Is this okay porting job?

[Carlos motors]

Yes, around their is the best.

That is the maximum it can go before ring wear is big.

Man thanks so much for this informations! I hope I dont bother you too much.. few more questions if you have time.
1)Should I longer intake manifold like 2-3 cm I heard that is good for lower rpms but I wonder does it take also power from higher rpms?
2) How wide should my exhaust be cause Im not sure how much is now, I will measure it, but it should be wider I think so my question is should I make some adapter which goes from wider and than narrows it or should I make completly new pipe? I hope you understood..
3) Should I make piston skirts how does that help?

 

[Carlos motors]

Increasing intake manifold will help fill the cylinder more at lower rpm's. They do take a little off the higher rpm if not compensated somehow.
The stock intakes are around 5cm in length 7.5cm in total from port window to carb.
I found the sweet spot around 12.5cm to 21.0cm with 120* to be the best for acceleration and still doing 50km/h.

Best method is trial and error. Test it now, feel it, use a safe quiet area preferably a trail and watch to test how faster you went.
If you don't like it, disassemble, modify, wash with warm soapy water then dry and reassembl. Test again.
In time you will understand the dynamics of the engine. Your timings are not light but not very aggressive, I try to give you room.

Piston skirt timing opens up intake timing alot more in time then the port does for every mm.
It also lower crankcase compression too by reducing it's time to compress the mixture up into the cylinder.
You need that crankcase compression with a piston port 2 stroke.

I just got my new cylnider but its f***ed up... I posted pictures on other thread.. but probably they will send me another one..
But what I wanted to ask you is that this new cylinder has different dimensions.
Intake on previous 57mm now 57.7

 

[Carlos motors]

Transfers are different shape and lowest height from top of cylinder to top of transfer is 36.1 and as it goes higher it goes to 33
Hope you understood

 

[Carlos motors]

Honestly it still seems fine to run after you give it a wash. (I see contamination)
Just smooth out the edges were its rough and make sure their no further cracks.

Looks like it was dropped by someone at the factory or before shipping. Sad that they still send it out. Bit cheap.
Best way is to make a few extra cylinders for an order and expect losses. But they do exact numbers and hope their perfect instead.

Those are the newer post 2017 cylinders I believe and are made differently.
The different transfer shape is alot better then the old cylinders nasty staircase.
Besides the stair case in the transfer the roof angle were a little excessive for just being primary transfer ports.
All around the transfer geometry and design is more optimal.
Sounds what your describing is an eyebrow, blows most of the initial pressure out to the inlet side of the cylinder to help fill the cylinder in a better manner.

For the most part these cylinders a pre-ported for the same wideband numbers I was trying to give you.

Great
So I should just widen intake amd exhaust like you said?
If I understood corectly you are saying that I could drive with this cylinder? Im not afraid of outside broken but that big chunk where jug goes in to cylinder

 

[Carlos motors]

You think air shouldnt come inside here when its bolted on?

 

[Carlos motors]

It won't with a gasket. Those are kinda like guides for alignment were as some use pegs.
Also could be for the piston skirt to help further prevent piston slap.
I do got a cylinder that I purposely removed those to add a cylinder spacer and had no ill effects.

Makes sense
And I should widen this cylinder on same way like you said me for last one?

 

[Carlos motors]

My exhaust is 23.5mm wide now.
When we talked last time we said max is 28. So maybe 25-26. 1 mm from each side?

 

[Carlos motors]

This is my exhaust
Sort of expansion chamber but I need to put straight pipe in middle for mid range because it is too short..
Do you said this recomondations because you thought I had stock exhaust or its for general?
What happens when exhaust port gets to wide (except ring wear)?

 

[Carlos motors]

That is not stock. I have that pipe, it's good but awfully loud. Only thing is it will not enhance the motor at all with expansion chamber effect.
The chamber is all show. Proportions are all wrong, the cones are not big enough and the header sticks into the cone dampening any waves.


Try this for a read. http://www.amrca.com/tech/tuners.pdf

I red most of the book. Good stuff.
Today I was porting this new cylinder and I didnt managed to do quite a trapesoid shape on intake.. it is more like a square but with rounded edges and chamfer.. Will that be a problem?
Btw bottom line was before like this going to a i point in the middle.

 

[Carlos motors]

Glad to hear. It's a handy book. I don't see a problem. It honestly an amazing looking port job.
Chamfer on the intake only needs to be 2-3mm from the top as thats about how much the intake rings come down in the port.
With the ring ends on the intake side we have to take care in porting the intake roof.

Okay I will chamfer intake roof a bit more. At the end seller sent me full refund because it is their policy or something to not send again.. idk (it was probably damaged in transport, but man spend extra 10 cents or less put it in a cardboard box and everyone's happy), but I dont think I will even need a new cylinder now I fixed this one. I may buy some good castrol oil with this extra cash..