# Stihl MS192T



## edsteeler (Aug 12, 2008)

I have a 192T no matter what I do it will not start.So far I installed new piston and rings,rebuilt two different carbuerators.Compression is 90 psi. It has good spark.I checked all lines nothing looks bad.It's not flooded. I also put in new oil seals. I don't know what to try next. Thanks Ed


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## 30yearTech (Sep 14, 2006)

90 psi is borderline on compression. How did the cylinder look?


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## edsteeler (Aug 12, 2008)

The cyclinder is good. I had a Stihl tech. tell me that 90 is good.I thought 90 was low also.


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## 30yearTech (Sep 14, 2006)

If the cylinder looks good, then perhaps the piston ring is the issue.


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## edsteeler (Aug 12, 2008)

They are new rings and piston.A Stihl tech. has had it now for 3 weeks,talked to him yesterday and is out of ideas.Everything checks good,but it will not start. So I'm thinking paper weight.


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## geogrubb (Jul 28, 2006)

Remove the plug and crank it over 15-20 times, put a teaspoon of fuel in the plug hole and try to start it, full throttle no choke to see if it will try to fire. Have a good one. Geo


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## geogrubb (Jul 28, 2006)

edsteeler said:


> I have a 192T no matter what I do it will not start.So far I installed new piston and rings,rebuilt two different carbuerators.Compression is 90 psi. It has good spark.I checked all lines nothing looks bad.It's not flooded. I also put in new oil seals. I don't know what to try next. Thanks Ed


What was the original problem that caused you to replace the piston and rings. Have a good one. Geo


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## edsteeler (Aug 12, 2008)

Geo.I thought the compression was low at 90.


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## edsteeler (Aug 12, 2008)

Here's where I am now. Stihl tech had it went over everything and decided to try a new coil, even though the old one showed spark, the saw starts but won't keep running,to keep the cost down he gave it back to me,suspecting a air leak.I vacuum tested everything and I can't find a leak.


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## 30yearTech (Sep 14, 2006)

*Ignition Timing...*

Did you or the tech check the flywheel key? 

Ignition timing can cause issues like you describe.


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## edsteeler (Aug 12, 2008)

It's a new flywheel. Thanks


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## geogrubb (Jul 28, 2006)

edsteeler said:


> It's a new flywheel. Thanks


Info from the shop manual for a MS191T:

5.2.1 Ignition Timing
Ignition timing is fixed and is not
adjustable.
Since there is no mechanical wear in
these systems, ignition timing cannot
get out of adjustment. However, an
internal fault in the circuit can alter the
switching point in such a way that a
spark test will still show the system to
be in order although timing is outside
the permissible tolerance. This will
impair engine starting and running
behavior.

Have a good one. Geo


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## edsteeler (Aug 12, 2008)

So did the new coil fix that? Thanks Ed


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## geogrubb (Jul 28, 2006)

edsteeler said:


> So did the new coil fix that? Thanks Ed


I wasn't actually working on a MS191t just looking in the manual to see what might help your problem. Have a good one. Geo


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## edsteeler (Aug 12, 2008)

I can get it to start now and run for a minute on three quarters choke for a minute then quits. The Stihl tech said he put a new carb. on it and it made no difference


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## geogrubb (Jul 28, 2006)

edsteeler said:


> I can get it to start now and run for a minute on three quarters choke for a minute then quits. The Stihl tech said he put a new carb. on it and it made no difference


while it is running spray/dribble some carb/brake partss cleaner behind the carb and along the mating surfaces of the intake, if the engine tempo changes you have an air leak creating a too lean to run situation. Have a good one. Geo


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## edsteeler (Aug 12, 2008)

I loosened the fuel cap alittle and it runs like it should,tighten the cap and it still runs good. Finally something positive.Thanks everyone for your advice.


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## edsteeler (Aug 12, 2008)

I changed the fuel tank vent and it runs like it should.Thanks everyone


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