HELP! Coil/Power Pack Problem?

[nsmith74]

I have a 1973 Mercury 9.8 hp, I recently rebuilt the carburetor completely and put new spark plugs in it. It's also had a full tank of Stabil ran through it. The motor starts great and will idle, it will even throttle all the way up to max and run and then go back down to idle fine, but once I put it in gear it can only go to about half throttle and dies out.

I am very very green and new to boating, but I am relatively sure I need a coil/power pack and that I am only running on one cylinder, this is based off of research I've done on here and various other locations and guys I have spoken with who know far more about boats than I.

Can someone confirm my speculations that I'm running on one cylinder and that I need to get a coil pack? Or offer up another suggestion if you don't think this is the problem, and a SOLUTION for me? I would really like to get this motor running great soon.

 

[gonefishy]

Re: HELP! Coil/Power Pack Problem?

First I would confirm whether you have spark or not by pulling the plug wires and checking the spark to ground over a 3/8" gap. A compression check of the cylinders is also recommended.

 

[BonairII]

Re: HELP! Coil/Power Pack Problem?

Did you test the motor on the water or on muffs?

 

[nsmith74]

Re: HELP! Coil/Power Pack Problem?

First I would confirm whether you have spark or not by pulling the plug wires and checking the spark to ground over a 3/8" gap. A compression check of the cylinders is also recommended.

The cylinders were checked by my father a month or so ago and they had great compression.

Bonairll I have done every bit of work with it mounted in a barrel not on the water...

I'm so confused that it starts and runs so well and in a barrel it will throttle ALL the way out and sound and run great, but once in gear in the water it just bogs off and dies past half throttle?

THANK YOU guys for your help!!!

 

[BonairII]

Re: HELP! Coil/Power Pack Problem?

The motor is not "under load" in a barrel. Motors performing well in a barrel....then crapping out in the water is very common.

Did you pull the plugs after it died on the water? If so, were either of them wet with fuel?

 

[nsmith74]

Re: HELP! Coil/Power Pack Problem?

The motor is not "under load" in a barrel. Motors performing well in a barrel....then crapping out in the water is very common.

Did you pull the plugs after it died on the water? If so, were either of them wet with fuel?

I did not, I will do so today though.

 

[Sunfish12]

Re: HELP! Coil/Power Pack Problem?

Did it run great before carb rebuild? Sounds like carb needs more adjusting.