1990 mercury 135 wide open throttle problems

[bowtiekidd]

I bought a 90 model venture that has been sitting for a year, I took it out this morning it cranked fine ran it across the lake came back to the ramp to pick my friend up. I hit the throttle and the boat would not go it just stumbles and wont run wide open. The boat idles fine and cranks right up but will not run wide open throttle. I am pretty sure the carbs have never been rebuilt and it smelled like it was running rich. The temp gauge was not showing hot and it showed to have oil pressure it just does not make since how it ran fine for 2 minutes and then just stopped.

 

[Chris]

I bought a 90 model venture that has been sitting for a year, I took it out this morning it cranked fine ran it across the lake came back to the ramp to pick my friend up. I hit the throttle and the boat would not go it just stumbles and wont run wide open. The boat idles fine and cranks right up but will not run wide open throttle. I am pretty sure the carbs have never been rebuilt and it smelled like it was running rich. The temp gauge was not showing hot and it showed to have oil pressure it just does not make since how it ran fine for 2 minutes and then just stopped.

Welcome aboard - nice to have you with us.

I would check the obvious things first, like pulling the plugs and see how they look. If possible, check and see if you've got spark on both banks of cylinders, I would think you've got two powerpacks, one for each bank. If a pack goes or is acting up, you'll most likely find one side not firing or also wet. That's a common Merc problem.

And it goes without saying that running with dirty carbs for too long on any outboard, especially a big one, is a receipe for a powerhead rebuild, as you're likely to be running lean.

-Chris

 

[old johnson]

Also check the fuel lines make sure they are not deterorating this will cause the carbs to clog and this is caused by the ethonol in the gas. If you grab and rub the gas lines see if it leaves your hands black that is a sign that they need replacing. Also you could have junk in the carb bowls once stirred it clogs. Once you verify its not fuel check for spark on all six. Rick

 

[Chris E]

while you're at it, check the oil lines, they rot as well, a very expensive fix.