High Quality Chainsaw Bars Husqvarna Toys

Stihl ms270 drives me crazy

chrissalas1

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Hi

I have an ms270 on bench.The saw came to me with the complaint that is not running good.I pressure tested it and found an air leak at the cylinder sealant so opened it and replaced the sealant, the crank seals,the bearing and the piston rings.The piston is in very good shape.I am trying to fire it up with no luck.Replaced the ignition coil with a brand new.Swaped the carb with a known working.Pressure tested again with no leaks.The chainsaw doesn't want to start.Today i did a compression testing and read 122psi but the cylinder and piston is in very good shape.I don't know what else to do.
 

Stem

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impulse line, fuel line, fuel filter, dirty carb?
 

chrissalas1

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New fuel filter.Carb with new repair kit and putted a knowing working carb.Pressure tested the impulse line and the fuel line
 

Stem

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is the fuel good? is it getting fuel into the carb? is the plug good? is the plug wet? I recently bought a new NGK plug that showed very weak spark compared to the old one.
 

chrissalas1

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All the plugs i try come wet.I have the oppama spark tester so i tested and has good spark.The fuel is brand new
 

Stem

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what about the air filter? only other thing I'd try is resetting carb needles to factory spec. other than that idk what to tell ya.
 

Warped5

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Spark test? 270s are known to have wonky coils ...
 

stretch5881

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+1 on the coil. I tried 3 on a 270 before I got a good one. Something about the internal timing of the coil can be fubar. Shows spark, just not at the right time.
 
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chrissalas1

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+1 on the coil. I tried 3 on a 270 before I got a good one. Something about the internal timing of the coil can be fubar. Shows spark, just not at the right time.
You tried 3 that were brand new?
 

popopboat

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Dont know pal what have you already tried but this would be my way.
-Check for fuel carb adjustments/try to start with full throttle
-Remove everything from coil except sparkplug wire (maybe short circuit on stop switch line)
-If it has compression, and not just pufs pufs- should be fine for start atleast.
-Spark timing?
-Plugged exhaust? - start without it?

Even if after all of this it doesnt work... then the only explanation would be that it's cursed. :D
I mean if carb and coil are fine, nothing else could cause a problem.
 

chrissalas1

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Guys i took it to a stihl dealer and today i took it back.The chainsaw now starts and works very very good.I paid 20 euros and when i asked him what was the problem he told me that he cannot tell me.Also told me that it wasn't the ignition nor the carb it was my mistake when i teared down the saw and repaired it something to do with measurements.I cannot find what was the mistake i did.I insisted to tell me but said i cannot tell you.
 

popopboat

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Probably clogged muffler screen then (if it has any),..nothing else crosses my mind.
I guess that 20euros are less worth than your patience and hair :D
 

chrissalas1

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It doesn't have muffler screen.The muffler is clear and and also the exhaust side of the cylinder because every time i remove a cylinder i soda blasting it.The only think that is coming on my mind is the ignition coil gap because i see it very very small after i took it from him.I regaped it like i did before took it to him so tomorrow when is cold i will try to fire it up and see.....
 

chrissalas1

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Guys i tried the first ignition coil and the chainsaw starts fine.I tried 0.35mm gap but shuts off at idle,then tried 0.2mm gap and runs very good.But i saw that the max rpm was about 15000 and i decreased to 13500 due to the stihl manual and guess what.....the chainsaw now doesn't start.I tried the standard setting(low 1 1/4 and high 1 1/8) but it doesn't start,the spark plug is wet.
 

popopboat

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Doesnt even start with full throttle open?
 
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