View Full Version : Motor help needed

09-22-2008, 06:13 PM
I've never had a problem with my motor until the last time I ran it. It started up just fine and took off without any problems. Halfway across the lake it bogged down without any warning and full throttle was only getting me about half the speed it should have.

I'm thinking it may be bad fuel and I am going to change it out and I also picked up some new spark plugs for it as well.

Am I thinking right, or could this be something a little more serious?

09-22-2008, 06:24 PM
Check your primer bulb on your gas line. Sometimes the check valve (ball) inside the bulb gets stuck or varnished over and won't hold pressure. It can also have a crack in the bulb that is sucking air. Does the bulb pump up hard? (no smart comments please) Also, if your motor went to half throttle, you may be possibly overheating or low on oil. Some motors have this saftey feature on them. If you tell us what kind of motor you have then maybe we can help you a little more.

09-22-2008, 06:35 PM
Sorry, the motor in question is a '96 Mercury 90 hp.

It's not overheating or low on oil, but I haven't checked the bulb yet. Suppose if nothing else I could replace it as well. Thanks for the reply.

09-22-2008, 06:44 PM
No problem Cope. Hey, also check your throttle linkage. I had a keeper that held the cable in place pop off mine once and done about the same thing.

You can check your bulb by walking out to your boat and pump it up and then go back in a little bit and see if it is still hard. Them things are notorious for dry rot.

Hope everything works out!

must buy my fish
09-22-2008, 07:09 PM
I have a 96 30hp, It did the same thing. It turned out to be the coil for the top cylinder. What was funny was it might run fine for a while then load up, it did that 2 or 3 times before I found the problem.

09-22-2008, 07:16 PM
Cope I went throught the exact same thing...with a 1996 Mercury 60. I did the same thing as suggested to you...changed the fuel...and replaced the primer bulb and spark plugs...did not help. Mine would hit wide open for a couple of minutes and bog down to about half the speed. The first trip to the mechanic he cleaned the carbs...said the bottom one was stopped up. Back on the lake, one hour later did the same thing. The second trip to the mechanic he rebuilt all three carbs and put in a new fuel pump kit. Runs better now that it ever did. So I am voting for cleaning or rebulding the carbs.

09-22-2008, 07:41 PM
Thanks for all the input. Sounds like it could be numerous things now lol.

09-22-2008, 07:44 PM
More than likely a fuel problem. Put a new bulb on it and check hoses going to fuel pump for dry rot. If this does not fix the problem, clean carbs and rebuild fuel pump. To be safe you might just do everything at once if it is all original. Be sure to take a look at the reed plates while the carbs are off. If it throttles up good to half throttle it is probably not ignition. A fresh set of plugs will NEVER hurt a two stroke. PM me if you need help, I will be happy to help you.

PawPaw "gene"
09-22-2008, 07:53 PM
Cope, you can do all the above 1 by 1 and try them out or all at once and try it out. If its fixed pat yourself on the back. Or----- you can take it to the mechanic man and let him do the guessing, he do all or most of the above but the difference is he will charge you for each and every one plus labor. If you do all of the above then he can only recommend the carb rebuild if he feel thats it or an electrical component. I say get your hands dirty and good luck.