Stihl MS194t Problems...

[Bludenz]

Hello All,
I posted a while back requesting a workshop manual for a Stihl MS194t. Well, after a lot of mucking around with it, I haven't been able to get it to run. I've cleaned the carby twice (taken off covers, gaskets, etc...). Currently, the carby is completely apart, and I am reassembling it in the next few hours.

However, my problem is that even after the carby was cleaned previously, the saw will "start" after a few pulls, but immediately goes into a very high idle and then dies. No throttle given, nothing. What could the problem be? Is it possible that the spark plug is causing it? I've nicked the spark plug from another saw, same specs as the Stihl ms194t so I don't see how it could be an issue. Is it worth paying the $250 AUD to get a new carby from Stihl, or am I good with a $30 AUD carby and spark plug set off ebay?

The piston and cylinder look ok, no obvious signs of damage, piston/cylinder scarring, etc... I've tried adjusting the idle knobs (correctly, as per the manual), but to no avail. Would love to get this saw running for the summer to trim up a few trees!

Thank you in advance,
B.

 

[altatim]

Vacuum and pressure test the saw first and then see whats up. Could be many things but racing idle is normally caused by either an air leak or fuel starvation (i.e. lean condition both ways)

 

[coffeebrk]

Did you put a rebuild kit in the carb?

 

[ZeroJunk]

Not sure you need to test for an air leak. Just find it.
Check the intake manifold closely for a crack.

 

[lone wolf]

Not sure you need to test for an air leak. Just find it.
Check the intake manifold closely for a crack.

Sounds like a big air leak.

 

[Bludenz]

Thank you all for your responses. I'll check for an airleak today.

To answer your question @coffeebrk I did not put a rebuild kit in the carb. I've only tore it down to bare bones, cleaned it with an ultrasonic cleaner and reassembled.

 

[ZeroJunk]

Sounds like a big air leak.

I may not have been thinking right. If he has the saw in the start position it would normally go to a high idle. Choke is independent lever on the side of the carb housing
So, if it goes to high idle and dies it may just be running out of fuel.

 

[Bludenz]

I may not have been thinking right. If he has the saw in the start position it would normally go to a high idle. Choke is independent lever on the side of the carb housing
So, if it goes to high idle and dies it may just be running out of fuel.

Could this be the case of a faulty carburetor? I didn't get around to testing the air leak yesterday but will later today. Will update this thread with what I find. If i remember correctly, last time I tested it, if i held the throttle (as it started) it would stay running, however when i let of the throttle, and it got into the lower RPMs, it died.

Thank you again for your help!

 

[ZeroJunk]

Could this be the case of a faulty carburetor? I didn't get around to testing the air leak yesterday but will later today. Will update this thread with what I find. If i remember correctly, last time I tested it, if i held the throttle (as it started) it would stay running, however when i let of the throttle, and it got into the lower RPMs, it died.

Thank you again for your help!

Could be. Bad fuel line. Stopped up filter. Stopped up impulse. Not turning the choke off. etc.

 

[Bludenz]

Oh well... After getting home from work I went out to the shed and got out the 194t. I did some testing with my air leak tester and found that the leak was near the bottom pan. There was some play in the crank so I thought that the screws had loosened out of the bottom pan. Well, after about an hour of disassembly, and organising parts, the engine was out.

The final problem? A cracked lower engine pan... Off to ebay and my local Stihl dealer tomorrow to get a quote for this - opinions on buying used lower engine pans?

 

[lone wolf]

Oh well... After getting home from work I went out to the shed and got out the 194t. I did some testing with my air leak tester and found that the leak was near the bottom pan. There was some play in the crank so I thought that the screws had loosened out of the bottom pan. Well, after about an hour of disassembly, and organising parts, the engine was out.

The final problem? A cracked lower engine pan... Off to ebay and my local Stihl dealer tomorrow to get a quote for this - opinions on buying used lower engine pans?

You should be able to buy a complete saw on Ebay with scored top end cheap. Take a look.

 

[Bludenz]

You should be able to buy a complete saw on Ebay with scored top end cheap. Take a look.

Prices seem to start around 100 usd just for a saw, which is not all that bad. Shipping to Australia then adds an extra 130ish USD, if not more. For context, I paid 150 AUD (100usd) for this saw in it's current condition from an arborist in my local area. Sold as is "won't start" - I figured that one out now...

I think I will be better off buying a Crankcase Pan by its self, which only totals around 30 usd with shipping to Australia. However I also noticed that because of the crack in the pan, it allowed play in the crank. The play was enough for it to cause the flywheel magnet to touch the ignition coil. There are some scuff marks on the magnet of the flywheel, however, the ignition coil looks to be in okay condition. Is there any cause for concern here?

 

[Bludenz]

Called my local Stihl dealer who quoted me 25 aud (17usd) for a new lower engine pan. Will be popping in later this week and hopefully will repair the saw this weekend if everything goes to plan. Hopefully the crank doesn't need new bearings or new oil seals...

