Opinions?

[n_green]

About to send off my head off for a massage.

I'm mainly doing this to improve fuel economy, I've played with the jetting to where I'm super happy with it and it feels crisp and clean however it still only gets 75k to reserve or roughly 1L fuel per 10k's riding.

To start with the bike has all of 55 hours and 1750k's. I've owned it for 20 hours and 550k and since then have run Motul 800 @ 50:1.
Barrel and head looked good, still had a nice sheen of oil. Although piston crown and head tell me its burning rich on the exhaust port side? Is this normal?

The head:

Piston crown:

Barrel:

Exhaust port (looking into cylinder, Piston is at BDC and is above the exhaust port floor:

So quick facts and figures. The bike currently has 140psi after 7 kicks.
It has a single base gasket .5 mm which measures .55mm thick.
Top ring gap is 0.508mm, bottom ring gap is 0.457mm.
At BDC the piston crown is 74.5mm below the top of the cylinder.
The exhaust port floor is 77.5mm below the top of the cylinder.
So stock the piston sits 3mm above the port floor.

The squish band is 1.69mm at the outside (cylinder wall side) and is 2.11 at the inside (bowl side).

 

[n_green]

My Barrel is stamped S3, could it be I have a S3 head?

I know nothing about porting, but these look pretty good?

 

[n_green]

Rear view of my piston:

RHS of piston:

LHS of piston:

Front of piston:

Anyone have any opinions on the piston? It only has 55 hours on it and the rings are hardly worn. Is this a normal amount of blow by? I'd rather not spend $200 on a piston just yet, that eats into my carb mod ^lol

 

[n_green]

With 2 x 0.55mm base gaskets (1.1mm stack) the piston still sits slightly above the exhaust port floor, but only just. (Crown is 75.9mm below top of cylinder, so 1.6mm above port floor)

With 2 x 0.55mm and 1 x 0.3mm base gaskets (1.4mm stack) the piston is flush with the exhaust port floor. (Actually its 1.2mm above port floor)
I attempted to measure squish with this stack however there was that much squish it didn't touch my 2.3mm solder at all

Wondering though if I'm better off just using the 1.1mm stack, would having 3 x gaskets just increase my chances of gasket failure, along with costing more each top end? Will the piston being that extra .3mm lower make that much difference?

 

[gasmonkey]

My opinion;all looks good and normal burn paterns.I'd put another 50 on that piston and rings easy.I wouldn't get too hung up on gasget stack dimensions etc.There's plenty of surface area there to accomadate a number of gasgets.Pick a number and stick with it.
It's the massaging of the head will give you the most notible gains-squish,cr ratio.
No doubt pastor Jake will add his sermon about this subject.

 

[Jakobi]

..posted few cents here and there on the other forum


Gasmonkey summed it up pretty well though