major power loss

[captainx]

I have a pontoon boat with a Mercury/Mariner 40hp . Two days a go it was running fine. I could get it to full throttle and we could get around the lake just fine. Now I can't get get past 1/4 throttle with out the engine dieing . I can start the motor in neutral and put it in a pretty fast idle but the moment I put it in full throttle blam the motor shuts off. Any idea what might be wrong? I have a quicksilver remote just for fyi.

 

[hondon]

Re: major power loss

Could be as simple as a broken throtle link connector ,but I doubt it.More likely is water in your fuel.At any rate do ,or have someone do , a compression and ignition output check on this engine to get you to square one. Then take your fuel sample to check for contamination.

 

[Rex]

Re: major power loss

I WOULD SAY THE TIMING HAS CHANGE ON YOU.<br />FULL GAS TAKE THE PLUG OUT AND CHECK<br />YOU TIMING. MAKE SURE THE PLUG ARE ON THE <br />BLOCK OR YOU COULD BURN SOMETHING.

 

[Fouled Plug]

Re: major power loss

I seriously doubt the timing has just decided to jump on the motor. Try the fuel first, as water will cause those symptoms. A water seperating fuel filter is always a good item to have in the line. I like hondon's advice the do a comp/spark check. Kind of like a physical for your motor! It also gives you a baseline to compare to in the future. Good luck!