Interesting Weber jetting

[Caprimaniac]

Originally Posted by Eljaro

Repairing the pump jets seat did help in preventing them from dripping while the engine runs. The vacuum inside the Webers was drawing fuel out of some of them. That does not happen now.

Eljaro. You were troubled with too fat condition in the lower end.
Did the repair of the pump jets make you come closer to a solution of the problem?

I run F11 tubes. 165 main and 210 air, very, very fat around 3-4000. Changed to 140/200 and it's a little better. (May be too lean higher on the scale; have not run an A/F- meter yet.)

I consider changing to F15 emulsion tubes.

And what you not see as an option, and I agree some, but still tempted to try: .035 exhaust.

Guess I don't need to ask; you'd tell me to try the F15?

[Eljaro]

Caprimaniac
My situation at this time is:
choke 42
etube F11
main jet 155 (140 is too small)
air corrector 120 (200 will lean you out at high rpm)
idle jet 70
idle holder 100
pump bypass 0.50

I have quite a good setting now, with the plugs having a nice tan color. The repaired pump jets did prevent fuel from being drawn down the throats on idle
I was running a 0.00 bypass with some black smoke out the exhaust and I did also see sometimes fuel dripping out the pump jets. Now with the 0.50 I have a slight bog when flooring suddenly.
I think that has to be an ignition timing problem now.

I was having problems with irregular running engine at around 4000 rpm. I did close the hood scoop to air flowing in and things got better. The engine does not hesitate now at cruising speeds and all the plugs have the same color. Before the # 1 and 5 plugs read rich and the others lean. The engine temperature is more stable now too and stays at 80ºC going fast or slow
But the timing is still erratic at around 4000 rpm. I think the distributor need some work done to it.
With the black stop bushing (theoretical stop limit 18º) in the MSD distributor and setting for a maximum of 36º advance the idle comes down to only 12-13º.
The initial advance should be 20º or higher to give a crisp response but then the max advance goes above 40º which is no good. I will have to check the condition of the stop bushing or make myself a custom on to achieve 20-22º initial advance and and 36º maximum. I will have to go to the stronger spring too, because I think there is some bouncing going on inside the distributor when the centrifugal weights hit the limiter bushing.
And max timing advance in by 2500 is not necessary if you are running 20-22º initial, but rather 3000-3500.

I thing this initial timing should get the bog out of acceleration with the 0.50 pump bypass in place.
I will check the bushing issue post results.

[Hans-Olof Blom]

Originally Posted by Eljaro

Caprimaniac
My situation at this time is:
choke 42
etube F11
main jet 155 (140 is too small)
air corrector 120 (200 will lean you out at high rpm)
idle jet 70
idle holder 100
pump bypass 0.50

I have quite a good setting now, with the plugs having a nice tan color. The repaired pump jets did prevent fuel from being drawn down the throats on idle
I was running a 0.00 bypass with some black smoke out the exhaust and I did also see sometimes fuel dripping out the pump jets. Now with the 0.50 I have a slight bog when flooring suddenly.
I think that has to be an ignition timing problem now.

I was having problems with irregular running engine at around 4000 rpm. I did close the hood scoop to air flowing in and things got better. The engine does not hesitate now at cruising speeds and all the plugs have the same color. Before the # 1 and 5 plugs read rich and the others lean. The engine temperature is more stable now too and stays at 80ºC going fast or slow
But the timing is still erratic at around 4000 rpm. I think the distributor need some work done to it.
With the black stop bushing (theoretical stop limit 18º) in the MSD distributor and setting for a maximum of 36º advance the idle comes down to only 12-13º.
The initial advance should be 20º or higher to give a crisp response but then the max advance goes above 40º which is no good. I will have to check the condition of the stop bushing or make myself a custom on to achieve 20-22º initial advance and and 36º maximum. I will have to go to the stronger spring too, because I think there is some bouncing going on inside the distributor when the centrifugal weights hit the limiter bushing.
And max timing advance in by 2500 is not necessary if you are running 20-22º initial, but rather 3000-3500.

I thing this initial timing should get the bog out of acceleration with the 0.50 pump bypass in place.
I will check the bushing issue post results.

So the 42 mm chokes above should be 40 mm?

[Eljaro]

That was a mistake, it was the 40mm ones.