Monobloc settings-what jets are you guys using?

[tombeau]

I'm curious to know how you guys have got your monoblocs set up
A10/A7s all seem to be pretty much individuals in what they like, but I'm trying to solve a spluttering problem that appears at  slow traffic speed and at about 40mph.

I'm running a 389 currently set up like this:
330 main
 25  pilot
   3 1/2 slide
needle position 4
106 needle jet

I'd be interested to hear your views

I'm running an airfilter and beetle tailpipes, Manual A/R Road Rocket motor with standard compression pistons and spitfire cam. Fitte with N3cs

Cheers,
Tombeau

[england kev]

Tombeau, I too am running a 389, no filter, 3-1/2 slide, needle at position 3, 400 main (just gone up from a 290) I will tell you the other settings tomorrow, but my motor is SR spec.

[a101960]

Main jet 420
Slide 3
Needle .106 position 2nd from top
Pilot 25

I tried a 3 1/2 slide and the engine did not like it one little bit.

[tombeau]

Cheers for the responses guys!
A101960: Are you running an airfilter?
Kev. I just went up from a 290 to the biggest they had in the shop.
My plugs are starting to look brown now...well "hearing-aid beige" guess I need to go up a bit more, although I know the main jet is not meant to affect low speed running.
Tombeau

[a101960]

Tombeau. No.There is no air filter fitted, I run with the standard short bell mouth. Incidentally, the specification that I have listed are the factory settings for 1962 year RGS and Super Rocket with the "big valve head". The plugs are a lovely tan colour. It took a bit of experimentation to get things right. I have found that my engine runs best with Champion N3C plugs. N4C plugs tended to foul, as did NGK plugs. There were times when I thought that I would never get the mixture right. I tried different jets, needles, slides, and plugs, and it caused a great deal of frustration and heart ache (especially all the aggravation of taking the carb off so many times). With the 389 it is not a simple task. Anyway what all this proves is that the factory spec is spot on, it was the plugs that were wrong. Since fitting the N3C's I have never looked back.

[england kev]

Tombeau, I too am running a 389, no filter, 3-1/2 slide, needle at position 3, 400 main (just gone up from a 290) I will tell you the other settings tomorrow, but my motor is SR spec.

The other settings are, 106 needle, and 30 pilot.
I was advised by Amal to change to a 3 slide, and raise the needle one slot, as I thought I was having starvation problems.

[tombeau]

Thanks guys,
I wont be running without my filter, but I think I some have room to go up in jet size.
Upon recommendation, I tried a 30 pilot jet once, the bike just wouldnt start after I fitted it.
I'm learning to adapt to Monoblocs after years of running a tired old concentric.
Cheers,
Tombeau