1995 30 HP Johnson full throttle in reverse and neutral, bogs down in forward

[henson2205]

I have a 1995 30 HP Johnson. The engine idles perfectly. If I put it in reverse or neutral, I can go to full throttle with out any problems. When I place it in forward, I can throttle to about half before the engine goes sluggish. If I place my hand half way over the intake to the carb, it throttle back up but only to the same speed as half throttle.

When I turn the throttle all the way, it will run at full throttle like normal for a few seconds before bogging down.

Here are the things I have already done:

Rebuilt carb with carb kit w/float
Rebuilt the fuel pump
Replaced the spark plugs
Replaced the power pack
Replaced the ignition coils

Both spark plugs are firing. I already check to make sure the carb wasnt over opening.

Please help me! I cannot figure out why it will only maintain at half throttle but dies down at full throttle.

 

[Bosunsmate]

Re: 1995 30 HP Johnson full throttle in reverse and neutral, bogs down in forward

Have a look at the plugs after it bogs down.
Did you change the float seat?

 

[henson2205]

Re: 1995 30 HP Johnson full throttle in reverse and neutral, bogs down in forward

I did change the float seat. I put in a new needle, brass fitting and washer. I just did a pressure test to see if i had an issue and they both came out at 100 psi. When I pulled the plugs, one plug was a little blacker that the other. Thanks for the help.

 

[Bosunsmate]

Re: 1995 30 HP Johnson full throttle in reverse and neutral, bogs down in forward

How many seconds will it run at high throttle for?
Have you checked that the timing is advancing?
Ive seen the split pins rust on motors and then joiners fall out so when the throttle is advanced the timing doesnt match and it will bog down
Reverse and neutral dont put much strain on the engine