Mercury 25XD won't keep running/hard starting

[skyking897]

Had this motor given to me. Not sure of the year but it's probably late '80's, 25XD long shaft tiller. Was told it hasn't run in years. It will not start unless I spray some fuel into the carb throat and then it will only run for a few seconds. It has good spark and compression on both cylinders. First thought is to tear into the carb and fuel pump, cleaning and replacing what's needed. Anything in particular I should be looking for when I do this? Or should I be going in a different direction?

 

[flyingscott]

What is compression should be should be above 100 psi each within 10% of each other. If that is good make sure you buy the repair kit that has the primer and fuel pump diaphragms and gaskets in it. You should also buy a water pump assembly easy to install when the carb is out as the shifting linkage is behind it.

 

[DavidMoore]

It's the way I would be going,

+ 1 on changing the water pump, not doing it could be very expensive.

Also check all the fuel lines are in good order, you don't want your freshly cleaned carbs to get bits of rubber in them.

 

[skyking897]

Outboards are a bit of a mystery to me. Give me an I/O and I can do almost everything myself. Got a couple of questions.

flyingscott...not sure what this primer is you speak of. do you mean the squeeze bulb in the fuel line?
DavidMoore.... new fuel lines are a must, have heard too many horror stories of problems with old lines.

If I buy a water pump assembly, is it just a bolt on? I ordered a service manual, so until I get it, I'm kind of in the dark here. Thanks for you advice.

 

[flyingscott]

Ok the primer I am talking about is in the carb itself it replaces the choke system. When you take the carb off you will see it. The water pump assembly involves dropping the lower unit. 18-7212 is the sierra kit for your carb. Be careful opening it there are small parts in it also be careful taking the primer apart there is a spring and small steel ball in it.

 

[skyking897]

Thanks for the info.