Is this okay porting job?

[Carlos motors]

While we are talking and I mentioned oil.. What do you think how much oil matters in this engines? Does more cheap oil equals less expensive oil?

 

[Dserna]

Sorry to interrupt this thread but how do you measure the port width?

 

[Dserna]

The best way is to make a port map and measure it on the paper after.
https://www.apriliaforum.com/forums/showthread.php?261894-How-to-make-a-port-map

Thank you for your reply and time!!

 

[Carlos motors]

Just remember to not go too much, it just needs to be a smooth transition for the rings.
That's great to hear, it's their fault for not properly packaging their items.

Oil is a big deal on these old motor. Meaning using oil and proper amounts of it. The brand/type is subjective and up to much debate.
I recommend 16:1 for break in, 20:1-32:1 after on chrome cylinders 24:1-40:1 for sleeved.
As far as type and quality. Do research, check the ingredients using the material data safety sheet that a reputable oil company should have.

Personally I like castor based 2 stroke oil.

Hi Akutey I made my bas gasket fit the cylinder and when I put it on engine this is how it looks. Should I port the engine also to match this or it isnt worth it?

 

[Carlos motors]

It is very worth making sure your gaskets match and do not overhang into the engine. It will cause bad disturbance in flow and reduce overall power.

A big improvement can be gained from matching the case and transfers. The engine will have to be split to ensure no contamination as you will be dremeling a bunch of the case metal away.

Also I just installed cylinder how does it looks?
Should I trim cylinder top? And how much?
Intake picture is at top and exhaust at the bottom

 

[Carlos motors]

So I need to tri

Sand the cylinder head exactly 1mm. You must use figure 8 pattern sanding on a piece of flat glass with sandpaper taped down firmly.
Intake can be trimmed to match the port at TDC, don't do more then 2mm or you will half to fill the floor with JB Weld to compensate the duration.

So I need to trim head not cylinder top?
And by trimming intake what do you mean? Should I make piston skirts or?

 

[Carlos motors]

Sorry I meant top of cylinder. Trying to cylinder deck here.

Yes the piston skirts can be trimmed or smoothed or the roof can be filled instead. Overhang create's turbulence.

Here in croatia we dont have jb weld so I will just make 2mm skirt. And should intake timing be good with that or?..

 

[Carlos motors]

And how big is risk/reward ratio. Will it matter that I make this skirt or is better not to? If you understand what I'm saying I really dont wont to loose bottom end power so I'm interrested if there is difference between 120 and 135 degrees.( also should I make one on each side to prevent disbalance?)

 

[Carlos motors]

It worth it on some well tuned setup's but will lower the duration you have to compress your mixture into the cylinder.
Thats it why I don't recommend it unless you have a tuned expansion chamber or a stuffed crankcase.

Yeah, I think I will skip that part then... Maybe after learning and making (or buying) good expansion chamber I can think of taking everything to next level and maybe reed valve setup and some other stuff but for now I think is enough. I know this question is hard to answer,but how much hp do you think my engine has now? I think stock is around 1.2hp?
I have port matched intake and exhaust( probably will do tranfers also), ported intake and exhaust got better filter and jets, and will do squish gap to ,8mm, and my exhaust isnt perfect like you said but it certanly ads some power. My free guess would be around 3.5.

 

[Carlos motors]

Stock was dyno'd at 1.8HP.
Check out the channel on youtube "2 stroke stuffing" There you can learn alot.

Yes I have watched all his videos about mb several times. Too bad he didn't ported cylinder..