Stihl MS192T / MS193T mods, rebuilds, upgrades

[bikemike]

Not a derail. Just a example this is from a galaxy s5 this weekend

 

[Stackowood]

Mike - what program do you use for editing? I'll be moving the videos to my laptop. And thanks, I like the little hot saws.

 

[bikemike]

Mike - what program do you use for editing? I'll be moving the videos to my laptop. And thanks, I like the little hot saws.

My edits were the pause button on my phone. Took the vids that I did get. Post them on youtube then copy link to here. I don't know computers at all. If someone tells me I'm dumb or stupid with a computer, I smile and agree

 

[Stackowood]

Did some tests this morning on 2 brand new MS193T.

#1 saw- 100% stock right out of the box with 2 minutes of run time. No adjustment to mixture screws, and saw is running at 12,200 RPM. When cold it has slow throttle response as expected, but it gets a little better when warm.

#2 saw- also with 2 minutes of run time but has limters trimmed, carb re-adjusted, 3 degrees of timing advance, intake air restrictor opened up, and exhaust deflector modified (see previous pics). Running rich at 12,900 RPM, good throttle response, power improved.

Next step will be putting the modified short block (more intake duration) in saw #2 to see if it's worth the effort.

 

[Stackowood]

Video of saw #1 and #2 in dry 14" cedar, brand new bars and chains.

Forgot to mention - both saws were warmed up prior, so lack of throttle response on #1 isn't very noticeable.

 

[Stackowood]

I'm not much into timed cuts but it looks like saw #2 is roughly 3 seconds faster.

 

[Stackowood]

I was able to run the modified 193T today with the shaved piston skirt and 6 degrees of added intake duration.

It starts easily cold or warm, idle is stable, and there is no spitback to the air cleaner. It sounded like it was hitting a rev limiter at 13,300 so I set it at 13,100, made some cuts, and I'm impressed. Throttle response is immediate and it pulls hard (for a 30cc). Not sure it's worth the effort, but as soon as I can run it against a 200T I'll report back.

 

[bikemike]

For small saws I gotta de rail a moment. I personally think doctors should write a prescription for the 150t and have it modded. It's so light and it's my go to saw now and trim saw. I do removals and trims and run full bar without much of an issue. But if work says all removals for work I bring in the echo 360t workhorse.
Been wanting to check out the new 2511 echo lighter than the stihl 150t. Like I said sorry for the de rail

 

[bikemike]

Video of saw #1 and #2 in dry 14" cedar, brand new bars and chains.

Forgot to mention - both saws were warmed up prior, so lack of throttle response on #1 isn't very noticeable.

Do the same runs after you have more fuel through them. They both sound a bit tight or new

 

[Ketchup]

There's room in a 192t to port it a bit. Not a lot on the intake side, quite a lot on the exhaust.
193t is unknown to me.

 

[bikemike]

I was able to run the modified 193T today with the shaved piston skirt and 6 degrees of added intake duration.

It starts easily cold or warm, idle is stable, and there is no spitback to the air cleaner. It sounded like it was hitting a rev limiter at 13,300 so I set it at 13,100, made some cuts, and I'm impressed. Throttle response is immediate and it pulls hard (for a 30cc). Not sure it's worth the effort, but as soon as I can run it against a 200T I'll report back.

View attachment 80855

Did you get a chance to run the 200 and 193 together?

 

[Stackowood]

I wasn't able to borrow the 200T, so not yet. With summer winding down I think I'll have more time for saw projects.

 

[sixonetonoffun]

Curious why the 191t never gets much love. Mines pretty nice a bit on the heavy side but makes a great old guy saw. Shame it didn't get a closed port cylinder.

 

[huskyboy]

The infamous 200t is quad open port, open ports can run well too

 

[Nutball]

There's room in a 192t to port it a bit. Not a lot on the intake side, quite a lot on the exhaust.
193t is unknown to me.

Have you been in a 193 or 194 yet? Pics? What do they need porting wise?

 

[Ketchup]

Have you been in a 193 or 194 yet? Pics? What do they need porting wise?

I’ve modded a couple of each. The 194 makes considerably more power. I haven’t done full port work on either but looked at it a bit. From memory both have too high of an exhaust and the stupid decomp trough. If I were to go to the trouble of base cutting, getting 0.040” out of the band would help a lot. Probably start at 3 degrees below stock on the exhaust, max out the exhaust width and raise the transfers back to original.

Without having my notes in front of me and a block to set up I’m just spitballing. 70/110/126? With the standard timing advance and muffler mod. Shaving weight off the piston helps considerably on a 192, so I would explore that as well.

 

[Nutball]

Some castor oil and long hot cuts would help take care if the decomp trough. It would be interesting to see if JB Weld would hold up in it, but that's pushing the limit big time. That could end up being a slow release of polishing compound.

110 stock exhaust? Not bad really.

 

[Ketchup]

Some castor oil and long hot cuts would help take care if the decomp trough. It would be interesting to see if JB Weld would hold up in it, but that's pushing the limit big time. That could end up being a slow release of polishing compound.

110 stock exhaust? Not bad really.

IIRC 193 is 108ex stock. It’s the mushiest turd in the pile.
Dropping the jug will help with the trough, but it goes up really high. I cut the base on a 192 and left the trough alone. It made 175psi, which isn’t bad at all at 5600’. The little I’ve done with JB around the exhaust tends to melt and deform. Seems the starter is built for low compression too.

 

[primetimetophandle]

i’m diving into a 192 and a 193 project right now, anyone have a good tip on getting the limiter caps off of the carburetor? thanks everyone