Ms170 won't start just backfires, we modified the muffler and now it won't start. This is my buddies and I just did the same to mine first and it worked great. It has spark 130psi gas. It gets flooded right away we even put my carb on it and same thing. Magneto gap is about a playing card but I did notice that it did make contact and gouged it a little bit. It's a new saw. Any suggestions thanks.
Ms170 won't start just backfires mod muffler
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Try a new plug first, that might be all.
Then check your flywheel key.
Then check your flywheel key.
LegDeLimber
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"Made contact and gouged a bit"
I'm in agreement on checking the flywheel key.
I'm in agreement on checking the flywheel key.
cedarshark
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Muffler modded. Dealer prob wont warrantee it.
joeblacky
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99% chance it being a flywheel key. If it's sheared, remove both parts, the bit on the crank may need tapping out with a small punch from one side, trying to rotate it round it's half moon shape. Then check the crank and inside of the flywheel arbor for scoring.
If I get a saw that's sheared a key, I always cover the taper of the crank with valve lapping compound, stick the flywheel back on and spin it for a minute or two by hand. This will remove any scoring on both the flywheel and the crank, and ensure a good tight fit on the taper when the flywheel has been cleaned and re-fitted
If I get a saw that's sheared a key, I always cover the taper of the crank with valve lapping compound, stick the flywheel back on and spin it for a minute or two by hand. This will remove any scoring on both the flywheel and the crank, and ensure a good tight fit on the taper when the flywheel has been cleaned and re-fitted
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How could you do this with a ms170?
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Just torque the flywheel nut correctly when installing the new flywheel.
joeblacky
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I'm not sure I follow?
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The key is part of the flywheel.
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joeblacky
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Ah i see, that's Not a design I'm overly fond of! In that case yes you're right, fresh flywheel is in order. Seems such a shame!
Alternatively if you didn't want to buy a new flywheel, you could clean up the taper as best you can, apply a little toothpaste and torque the flywheel back down in the correct position. I've had great success with this and the tip came from a friend who had a trials bike shop. The small amount of toothpaste gives some extra bite between the flywheel and crank, and does not set like a glue would, allowing easy removal. I've also had success doing this with fine valve lapping compound
Alternatively if you didn't want to buy a new flywheel, you could clean up the taper as best you can, apply a little toothpaste and torque the flywheel back down in the correct position. I've had great success with this and the tip came from a friend who had a trials bike shop. The small amount of toothpaste gives some extra bite between the flywheel and crank, and does not set like a glue would, allowing easy removal. I've also had success doing this with fine valve lapping compound
