2001 4 stroke 50 hp mercury power loss!!

[swantek1]

hi,

this weekend I had picked up my boat from repair shop, it had a crack cylinder on the power tilt and trim, plus i had the prop replaced cause it was chewed up a bit. The prop I don't know the size, but do know it was a 13 pitch. I told the mechanic that I was feeling sluggish and only maybe getting 5500 rpms. So he did his research and bumped it to a 11 pitch. I took the boat out and wow what a approvement that made me happy. I ran the boat later that night, fishing and the next morning out to the fishing hole. Rain started to look like a might, so we started to head in. I was running almost 6000 rpm out of the cove and turn the boat towards dock. After the turn the motor lost power. I was running about 3800 rpm. I tried shutting it down and starting again. When i mash the trottle foward the motor shakes a bit and then goes to the 3800 rpm, no more. I get the boat back to the shore and to the mechanic, I told him I was thinking plugs. change the plugs and said the bottom plug looked okey but not great. He also said the trottle cables and mechanisms were working okey. He also said I could of got water in the gas??? Okey so I took the boat back out to see if plugs were it nope, no cure. I ran the boat alot afterward but still can't get the rpms up. The motor runs fine trolling and slow takeoffs. I brought the boat home hoping to avoid any mechanical expenses if possible. Anybody have any recommendation where to start?

thanks

 

[swantek1]

Re: 2001 4 stroke 50 hp mercury power loss!!

How about sticking in some heet in the gas to get water out?

 

[Don S]

Re: 2001 4 stroke 50 hp mercury power loss!!

Don't go dumping heet in an outboard tank, not good for the engine. Check/change the fuel filters/water seperator if you have one. If there is water in the tank, you have to pump the water out of the tank
NOTE: Don't empty the whole tank, just use a small tube and an electric fuel pump and suck the water out of the low spot.

 

[swantek1]

Re: 2001 4 stroke 50 hp mercury power loss!!

Before Don's post to this tread, I already had dumped heet into my gas tank and did some pumping on the ball. But luckly I had not run the motor.

My Problem is fixed atm. For those who have had power loss, rpm loss like you lost a cyclinder, this is simple and easy to do and probably a great start.

I dumped my whole gas tank, since I don't use oil mixed gas, I stuck it in the truck so I didn't waste high price fuel. While I was empty and had the tank out of the boat I took the valve piece off to check it out, only 4 screws to take out. My fuel gauge on the tank wasn't working so this gave me a great opportunity to fix that which the float was caught behind the valve tube inside the tank, now I have my fuel guage back. Clean everything, checked the screen to make sure it wasn't plugged, ect. Then I put everything back in the boat, with a new ball pump and line. Went to Orielly Auto parts and grabbed a can of SEAFOAM. Went the the gas station and got fresh gas and dumped the seafoam in it. The whole can!!!

Ran the boat around our local lake in Columbus Nebraska. I took 1 lap around the lake, the boat still ran crappy like it had before. After 1 lap around the lake the boat came out of it and started to run perfectly. I made 1/2 lap after that and the motor killed on me(like it was passing more junk). After that I started the motor and did 3 more laps with no problems until rain came in. I am believer in seafoam now. I always used it, but I do know now that it probably cured my problem.

Another question for you guys. I was told by a friend that on any outboard motor, you should unplug the gas line to the motor or on the tank. Then run the motor out of gas, when you are done using it and the boat will be sitting for a period of time. Is this true about all outboards and a good recommendation?

Thanks Don for your help on the heet issue.

swantek1

 

[cr2k]

Re: 2001 4 stroke 50 hp mercury power loss!!

Yes this is good practice. with 4 strokes it empties the carbs (run dry in the water to avoid burning the water pump impeller) if there is any junk in gas and left in carbs it will accumlate. On a 2 stroke if you dont do this the gas evaproates and leaves the oil in the bowls. Over time the oil will build up and foul the plugs.