jet sizes on modded yam 50hp w/ 70 carbs

[vStrandell]

I have 145's in my 70 carbs mounted on a 40hp and they are on the edge of lean. Finger ported motor.

I think I start out with 150 just to be sure, better rich than lean when breaking in the engine.

What else have done to your engine?

What makes the yammi 40hp tick

[proprider01us]

Lightened flywheel, welded crank, HydroTec high compression head, coated pistons, Fiber reeds with massaged cages, custom tuner pipe....http://youtu.be/uqRzw5Tihu8

I think I start out with 150 just to be sure, better rich than lean when breaking in the engine.

What else have done to your engine?

What makes the yammi 40hp tick

[vStrandell]

Any suggestions regardning compression? Mine has only 115psi even with 1mm lowered head (newer one, center plug). Is it enough to give some Powerr? Or should it be more around 150? The crank rods on this engine does not feel strong at all, very tiny ones, I wonder why yamaha put so small ones in... So is 115 enough? I would prefer lower comressions, since the engine should last long, as I use every day troughout the summer.

[proprider01us]

I get 180psi out of mine, but don't use it daily..

[vStrandell]

First start-up yesterday http://youtu.be/wbrnvExB7oM

[Roflhat]

Porting your engine will also affect your compression

[vStrandell]

Yes, I suppose that is why it has only 115 now, I raised the exhaust port 1.5mm.