Fist time porting question (372)

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Put a new bar an chain on it, what a difference a new chain makes. The oiler was working, the bar had some gunk in the oil hole. I'm suprised how well it runs. WOT rpm is at 13,600. I'm out of wood, so that's it for tuning until I find some more.

 
I think I understand why so many on this forum have ported saws. I know this isn't an awesome saw but compared to my other 371 & 372 saws this one feels the best. My other ones are all set around 13,000 rpm and I'm thinking I like the higher rpm.
 
Well I tried it out this morning. It ended up having a disappointing 140lbs compression but i guess that to be expected with the high squish. It should rise a little as it brakes in. It's running around 14,200 rpm and four stroking a little, it's hard to hear in the video but it is. My bar quit getting oil so I've got to see whats up with that. I have a new bar and chain so I'm going to put that on, turn down the rpm to around 13,500 and go from there. I also got to ind some more wood]
Wow I am surprised the squish is at 34 thou with the cylinder slammed. That's the flat top 372 piston you were saying?
So it would give you close to .050" with a gasket?
Was that 372 OEM piston and rings then on the clone saw? Older rings?
Cold test?

The last one I did for me had a window OEM 266 and OEM cylinder
I use next to no 2 stroke oil putting saws together. Buddy lightly ported a 52 mm at the same time with stock piston.
Only time I ever checked a saw with a comp tester.
The 50mm single ring was 150 and 170 was the 52mm. Both slammed.
The comp always seemed weak on the cord but impressed in the wood.
I prefured it over the BB.
I wanted to try it with the chamber cut.
Buddy had some very light AM 266 on hand so I cut the chamber but it wouldn't heat transfer I found out when speed falling a group of 3 1/2 ft cottowoods. (no on speed) The definition of melt down is when 50cc becomes ml
(mililitres) thats when I realized I was stupid. Curiosity has killed more than the cat.

The BB was very strong in the end. I used it on the coast for a month production falling. Made short work of an 8ft Spruce. Make sure the plugs don't come loose, the threads are not very forgiving.

Your saw should come up in comp. It will get a carbon build up on the top of the piston and tighten the squish.
I have had saws I have pulled apart because the squish was too tight after a few weeks. It went from a throatty sound to a ping. Think it was a 272 dome. It wasn't burning properly for some reason. Just my eyeballs and throat.
 
Wow I am surprised the squish is at 34 thou with the cylinder slammed. That's the flat top 372 piston you were saying?
So it would give you close to .050" with a gasket?
Was that 372 OEM piston and rings then on the clone saw? Older rings?
Cold test?

The last one I did for me had a window OEM 266 and OEM cylinder
I use next to no 2 stroke oil putting saws together. Buddy lightly ported a 52 mm at the same time with stock piston.
Only time I ever checked a saw with a comp tester.
The 50mm single ring was 150 and 170 was the 52mm. Both slammed.
The comp always seemed weak on the cord but impressed in the wood.
I prefured it over the BB.
I wanted to try it with the chamber cut.
Buddy had some very light AM 266 on hand so I cut the chamber but it wouldn't heat transfer I found out when speed falling a group of 3 1/2 ft cottowoods. (no on speed) The definition of melt down is when 50cc becomes ml
(mililitres) thats when I realized I was stupid. Curiosity has killed more than the cat.

The BB was very strong in the end. I used it on the coast for a month production falling. Made short work of an 8ft Spruce. Make sure the plugs don't come loose, the threads are not very forgiving.

Your saw should come up in comp. It will get a carbon build up on the top of the piston and tighten the squish.
I have had saws I have pulled apart because the squish was too tight after a few weeks. It went from a throatty sound to a ping. Think it was a 272 dome. It wasn't burning properly for some reason. Just my eyeballs and throat.
It's a two ring Onepro/Chinese 372 piston with the rings that came with it. The cylinder is also Chinese. I've used a few of the Chinese cylinders and everyone I've ever use had a high squish. For someone like me who only cuts 3-4 cord of firewood a year it should last a good long while and if it don't I'm not out much.
 
So, I put the cylinder and 372 piston on the clone saw without the gasket. I don't have high hopes for it, squish was .034-.035, but we'll see how it does. I have another Farmertec cylinder and a couple of crankcases so I'll keep trying until I get it right. Thanks again for the tips I'll post how it turns out.
Don't hack the bottom lip this time.
What size pop -up was that? 30mm, .030" ? I have never use an AM cylinder for that build either. I noticed you are using and x-torque carb too.
That's a big carb. Apparently bigger than the 385. When are you going to do it?
 
Don't hack the bottom lip this time.
What size pop -up was that? 30mm, .030" ? I have never use an AM cylinder for that build either. I noticed you are using and x-torque carb too.
That's a big carb. Apparently bigger than the 385. When are you going to do it?
Its around .020 pop up I don't remember exactly. Next time I won't cut the flange and try and get some better timing numbers. The 1st carbs were aftermarket 385 and the last one I tried was an OEM 372 HD12 Walbro, I put the Walbro on the clone saw.
 
Don't hack the bottom lip this time.
What size pop -up was that? 30mm, .030" ? I have never use an AM cylinder for that build either. I noticed you are using and x-torque carb too.
That's a big carb. Apparently bigger than the 385. When are you going to do it?
I told you wrong on the clone saw carb. I left the Chinese one the came with the saw on it and put the Walbro on the first saw with the black starter cover.
 
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