Hi,

1.) What is the factory setting? Can using EVO4 setting?
2.) The idle and everything are not stable after run-in. Is it not run-in enough?

So no one knows?
Shd I sell it?
Any equvilent engine I can go for?

If you provide the information below, maybe someone can offer some suggestions:

How did you break-in the engine?

What is your head clearance?

What % nitro and plug are you running?

What are the HSN and LSN needle settings now?

What is your idle gap inside the carb?

Are you running the car at sea level?

If you provide the information below, maybe someone can offer some suggestions:

How did you break-in the engine? Just let it goes and screw the HSN

What is your head clearance? No change, default setting

What % nitro and plug are you running? 5%

What are the HSN and LSN needle settings now? Someone helped me to tune. So It's, HSN 2 1/2 turn from close, LSN 1 turn from close.

What is your idle gap inside the carb? I saw it around 1mm and little more

Are you running the car at sea level? on the hill

when you say not stable what is it doing exactly? these motor are designed to run 16% nitro, what plug is in it? what clutch set up? pipe?

Not stable could be other things:

- bad sliding carb
- binding on the throttle movement at the servo (use an extra return spring)
- bad servo
- bad neutral pont servo (trim)
- leak in exhaust system
- leak in tank (cap)
- leak in fuel/fressure lines

Too little nitro 16-20% is best

I ran 5% fuel at first. Its using S6 plug. I detach the clutch now, same result the response is like on throttle when full close.

I suspect the carb is factory defected, the servo is new and in netural prefectly. exhaust, tank and tubes r fine when I use the other engine.

If really a carb sliding problem, so what is the alternative carb can be used with S12 XXX? Nova? Picco?

If the carb is binding you should disassemble the carburetor.
Probably the slide has some flashings from machining.
You could use some Scotch Bright (Steel wool) to remove the flashings. Then smooth it with some polishing compound.

The idle gap on my xxxv with the 5.50mm venturi is ≈.150mm. Thats with 16% nitro fuel.

Yes, I did and re-asemble the carb, smooth now! Thx!

0.15 mm, oic. I set it I think 1mm, it shows from Sat Motor web site.
So what about 25% fuel? Harmfual for the enigne?

might need to add shims to run 25%