Throttle kills motor

[Al Mac]

I have a 1999 25 hp. when I give it gas the motor dies. I have rebuilt the fuel pumps but no go. the motor idles good but wont throttle up. Once it dies it takes a while to restart.

 

[James in Canada]

After it dies is the priming bulb soft? Does pumping the priming bulb while throttling up help?

 

[Al Mac]

After it dies is the priming bulb soft? Does pumping the priming bulb while throttling up help?

Primer is still hard and it takes around 20 min. to start again

 

[James in Canada]

Does it have spark after it dies? If you have a timing light, watch that as you throttle up and see if it loose spark. Does the spark jump a 1/2 inch gap in open air?
It should have a strong, blue spark.
What are your compression numbers?

 

[James in Canada]

Did this "Throttle kills motor" problem develop suddenly, over time or after trying to fix a different problem?

 

[racerone]

A 2 or 3 cylinder

 

[Al Mac]

Did this "Throttle kills motor" problem develop suddenly, over time or after trying to fix a different problem?

It happened at the end of the day. probably 5hr on the water. it now will not stay at idle for more than 10 min

 

[Al Mac]

it is a 3 cylinder

 

[racerone]

Who adjusted the low speed mixture screws ?----What are they set at ?----Adjusted to a dimension to start with or 2 turns as per a friend ?