Jonsered 2063 to 2071 bigbore

[Joakim S]

New member on the Forum here.

I'm rebuilding a Jonsered 2063 to a 2071 bigbore. Ported. The saw is apart, and cleaned, and I started with the transfers, while I'm waiting for the crankhouse gasket. I haven't measured the squish or the numbers yet. This is my second saw I'm porting.

 

[Joakim S]

Some more pics

 

[Bjorn]

Hello. Is it going to be a race Saw or a torque monster. And what fuel are you going to use, alky, nitro, or gasoline? Regular muffler or Tuned pipe?

 

[Joakim S]

Hello. Is it going to be a race Saw or a torque monster. And what fuel are you going to use, alky, nitro, or gasoline? Regular muffler or Tuned pipe?

Hi Bjorn

I think they call it "worksaw". .
Probably I will be using Aspen 2. The muffler will have some modifications, but not a big pipe.
Maybe I drill a hole, and put one of these "roofs" on the top.

 

[Joakim S]

 

[Dub11]

Welcome and nice thread!

 

[Joakim S]

Hi again

Now I've finally measured my numbers on the new cylinder. Maybe someone could help me which numbers I should aim on, when porting. Like I said before I would like to have a reliable work saw.

Hyway cylinder 2071 big bore (2171)

Squish 0.65mm. 25,6 thousands. No gasket Outtakeports opens 101 degrees
Intakeport opens 72 degrees
Transfers opens 130 degrees

Joakim

 

[Bjorn]

Hello, Are you 100% sure, that the primary and secundary Transfers open att the same Time?

 

[Joakim S]

Hi

Nope, I'm not. I will try to check that out in the evening.

Thanks

 

[Joakim S]

Hello, Are you 100% sure, that the primary and secundary Transfers open att the same Time?

It looks like they opens at the same time, Bjorn.

 

[Bjorn]

Yes, you are right. Time to calculate some timing Numbers.