Everything done but low rpm at WOT. Distributor spring?

[Scott Danforth]

What is the coil voltage? You could have weak spark.

the coil will fire until voltage is below 9 volts.

 

[Scott Danforth]

Yes, I did these videos out on the water and went to full load WOT. For me that is 3500 rpm. Yes mecahnical pump. The rpms did and do stay steady at whatever rpm I try, so it is not like the carb is bogging or waivering. On the first one the reading was 3 and then at WOT it was flickering between 2 and 3. On the 2nd it started at 4 and then went down to 3 and then flickered between 2 and 3. A post above I was told that anything between 2 and 7 is ok, so I am not sure if this is acceptable. I have checked the pickup and anti-siphon and they are ok.

yes, anything above 2 psi and the floats open

then the next thing is the proper sized carb.

 

[drewm3i]

the coil will fire until voltage is below 9 volts.

Maybe, but the spark gets progressively weaker. Not sure if this is HEI/EST or points, but the former really needs close to 12 volts to run well. I've seen Mercruisers have no spark with just under 9 volts (like 8.75).

OP, you should test coil voltage with a voltmeter. It can't hurt.

 

[VancouverBoat]

Maybe, but the spark gets progressively weaker. Not sure if this is HEI/EST or points, but the former really needs close to 12 volts to run well. I've seen Mercruisers have no spark with just under 9 volts (like 8.75).

OP, you should test coil voltage with a voltmeter. It can't hurt.

Just across the - to + on the coil?

 

[Scott Danforth]

Just across the - to + on the coil?

No. Read ground to coil +

The negative is pulsed by the dizzy

 

[VancouverBoat]

yes, anything above 2 psi and the floats open

then the next thing is the proper sized carb.

But why at 1000 rpm would psi be 7 sometimes like today and then 3 on other times...? It seems to vary by the day.

 

[Scott Danforth]

You need to take fuel pressure readings with the motor at WOT and under full load for a while

What you are seeing is the float doing its job and the needle/seat opening and closing

However if your pressure is fluctuating that much, you have a restriction up stream. Such as anti-siphon valve or pickup tube filter (remove the filter)

 

[VancouverBoat]

You need to take fuel pressure readings with the motor at WOT and under full load for a while

What you are seeing is the float doing its job and the needle/seat opening and closing

However if your pressure is fluctuating that much, you have a restriction up stream. Such as anti-siphon valve or pickup tube filter (remove the filter)

Thank you so much for continued ideas. I did check the inlet and the anti-siphon. The thing is I do not have hesitation or waivering like the fuel pressure is too low or getting held back.. I will try it more times. In the mean time I have lower pitched prop (15p instead of 17p) that arrives soon and will see if that helps in any way.

 

[VancouverBoat]

Thank you so much for continued ideas. I did check the inlet and the anti-siphon. The thing is I do not have hesitation or waivering like the fuel pressure is too low or getting held back.. I will try it more times. In the mean time I have lower pitched prop (15p instead of 17p) that arrives soon and will see if that helps in any way.

No result with the lower pitch prop. I think I just have to leave all weight including mistresses behind.

 

[Scott Danforth]

If you were in Florida, I would loan you a bigger carb to try

 

[VancouverBoat]

If you were in Florida, I would loan you a bigger carb to try

Appreciate that, thank you.. I was just in Tampa with flights cancelled right in the path of the hurricane.