Porting A 390XP Top End For A Worksaw

[StuntCockWelder]

Awesome Thread!!

 

[Mastermind]

Nice work Moobs.
Thanks for taking the time to share.

That's Mister Moobs to you Jocko.

 

[XP_Slinger]

Takes a lot of time and care to qualify work like this, and I know doing threads like this takes time too, sure appreciate all the effort you put into it! I learned a few things I haven't tried before, really like how you use the card stock, such a simple and effective tool.

Learned that from one of Randy’s old videos. Use it every time I grind.

 

[Terrence Jefferson]

Great thread... i just did my first bit of grinding on a 390 and i wish this was done a week ago but i can always go back in. Thank you for your time.

 

[3browns]

Always nice to know how much thought, planning, and highly detailed work went into the mods on my saws

Thanks for taking the time

Regards

 

[woodfarmer]

That's what happens when these saws run over 13,200 too long. Too much RPM causes a vibration that loosens the jug bolts, and rattles the muffler apart.



The transfer inlet and the stroke I reckon is the most difference Lee.

395 on the left....

View attachment 223366

Why is there windows on the lower of the 390 but the 395 is solid all the way around?

 

[redlight066]

Damn, I thought this was everything needed to port a saw....besides an angle grinder

 

[redlight066]

That’s a unique grind you made on your HSS tool. I’ve been trying to wean myself off of braized carbide tool bits and grind my own HSS. It’s challenging, but when it cuts well, it’s a good sense of accomplishment

 

[huskihl]

Why is there windows on the lower of the 390 but the 395 is solid all the way around?

In the 395, the lower transfers are the big window in the side of the cylinder wall. Mix flows through windows in the piston into the lowers. In the 390, the mix comes up from the crankcase

 

[Cowboy3688]

Thanks Randy for sharin' this! Great stuff!

 

[Cowboy3688]

In the 395, the lower transfers are the big window in the side of the cylinder wall. Mix flows through windows in the piston into the lowers. In the 390, the mix comes up from the crankcase

More btu's?...lol

 

[Brush Ape]

I used to give it all to a hippy chick that made some sort of aroma therapy BS out of it.

Well for us it is aluma therapy. I'm sure the trees aren't gonna like the results though.

 

[Moparmyway]

Damn, I thought this was everything needed to port a saw....besides an angle grinder
View attachment 223404

Dibbs on the pop rocks

 

[huskihl]

More btu's?...lol

 

[Redfin]

I don’t see deep gouges in the intake.....

Or Mickey Mouse ports that are covered by the piston skirt and blue goo.

you sure it’s gunna run?

Blue goo you say?

 

[redlight066]

The pop rocks and cotton candy are Kathy’s. Good luck getting concentrated sugar away from her. Lol.

 

[oldbitz]

Now hang on you're just a forum guy who is just jealous of someones superior work, and you forgot to finish the port off with huge grooves to make the fuel atomise more better gooder for the extra few percent of power.....

On a more serious note nice work mate, some of you guys amaze me with how understated you are when it comes to your work.

 

[Boomhower]

Very nice work sir.

This will be difficult for certain individuals to duplicate needing to know how to read a dial calliper, runout gauges and setup a lathe n stuff.

 

[Lee H]

That's what happens when these saws run over 13,200 too long. Too much RPM causes a vibration that loosens the jug bolts, and rattles the muffler apart.



The transfer inlet and the stroke I reckon is the most difference Lee.

395 on the left....

View attachment 223366

I'm thinkin my future project might be 60mm in a 56mm bore 395. Sounds tasty

 

[Agent Smith]

Blue goo you say?View attachment 223415

Ok i gotta ask. Whats the story behind that cylinder?