First time for me where local dealer is cheaper then ebay - hopefully they will have the part in stock so I don't have to wait for it either!

 

[singinwoodwackr]

I may not have been thinking right. If he has the saw in the start position it would normally go to a high idle. Choke is independent lever on the side of the carb housing
So, if it goes to high idle and dies it may just be running out of fuel.

I have a 262 that does that. done multiple vac/press tests, all good. It actually acts like a saw does when the tank gets empty. carb rebuilt twice, no joy. new fuel line, filter, checked impulse... Put it aside, waiting for inspiration It ran great for a whole tree...week later, this crap. sigh..

 

[singinwoodwackr]

Prices seem to start around 100 usd just for a saw, which is not all that bad. Shipping to Australia then adds an extra 130ish USD, if not more. For context, I paid 150 AUD (100usd) for this saw in it's current condition from an arborist in my local area. Sold as is "won't start" - I figured that one out now...

I think I will be better off buying a Crankcase Pan by its self, which only totals around 30 usd with shipping to Australia. However I also noticed that because of the crack in the pan, it allowed play in the crank. The play was enough for it to cause the flywheel magnet to touch the ignition coil. There are some scuff marks on the magnet of the flywheel, however, the ignition coil looks to be in okay condition. Is there any cause for concern here?

they should be ok.

 

[Bludenz]

Oh well. Went to my local Stihl dealer to pick up some parts - turns out they don't have the engine pan in stock. However, the guy gave me a second hand one for free! Part number was 1137 021 2503 on the pan he gave me. Got home, took of the old, cracked one and the new one doesn't fit...

There is a clear difference in size, and the distance between the screw holes. Also, the pan with the PN ending in 03 has "dividers" or "fins" on the inside with the number 3 stamped inside of the pan. The pan with the PN ending in 00 has no dividers or fins of any sort, and has the number 2 stamped into the inside. Is the engine pan with the part number 1137 021 2500 discontinued or outdated?

Unfortunately my local stihl dealer is now closed, so I'll be back Monday to figure things out. Might have to end up paying a little more and getting one of
ebay.

EDIT: Turns out that this might be a MS192t chainsaw - Can't verify serial number as the Stihl Serial Number lookup tool isn't working at the moment. The badge on the side of the chainsaw says MS194t, however it has MS192t internals...

 

[singinwoodwackr]

Oh well. Went to my local Stihl dealer to pick up some parts - turns out they don't have the engine pan in stock. However, the guy gave me a second hand one for free! Part number was 1137 021 2503 on the pan he gave me. Got home, took of the old, cracked one and the new one doesn't fit...

There is a clear difference in size, and the distance between the screw holes. Also, the pan with the PN ending in 03 has "dividers" or "fins" on the inside with the number 3 stamped inside of the pan. The pan with the PN ending in 00 has no dividers or fins of any sort, and has the number 2 stamped into the inside. Is the engine pan with the part number 1137 021 2500 discontinued or outdated?

Unfortunately my local stihl dealer is now closed, so I'll be back Monday to figure things out. Might have to end up paying a little more and getting one of
ebay.

EDIT: Turns out that this might be a MS192t chainsaw - Can't verify serial number as the Stihl Serial Number lookup tool isn't working at the moment. The badge on the side of the chainsaw says MS194t, however it has MS192t internals...

Post in the stihl SN look up thread.
Odd that a 193/4 pan won't fit a 192. Yes, motors are different but the pans shouldn't be.

 

[Bludenz]

The serial number is a little worn on the saw so I'll try to decipher it first and then i'll post it - thanks for the advice.

The pans are completely different. As mentioned above, not only the holes have a larger distance between them, but overall the pan is larger. The 193/4 pan also has the fins/dividers in the inside while the 192 one doesn't. I'll go back to my local stihl dealer and try get this figured out...Is it possible that the guy I bought the saw from accidentally put a 194 starter cover on the side instead of a 192? They look pretty similar - same amount of holes, etc... Only difference I can see is that the 194 cover has a black "tab" under the primer bulb, while the 192 does not.

What are the differentiating features between the Stihl ms192/194 - apart from the black tab on the starter cover?

 

[lone wolf]

Series 1137

• Stihl MS 192, 192 T | 2005 – 2014 – MS 192T review
• Stihl MS 193, 193 T | 2014 – 2020
• Stihl MS 194T | 2020 – current

 

[Bludenz]

Series 1137

• Stihl MS 192, 192 T | 2005 – 2014 – MS 192T review
• Stihl MS 193, 193 T | 2014 – 2020
• Stihl MS 194T | 2020 – current

Ah, so the saws are just the newer models of the previous ones? It seems to me that the differences are mainly the engine size (cc, piston etc...).

The intake manifold that was on the saw, as well as the body points to it being a MS192T, however it has a ms194t side cover on it and I can't manage to decipher the serial number. To me it looks like 3897x0x6x. x is what i can't decipher...