maintenance Chief]

Just updating on the saw! I haven’t got to use it much. Been a lot of maintenance days and little prunings around the holidays. I’m finding I like a torquey saw and this thing powers through the wood with a 7 pin sprocket. After the holidays we have a big removal job. 14 white oaks on one property so she will be getting lots of play time then! I do have a question though. All of our saws are stihl, the only ported saws I have is the 500i and my 395xp. What octane gas should I use? Running 32:1 dominator in the ported saws and 40:1 red armor in the regular saws. I was always under the impression that higher octane is better but recently I’m learning that too high of an octane can actually cause a loss of power. Been running 91 octane. Should I go down in octane? Thank you all and happy new year!

91 octane is not high, 110 is on the high side.
Its perspective, when I first started driving 98 was at the pump .

 

[TINYHULK]

What do y’all think about this?

the one justification was the octane in the cans were too high for those machines.

 

[Maintenance Chief]

What do y’all think about this?

the one justification was the octane in the cans were too high for those machines.

Yeah I'm subbed to her channel but I don't agree with everything that she thinks.

 

[TINYHULK]

Yeah. I’m new to all this but it seems to vary some based on what I have learned from all of you. This and some other reads is what got me wondering about octane in these saws and if I was losing power from running it too high

 

[Maintenance Chief]

Really anything ethanol free will do as you base.

 

[TINYHULK]

We don’t get ethanol free fuel around here

 

[huskihl]

We don’t get ethanol free fuel around here

If you can’t get ethanol free, I’d use the freshest available

 

[Shane¹]

We don’t get ethanol free fuel around here

I can't easily get ethanol free either and I would say keep it fresh and I would go higher octane. May loose a tiny bit of performance but should keep motor cooler which I think is more important

 

[mrxlh]

What do y’all think about this?

the one justification was the octane in the cans were too high for those machines.

Tru fuel 50:1 was lean tested, and it performed very well. I wouldn’t hesitate to run it in anything I own.

 

[Flying_Dutchman]

I run e free 90 in my personal saws, 87 e10 in all the tree service saws.

 

[KS Plainsman]

Tru fuel 40:1 was lean tested, and it performed very well. I wouldn’t hesitate to run it in anything I own.

It's all I run in all my 2 stroke OPE, except my 394 and 3120. Does good for me.

 

[TINYHULK]

Any point where too low of an octane is a concern? I’ve heard that some/most/all 2 stroke mixes have things in them like fuel stabilizer for ethanol or octane booster. Any truth to that?

 

[mrxlh]

Any point where too low of an octane is a concern? I’ve heard that some/most/all 2 stroke mixes have things in them like fuel stabilizer for ethanol or octane booster. Any truth to that?

Saws are low compression, octane level on all but super stale fuel won’t be an issue.

 

[Dieselshawn]

This has been a good thread to read. Read it from start to this point.

Moparmyway, good job on bringing the saw back to life! Sounds good in the video.

Tinyhulk and Sierra-rider, nice looking saws! I like the colour scheme on both.

At the beginning, when I saw the piston, at first look, the oil didn’t look good on the skirt. This would explain the carbon build up. Carbon is basically like diamonds scratching the piston.

Some oils can lubricate the bottom end fine, but don’t burn right at certain temperatures that the saw operates at causing carbon to build up. Then pieces break off, scratching the piston.

Tinyhulk, hopefully your piston and cylinder looks like this for a long time. Like Moparmyway said in a earlier post, he was able to easily wipe up his exhaust port.

this is a Stihl 660 at 32:1 with around 30 or more tanks of gas through.