115 Merc dies at take off?

[wetdrive]

I have a 1984 Merc 2 stroke outboard. When taking off there is no power. If I take off slowley and wiat a few seconds I can power up and it runs ok. If i hit it it dies instantly. The problem is worse when under load but once I get going even when pulling skiers and boarders it runs fine. I have replaced spark plugs, put in an additive in case of water in the gas, rebuilt the fuel pump, checked the carb settings (1 1/2 turns out) and replaced the fuel bulb in the gas line.
Any suggestions?

 

[jimbo8489]

Re: 115 Merc dies at take off?

my 79 I6 had the same problem and was easily fixed by degumming the carbs and replacing all fuel lines (especially the ones on the carbs). the problem i had was it was losing vacuum. after doin that, it stopped hesitating out of the hole completely.

 

[wetdrive]

Re: 115 Merc dies at take off?

How did you clean the carbs? Did you use carb cleaner? If so what brand?

 

[Plainsman]

Re: 115 Merc dies at take off?

How did you clean the carbs? Did you use carb cleaner? If so what brand?

First, order the manual, the merc manuals are best. Sometimes the library has them. Second order a carb kit. Then remove the carbs, disassemble and soak in carb cleaner. Use compressed air to blow out.

 

[Tadd_P]

Re: 115 Merc dies at take off?

keep in mind that you will wanna replace the floats also when you get the carb kit make sure those come with the kit if not buy them seperate.

 

[AMD Rules]

Re: 115 Merc dies at take off?

No doubt you have a fuel issue. Check everything from the fuel tank to the carbs. Any air leaks, or faulty check valves before the carbs will result in a low level in the bowl and a poor hole shot. Do you have trouble starting it after it has been sitting a while?

Chekc all fuel lines, and filter for signs of deterioration.

Its could be as simple as a lean low speed jet. Before digging deeper, try turning the low speed jets out another 1/4 to 1/2 a turn.

Last... performa lync and sync to ensure your timing is bang on when the throttle plates are opening. Its all a fine balance between fuel, air, and timing.... get it right and you'll know it.

Don't spray cleaner in your carbs. Take them off and clean them properly. Install new needles/seats and new gaskets and you're all set.

If not already done, remove and discard the electronic idle stabilizer and plug the small cross-over tubes on top your carbs with a small BB. Both of these things help to ensure your motor will outlast you.

Good luck.