Spark Plug Stripped, Repair Stripped

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Ando81

Ando81

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I got the saw back together today and it fired up nicely. I only ran it long enough to generate some combustion temp to hopefully bake the locking compound onto the insert. I was surprised at how new looking everything was inside. All genuine parts including crank seals so I just cleaned them all up and put them back on with some new lube on the seals.


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Okie

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I got the saw back together today and it fired up nicely. I only ran it long enough to generate some combustion temp to hopefully bake the locking compound onto the insert. I was surprised at how new looking everything was inside. All genuine parts including crank seals so I just cleaned them all up and put them back on with some new lube on the seals.


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I have some stuff called Seal Lock Fluid Weld that I apply to valve seats before re-installing and peening and also pinning them in place on the old L head type valve in block engines. It's rated for combustion temps and creates a hard type seal as it's heated and it's rated for combustion temps.
Kinda expensive but little bit goes a long ways and it stores good in a refrigerator. I would not buy just to use on a chainsaw engine that has a stripped out thread for a spark plug sert. Probably be better off to just knuckle down and replace the jug instead of farting around with expermenting on a iffy repair job even for yourself.

Thread lock compounds do not seal better when heated, I use heat to break down and and loosen the permanent type thread lockers.

Here is a link to the Seal Lock for review:

https://www.amazon.com/Seal-Lock-Fluid-Weld-2-oz-Bottle/dp/B00XLW9N9S
 
Ando81

Ando81

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Oct 16, 2018
Messages
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Location
Australia
After some consideration I decided to replace the piston & cylinder on this saw and upgrade it to Ms390 capacity. I lubed everything well during installation and put fresh 25:1 fuel mix in it. I splashed a bit of fuel in the carb to fire it up. It ran ok but didn’t want to idle, I had to adjust the low idle mixture. It seems to be a bit sluggish when cutting but may need card adjustment due to running on different fuel mix. It’s a Chinese piston & cylinder but I installed the Stihl piston pin clips. Should I run it on a couple of tanks of 25:1 before I tune it to rev better just to lubricate everything better during the run in process?
 
Ando81

Ando81

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Messages
247
Location
Australia
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After a bit of running it seems like the compression is improving. It stops very quickly when I turn it off. I’m happier with how it’s running now, however this oil pump outlet seal is very hard and leaks like a sieve. The bar gets some oil but most of it drips out under the saw around the clutch housing. I need to find a tiny o-ring to fix it.
 
Ando81

Ando81

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Oct 16, 2018
Messages
247
Location
Australia
I’ve used the saw and put about half of a tank of fuel through it. It’s got 130 psi compression now, does that sound about right to you people or is it slightly low?
 
Ando81

Ando81

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Joined
Oct 16, 2018
Messages
247
Location
Australia
O-ring has been replaced and it’s all good now. The saw seems ok but I’m still running it slightly rich until the saw has ran in a bit. I can’t really complain with how it’s performing.
 
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