question about mercury throttle control

[clmdpk2]

Hi everyone. I'm a new member and also a new boat owner. I'm finding out how little I know about boats every day!!! We have a 25 foot pontoon boat with a Merc 50 hp engine. It has been running ok until yesterday when the engine stalled while we were out. Had to be towed in and could not get it started again. Once back at dock someone suggested it might be something with the throttle control. We are now able to get it started with the throttle in the wide open position, but it stalls when I put it into neutral. The engine runs fine when the throttle is up but stalls immediately when I try to put it into neutral. A friend told me take the throttle cover off and inspect the inner workings where the button that pops out when put into neutral lies. He said sometimes the button gets stuck and doesn't truly pop out. I tried to pry the housing cover off from the outside but it won't come off. There is no screw or bolt to take it off. There is a small hole on top, but doesn't seem to have anything to do with getting it off. On the inside of the housing are four screws that are thredded but have rubber like gromets on them and it also doesn't want to come off. Can anyone enlighten me as to how to get the cover off, and what to look for once it is off?? Remember, I'm really a dumb novice!!!!!

 

[SpinnerBait_Nut]

Re: question about mercury throttle control

Welcome to iboats.
Remember, all of us were new to boats at one time or other.
Let's get this up to the Mercury Outboard and Mariner Outboard troubles and repair forum.

 

[Laddies]

Re: question about mercury throttle control

There is nothing wrong with the throttle control, you have either lost spark on 1 or more cyls. ck them for spark or it has a flooding condition chances are you have a inlet needle stuck in 1 of the carbs or a fuel pump with a bad diaphram

 

[crabbie]

Re: question about mercury throttle control

I don't know enough to say whether the controls are a problem, but having just had to replace mine, I know a little bit about taking controls apart.

Your controls don't sound familiar, though. The two types I've had are from the 70s and 80s, and both have to unmounted from the side of the boat before you can take them apart, as the screws are on the back. But be careful, sometimes pieces will come springing out at you when you open the box up.

If you do get it open, what's inside won't make any sense initially, so might not be helpful. Better to try checking the motor, first.

Actually, for SURE check the motor first: if you really think it's the controller, then you can disconnect the cables from the motor and push on the throttle lever yourself to see if you can replicate the problem. If you can, it's a problem with the motor. If not, well... could still be either. The joys of debugging...

rodney (only slightly less dumb novice)

 

[clmdpk2]

Re: question about mercury throttle control

Thanks for the tips. I had someone who "supposedly" knows what he's doing look at it and he said the throttle control was ok, but that in checking the compression, one cylinder was testing at about 90 while the other two were at 125. He says this is the problem and that the engine is no good now and needs to be replaced! I don't know enough about motors, but think they can be repaired. Is he just trying to sell me a new motor?

 

[renny1]

Re: question about mercury throttle control

i had the same sort of readings and one of my pots was only reading 90 so i de-carboned it (if thats the word) an she is now reading roughly the same try it before you get ripped off