390xp

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
I agree, but if money is tight??

385's can be a real good runner ported, you'd be surprised.

I seen the one that Brad did on You tube and it was Awesome! I hear its day/night.
 
Hey will is right,,,,, those 385's are no punks,,, they mod up very well,,, but if you have to have the 390 then save your money,,, get one and then get it modded,,,, you can always sell the 385 P/C and get about 1/2 of the oem 390 p/c cost back

I might just do that! But I always save my old parts!
Some thing I'v learned while working on cars. If it goes up for sale it goes stock.
 
I would really like to run the two of them stock side by side to really see what the difference is.
There is a reason why I went w/ a 385 vs a 390. I really wish I could find my 09' book w/ the prices in it but if I remember right the 390 was like a $100 more for like a .5hp and was a tad heavier.
Now I wish I got the 390 just because they killed the 385! :mad:
 
Just work over the 385 cylinder. I don't think it's worth it to buy another cylinder and have it ported. A worked over 390 will flat out smoke a stock 394 in wood 25" or so.

The work looks good Will. :msp_thumbup:
 
No way would I replace a good 385 cylinder with a 390. A modded 385 runs awesome!

<iframe width="853" height="480" src="http://www.youtube.com/embed/zx5nWV9Stts?rel=0" frameborder="0" allowfullscreen></iframe>
 
390xp BB kit by Logger4Life

I've been wondering if they'll ever come out with a BB390.

I need a few more odds and ends and I will be attempting this build and I will try and keep everyone posted. I am looking for some cosmetic parts yet such as recoil starter cover, clutch cover, top cover,high top air filter cover,and chain brake system. So if anyone knows where or who might have some of these parts please let me know thanks. Anyway I am over boring and honing a 390 55mm cylinder to 56mm raising the combustion chamber as much as I can and I am going to try and use a 2100 thin ring piston I have 2 of the thin ring OEM pistons and a Golf 2100 56mm x 1.2mm ring piston but I think that they will be to tall from the center line of the wrist pin to the top of the piston. so I will probably have to use a 395 piston which is only .5mm taller from wrist pin center line to the top of the piston. Know here lies the problem with the 395 piston choice I have heard from a very respected saw builder that a 395 OEM pistom will come apart at around 14,000 rpm's so the safe bet is to use a limited coil and the other problem is the case volume but I have to go for now you know X-mas stuff. but I will let everyone know what I find out . And Parrisw nice work keep it up , I am also building a 390xp right now the same way so good luck mine is a hardwood saw.
 
Right on, I have never done a saw build, but alot of saw relate repair's, and maintenance. Pulled my hair out, and had quite a few headache's. Even had to walk away for day's or week's due to frustration. Even had some that the fix was right in front of me, and I was looking to hard.
 
Doesn't matter, he did it in the 4-jaw chuck.

Steve

yes, it was in the 4-jaw chuck, BUT the chuck was clamped onto a plate on the TOP on the cyl, that was attached by FOUR bolts to the CYL BASE...

there-in lies my question...

IF you draw triangulation lines from all the bolt holes, do they intersect the exact center of the bore...


OR, Will, did you spin the top end until there was ZERO noticable out-of-round (if you will) spinning??

thanks! :cheers:


Jay
 
yes, it was in the 4-jaw chuck, BUT the chuck was clamped onto a plate on the TOP on the cyl, that was attached by FOUR bolts to the CYL BASE...

there-in lies my question...

IF you draw triangulation lines from all the bolt holes, do they intersect the exact center of the bore...


OR, Will, did you spin the top end until there was ZERO noticable out-of-round (if you will) spinning??

thanks! :cheers:


Jay

Doesn't matter if the bolts center the cylinder or not. Its in a 4 Jaw, you adjust till you have 0 runout on the bore.
 
Doesn't matter if the bolts center the cylinder or not. Its in a 4 Jaw, you adjust till you have 0 runout on the bore.

Ah...hmm... keep in mind, I have NOT run a lathe before...

so you adjust the jaws till you measure zero runout on the inside of the bore when turning the piece??

got it ;)


:rock:
 
Ah...hmm... keep in mind, I have NOT run a lathe before...

so you adjust the jaws till you measure zero runout on the inside of the bore when turning the piece??

got it ;)


:rock:

Yes.

The back plate isn't perfectly square either. This 4 jaw chuck, each jaw is independent of the others, so you must adjust each one individually, way better to use 4 jaw when machining already made parts like this.
 
Back
Top