1994 Mariner 200 efi trouble keeping rpm up

[jkillion]

Hi,

I recently purchased a bass boat with a 1994 Mariner 200 efi hanging off the back (SN 0G006188). When I first fire it up, it runs like a champ, I can keep 5100+ rpms without a problem. After running it a while, it will be more difficult to keep it at that rpm, and it will start holding around 4000rpms. When I try and push it past 4000rpms it will slow down to 3700, then go back up to 4000, and then slow back down to 3700, etc. The other day it wouldn't get over 2000rpms which makes it impossible to get out of the hole in my boat. The solution I have found is to cut it off for a few minutes, fire it back up, and it will rev up again and get me going. I should note that this appears to only happen when the boat is in gear.

When I was having the issue where it wouldnt get past 2000 rpm, I put it in neutral and was able to rev it up past 4000 no problem. Originally I thought it was a fueling problem, so I replaced the bulb line and the fuel filter. Now I think it is lending itself to more of a spark problem.

Does anyone have any experience with an issue like this?

Thanks,
Jud

 

[Dukedog]

send me an email and i'll send ya tha pdf manual if I can find it again on this lap top... it will tell ya how ta do comp, 'lectrics, fuel delivery test...sounds more like a fuel problem.. maybe high pressure 'lectric or maybe mechanical pump.. did ya change tha little coned shaped filter in tha "U" shaped hose between tha vst and pump?.......

 

[jkillion]

So I have a little more information here. The boat will rev up nicely right after it turns on and I can get to 5100rpm. It will run that way for about 30 seconds and slowly start losing RPM until it finally comes off plane and I have to shut it down (entire process is 1.5-2 minutes). I can turn the engine off and immediately turn it back on (previously I was waiting a few mintutes) and it will again speed up just fine and then start losing RPMs again. Not sure its a fuel problem since I can just cut it off and cut it back on to fix it.

Any ideas?

Thanks,
Jud

 

[jkillion]

Any ideas? Does the eletric fuel pump every quit running hard until you reset it if its going bad?

Thanks,
Jud

 

[Faztbullet]

Zounds like its starving for fuel, replace the mechanical fuel pump diaphragm...