The exhaust port was only 59% of bore diameter
I think I would say it was a four corner siezure.
I think I would say it was a four corner siezure. Run hard with no warm up. Likely the timing advance would have been a factor. As much as I have seen timing advances are bandaids for poor portjobs, esp ones where the exhaust port got a little too high.
Looks like you might be able to save it if you drop the jug down a little.
That crossed my mind Transfers are too high for a pipe though, at least from what I've read.
I worked on a saw done by the same builder (Jonsered 2186). The exhaust port was tall and the transfers were too high. Blowdown was about 18 degrees. I wasn't able to make it much of a runner without a new jug. Exhaust duration was around 185°. The porting work looked identical to the 3120 jug pictured.
Makes sense to me. Thanks for your input Brian. Keep that in mind you guys like like to rev the daylights out of your saws as soon as they fire up cold. I see it done all the time, and most get away with it. But what's a few seconds if it cost you your saw?
I do it all the time.
Most of the irregularities in the cylinder wall honed out. It was only a couple quick hones in both directions. I use the 320 grit hones from Baileys. I'm hoping for the best.
But a 3120?
But a 3120?
Damn, that hone sure does work well.
dog,
don't be silly..
you port a saw because it makes it lighter !!!!!!!
really, think about it !!!
My 084 was a total disappointment stock. So yes, even the big boys
It's a stihl...hahahaha... just kidding!
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