boner,
May be too lean on HSN. Try starting from 1 1/2 turn LSN, 4 1/2 turn on HSN.
If anytime your plug coated with fuel, meaning too rich.

Tell us more when u run the engine again. Good luck

Boner, how many shims are under the button? Or maybe measure them together. It almost sounds like you're overshimmed. Too much fuel in the combustion chamber. Btw, when I used a MT12 carb, i was running the LSN a little over 1 turn out.

Just got back from tuning. Surge you are right about shiming, 1 shim makes a lot of different. If I'm in Cali, I'm sure TG777 will kick me in the butt for not listening to him. Somehow the engine doesn't seem to have the acceleration used to have and it like to peak 280F no matter how rich I set on HSN (tried 5 1/2 turn out). Maybe it's because I'm running on a open parking lot + warmer plug. Going to do more tuning tomorrow after I pick up a new fuel bottle, don't you just hated when things are start to working well and fuel bottle decide to tear apart?

Hi Guys,

With the experience so far with the PS12 give me your base settings.

I've got a carb from an MT12
Running 3 shims
3 1/2 top
2 bottom

Novarossi No. 6 plug

I can start the engine no problem, it will run steady as long as I keep the glow starter on the plug, when I take it off it dies in 10 secs. It sounds like it is loading up.

I attempted leaning out the bottom end & top but felt I could start doing some harm so I stoped.

I did try a No. 7 plug but it seemed worse.

So what to do . . . . . . .


Thanks in advance

Edward,
Did Leo like the 1/8 body I painted for him?

Hi Kevin.
It is too reach on the bottom, lean it to 1-1/4-1-1/2, will not harm.

Hey, I was thinking you are already gone to San Jose.
Yes , he love it and I already made all holes. just wait for next practice.
Did you tune 21 BRB P/S set ?
See you at RAMS next Sunday

listen to TG777 he know his stuff. you low end is on rich side and use cold plug this engine like it a lot. my needle setting with mt12 carb:LSN 1 1/2 HSN: 4 1/3 run like a charm (180F)

Hi Guys,

Thanks for the replys.

Boner when you say run a colder plug do you mean a 7 instead of a 6 (Novarossi range)


Many Thanks

Just ran the engine again with the new settings:


Bottom 1 1/2
Top 4 1/2

Tried a No. 6 & a No. 7 Novarossi plug


Engine will not idle without the glow starter on the plug.

It starts OK but when I take the glow starter off, it dies?

Idle is set high

Any suggestions?

What is ambient temperature now?
Try hotter plug-in Europe if it is cold, #5 might work better on idle.
But still to reach on bottom. Go for 1-1/4

How many shims should there be?

I've got 3 shims & was told one was removed before I got the engine, is this correct? Should there be 4?

Temp 11c / 52f

I don't have any no. 5 plugs!! I've never needed them in the last 7 years running .12's.


The engine runs fine with the glow starter on it but now, with the new settings, it cuts out the second I remove it.

I'll try again with a leaner bottom end.

Forgot to mention, I'm running 16% nitro, could this have anything to do with shims?


Thanks

Changed bottom to 1 1/4.

Still no difference.

Will have to wait until I get some no.5's.


I find it hard to believe thats this is the problem, but I'll give it a try.

you have to ask TG777 on head shim. By the way, did you check the temp of your engine when it flood/flame out? It's a pain to tune an engine when it's cold. I probably will put the ignitor on until engine reaches 45+C