Stihl 170 mods

[J D]

So why do you think the lubrication is ok on the bearings but not the piston ? I do get the theory about a higher viscosity fuel mix and it being leaner with the same jetting

It's the heat that's the problem for the piston, especially on the exhaust side

 

[C George]

The oil im running can handle it

 

[anlrolfe]

IMHO, the #1 performance mod for an MS170 or MS180 is to install a side adjust chain tensioner from an MS250.
This quick part swap will, hands down, save you SO MUCH time and aggravation in the field.
I'd bend out the exhaust ports out and let the rest of it alone. The second the carb give you trouble, upgrade. The filter system on this is designed like a happy meal toy and if anything is out of alignment you're sucking dust. On one of mine the brake handle lever was bumping the top cover and slightly lifting it out of place compromising the filter alignment. DREMEL to the rescue. This could have been partly due to FleeBay ChiCom engine 180 upgrade. Who knows if the dimensions where true to OEM spec.
I run a toasted 170 to 180 conversion with AM wt215 carb. It's hard to hear the 1st burp and tuning in the cut is a must. I think this is a byproduct of the big carb.

 

[J D]

The oil im running can handle it

Bend over MS 170, this is gonna get HOT! but don't worry... the lube can handle it

 

[GenXer]

I did a carb swap and muffler on my 017, works great now.

 

[rupedoggy]

Bend over MS 170, this is gonna get HOT! but don't worry... the lube can handle it

Hey JD do you always comment on things you have little knowledge about? That is a rather crude comment. Well anyway this is the internet and easy enough to ignore your input.

 

[J D]

Hey JD do you always comment on things you have little knowledge about? That is a rather crude comment. Well anyway this is the internet and easy enough to ignore your input.

It was a joke... & yes, a fairly crude one. I didn't think it was the kind of thing that would upset anyone around here, my apologies if it has.
I do stand by the point that you can't lubricate away the issues lean running will create.
I'm also genuinely concerned that the OP has seriously leaned his saws out & this will likely result in their premature failure.
As you say, this is the internet & everyone is free to assess what they read & ignore information appropriately. Maybe we should all do so more often LoL

 

[rupedoggy]

I want you to try to blow up a saw. (melt the piston) by leaning it out with additional oil. Start at 32;1 then 16;1 then 8;1. run the saws as hard as you can and see if they fail. I have challenged several people to this and NO ONE has blown up a saw. I even tried it myself. You sir are deluding yourself. I don't care if you do, but putting it on here like you are the know all and be all kind of bothers me.

 

[Woodslasher]

I want you to try to blow up a saw. (melt the piston) by leaning it out with additional oil. Start at 32;1 then 16;1 then 8;1. run the saws as hard as you can and see if they fail. I have challenged several people to this and NO ONE has blown up a saw. I even tried it myself. You sir are deluding yourself. I don't care if you do, but putting it on here like you are the know all and be all kind of bothers me.

I think JD is trying to say that the guy's saw is running lean and he needs to richen up the mixture, and adding extra oil to the mix is not the way to deal with a saw that's running too lean.

 

[J D]

I think JD is trying to say that the guy's saw is running lean and he needs to richen up the mixture, and adding extra oil to the mix is not the way to deal with a saw that's running too lean.

Yes, this ^^^... it's not the extra oil, it's the extra lean that I suspect is going to be an issue