1973 50hp Merc 500

[Trihull73]

SN 3720573, I have good RPM climb with the neutral warm-up lever, but can only achieve 6.2mph on the lake, and the engine isn't over revving. Is it a linkage issue? It feels like the throttle lever hits a dead stop when pushed forward, and has a lot more travel with the distributor disconnected.

 

[Texasmark]

SN 3720573, I have good RPM climb with the neutral warm-up lever, but can only achieve 6.2mph on the lake, and the engine isn't over revving. Is it a linkage issue? It feels like the throttle lever hits a dead stop when pushed forward, and has a lot more travel with the distributor disconnected.

Give Chris 1965 a ping.

 

[racerone]

Most motors will rev up in neutral.----That means nothing.-----Do a compression test , post the numbers.-----Do you have spark on all leads that jumps a gap of 3/8" or more, yes or no ?------Have you confirmed that both carburetors are clean and that they both open fully ?----Does bulb on the hose go hard , yes or no ?

 

[Trihull73]

Thanks for the quick response.
Compression:
1-124
2-125
3-123
4-120
Does the fuel bulb stay hard-yes
Spark jump awesome on all 4 cylinders
Carbs clean and open-yes
This is my frustration, as well as the 73 Glastron, I have a 67 Larson with the same, but older motor that runs sweet.

 

[racerone]

Some will argue.----Check that plug wires are on correct cylinders.-----Clean distributor cap insides.----Perhaps run motor in the dark to see if spark leaks out somewhere.--------Check reed valves-------Check for blockage in exhaust tuner.-----Check belt timing.----This should be easy to figure out what is wrong.

 

[Trihull73]

Will do, thanks