will not take off under load

[sheree]

we have just purchased a 1987 70hp mercury we check the compression on all 3 and they all showed 110 but when we took it to the water runs fine until you try to take off and it lugs and doesnt seem to have any power. we took all 3 carbs. off and cleaned and rebuilt them and took it back and is still doing the same thing. we think maybe it is only running on one cyndler when we remove the plug wire off either the second or third carb the engine will go dead. seems to be running fine until you put in under load. could this be electrial such as power pak?<br />hope this is enough information i am putting this in for my husband and i dont know if i worded all of the correctly.<br />thanks for any help

 

[Scooby]

Re: will not take off under load

Try running the engine at night with the cowling off and look at the coils, wires and boots. Sounds like you have a spark leak.

 

[cclemon]

Re: will not take off under load

Sheree,<br /><br />Sorry I don't know what is wrong with the motor, but I would like to say you did a great job wording the post.

 

[xp150]

Re: will not take off under load

Try changing spark plugs, sounds like they may be fouled. Good luck

 

[BKool68]

Re: will not take off under load

When you pull the 1st wire does it stay running?<br />If so that is your dead cylinder.

 

[Backlash]

Re: will not take off under load

Hey Sheree,<br />Sounds like a bad coil on #1. Switch coils with #2 or #3 and see if the miss moves to that cylinder. If so, replace the coil. Good Luck. <br />Backlash

 

[sheree]

Re: will not take off under load

thanks everyone, we took it by a boat repair shop today and they couldnt work on it for about 3 weeks but they did check it with a ohm meter and said they thought it could be the stator had gone bad. we have it on order so if that works we will let you know.