Originally Posted by mblgjr

Never run OS plugs in a Novarossi. Taper is different; now that you have seated an OS plug into the button, you may have to buy a new button.

Use 0.80mm total head shim stack. .30/.30/.20 for 30% nitro. I had 0,80mm, but the plugs become broken, but I will test again

Use 0.75mm for 25% or 0.70 for 20% Ok I will test, i used to run 25%

Use Novarossi C6TGC glowplug, or OD77T; or OD97T. C6TGC preferred; otherwise start with 77T.

I assume you meant 41029 manifold for Mugen? Yes

Pair with 9901 pipe.

Remove fuel tank from vehicle. Pressure test the tank in a soapy water solution (submerge tank). Place finger over fuel pickup, apply pressure by blowing on the pressure line. Observe results to see if any bubbles are seen escaping the tank. Any kind of air leak will cause tuning issues. , Ok I will do it

Run all fresh pressure/fuel lines on the car.

Replace all clutch shoes and ensure they are operating properly.
I will check all, but I dont have any issue with my other engine

The following statements are based on running the engine in a 1/8th buggy on a typical dirt-track in a racing environment...and the engine being broken in (at least 2-quarts of fuel or more).

6.5mm carb insert.

Place LSN 1/8th turn in from flush.
Place HSN 1/2 turn in from flush.

Set idle speed to have 0.50mm air gap (set with restrictor removed), or start the engine and adjust it accordingly once warmed up to operating temp on the starter box. (I'm betting it's way off).

Once running at operating temp, adjust the HSN until proper performance is achieved. With a head temp of 220F- 260F; the idle speed should be stable and fairly low.