Jonsered 80 5 Cube Stock Appearing Build

[awol]

For the last year or so I have been spending a few moments now and then working on this project. It has the same bore and stroke as a 281, so if I can get the case shrunk up enough, I think it will be competitive.
Here is the progress so far:

Here is the cylinder laid out for porting, in the beginning stages of grinding. The piston will be from a 372 big bore.



The flywheel had to be cut down to clear the extra material I added to the sides of the trans tunnels. The full circle crank will help shrink up the case volume.


Intake block is built; when the carb bore is the same size as cylinder bore we should have enough flow!

 

[Redfin]

Interesting to watch your work fella. Thanks for posting.

 

[jmssaws]

Kool build. Is it done yet? Lol

 

[295 tramp]

holy smokes what's the carb? looks like one off a 084

 

[Stihl working Hard]

Looking good

 

[lwhaples]

Watching with interest.

 

[Locust Cutter]

Subbed

 

[Magic_Man]

Nice

 

[Redfin]

Moar pleeze.

 

[Toad22t]

 

[Stihlbro]

Nice!

 

[awol]

Thanks for all of the kind words!

I haven't made a lot of progress, but here is a few more pics of the jug. I think I'm gonna bolt it on a stock bottom end that Joey sent me, and take it to the races this weekend.

 

[Stihlbro]

I know of a 066 with with the same carb, it does not supply as much fuel as you would think. It's more of a karting carb for the 5hp Briggs I think. Not saying it won't work. The pump circuit is large. The wet side is limited.


Does the case match up to the finger ports?


Sent from my iPhone using Tapatalk

 

[Stihlbro]

I'll look for the picture and I may still have a video, we went to South Carolina in 2010, there was a Jred 80 there that had a Tillotson Hl on it. If that saw had a operator, there was nothing there that could run with it.


Sent from my iPhone using Tapatalk

 

[Redfin]

Are my eyes decieving or does that have a very narrow squish band?

 

[awol]

I know of a 066 with with the same carb, it does not supply as much fuel as you would think. It's more of a karting carb for the 5hp Briggs I think. Not saying it won't work. The pump circuit is large. The wet side is limited.


Does the case match up to the finger ports?


Sent from my iPhone using Tapatalk

The case didn't match up with the fingers, but it will. The Walbro WB is designed for karts and snowmobiles, but with a selection of needle drills that can be altered. I'll keep a record for future reference.

Are my eyes decieving or does that have a very narrow squish band?

Yes, the squish band is very narrow. That is because the stock piston was domed, we are using a flat top. It is now a nice hemispherical combustion chamber.

 

[Redfin]

Looks like your fingers are at same time as transfers?

 

[Stihlbro]

Here she is!

 

[mdavlee]

Here she is!

I was hoping you had video

 

[Stihlbro]

I'll look for it when I get home. Its one heck of a saw.