All I can say is wow at that kind of compression and no machine work. Was that just after assembly or after some run time. Assembly lube can make a big difference.
Woods Porting (UK)
- Thread starter Geal
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scotclayshooter
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Thats after 10 or so tanks.
Been thinking about a 0.012" pop up and do away with the base gasket.
What a pig it was to start the very first time! Seems i was a little confused that the switch went the opposite way to the Makita GRRRRR It was well flooded lol
A buddy had a go cutting down an Elm with it i didnt think i was going to get it back. looked really impressive with someone else running it.
Been thinking about a 0.012" pop up and do away with the base gasket.
What a pig it was to start the very first time! Seems i was a little confused that the switch went the opposite way to the Makita GRRRRR It was well flooded lol
A buddy had a go cutting down an Elm with it i didnt think i was going to get it back. looked really impressive with someone else running it.
The Lorax
ArboristSite Guru
Thanks Tommy, You have exactly the same setup with the Elasto-start handle as me! Great minds think alike and all that.
scotclayshooter
Addicted to ArboristSite
It needs all the help it can get lol
I think i have MS361 elasto starts on neary everything now!
I dropped the jug .5mm so i raised the exhaust the .5mm + another .5mm so 1mm total. widend and squared the exhaust and inlet a fair bit but left a 1.5mm seal on either side of the piston on the exhaust side.
I blended the bottom of the transfers to smooth the flow but not too much as to increase the crankcase volume.
And widened the transfers 2mm towards the intake.
I tried to raise them back up .5mm but that was not really possible with my tool.
I opened the windows in the piston and smoothed them out.
New ring fitted
Squish is mostly 0.020" but theres a tiny minute miniscule bit of solder that measures 0.011"!!!!!
TW guided me through it.
It cuts well with a 8 pin and a 15" bar but im going to try the 7 pin and my new 16" bar soon maybe with square chain
this info is great but im not sure on a few things e.g how do i drop the jug and how do i adjust the squish, thanks
scotclayshooter
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this info is great but im not sure on a few things e.g how do i drop the jug and how do i adjust the squish, thanks
Were talking about using a thinner base gasket to no base gasket or in some cases you need to machine the bottom of the cylinder slightly thinner to get the squish you desire.
You know how to measure the squish with a couple of bits of solder through the plug hole pull the engine over a few times and measure it dont you?
to be ohnest with you i ahve heard alot of things about squish but dont know exactly how to measure it? and what would be the best squish to have, would be great if you could answer these for me,thanks.
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scotclayshooter
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to be ohnest with you i ahve heard alot of things about squish but dont know exactly how to measure it? and what would be the best squish to have, would be great if you could answer these for me,thanks.
Take 2 bits of thinish solder 1mm maybe, take the plug out and pull the rope until the piston is fairly near the top of the cylinder.
bend one bit of solder so you can reach the cylinder wall at the rear and the other so it hits the front wall.
Pull on the starter again slowly and it will squeeze the solder then the engine will turn completly over, I let it turn a few times then take the solder out and measure it.
You can repeat this for the 3 an 9 oclock positions.
The rule of thumb seems to be 0.020" or .5mm but ive heard 0.015" on ms260 size saws and bigger gaps on bigger saws
ok thanks for that iv measure it later on my Ms250 and 660 but cant on the 361 its in bits at the moment.
scotclayshooter
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Measure the 250 if you want but theres nothing you can do about it!
That type of engine is not adjustable, Its a clamshell so to sdjust it you would need to weld metal on to the pop of the piston.
The chances are you would warp the piston and the increased weight aint going to help.
