1978 Mercury 1150 What the heck is going on here???

[tahoeking]

I have a '78 Merc model 1150 that will run fine on the hose. However drop her in the water, toss her in gear and the best I can get is about 2100 RPM's. If I push the throttle past the 3/4 mark, she wants to bogg down. (Sounds a lot like my wife. However when I kick the Merc I don't go to jail) Comments/suggestions/shure-fire cures all welcome!

 

[Charlie61]

Re: 1978 Mercury 1150 What the heck is going on here???

sould like your timming advance needs ajusted .you need a ser manual for that tradebit.com has many manual you can down load for your motor for about $5.00

 

[tahoeking]

Re: 1978 Mercury 1150 What the heck is going on here???

Hey charlie.... thanks for the reply. Yep, I kind of figured it MIGHT be a timing issue. The motor was purchased for close to nothing. Had a bad lower end and had been sitting in a garage for a few years. The lower unit is now working well and reinstalled (obviously). My very first lower unit "rebuild"..... and hopefully my last. None the less, it was a real education. If nothing else I learned/invented quite a few new cuss words!

I just don't understand why the motor will quickly run up to the 5,000 RPM mark on the hose yet struggle as it does in the water. I would think with a timing problem the motors response would be the same in either enviroment.

 

[JB]

Re: 1978 Mercury 1150 What the heck is going on here???

Your outboard is NOT running fine on the hose. It has no load on it and is running on at least one dead cylinder.

Revving a 2 stroke outboard with no load is an invitation to runaway and disintegration. Don't do it.

Please drop the large type.

 

[Charlie61]

Re: 1978 Mercury 1150 What the heck is going on here???

you are going to need to do some more to that motor if have not done so.

 

[Earp]

Re: 1978 Mercury 1150 What the heck is going on here???

I have a '78 Merc model 1150 that will run fine on the hose. However drop her in the water, toss her in gear and the best I can get is about 2100 RPM's. If I push the throttle past the 3/4 mark, she wants to bogg down. (Sounds a lot like my wife. However when I kick the Merc I don't go to jail) Comments/suggestions/shure-fire cures all welcome!

Had the same problem. Check the fuel pump diaphragm first, make sure its not crispy or hard! for what its worth just get a rebuild kit any way. If that dosent help move on to the fuel supply hose and primer bulb, if they are over 5 years old they could be the problem.... start with the cheap stuff you can weed out first, dont mess with the timing till later...good luck!