18hp mercury problems starting

[VanDiemen]

I bought an old mercury 18hp (don't know the year) and it has problems starting. Usually it starts in idle except after I lift the motor. then I need to start it full throttle. After it starts it will idle and usually restart. Why is this?

 

[Yepblaze]

Re: 18hp mercury problems starting

Because when you lift the motor it spills gas out of the bowls into the throats making it flooded (so to speak) causing you to advance the throttle to make it catch. <br /><br />How's the compression on that motor? If One cylinder is weak it might seem hard to start.<br /><br />Maybe it has some poor grounds and less than perfect ingnition components.<br /><br />Maybe if you took it in and had a good tune up and carb rebuild you'd be more happy with it.

 

[butlp]

Re: 18hp mercury problems starting

The first thing I would do is buy a manual for your motor, available on the web and at this site or from your Merc dealer for about $20.<br /><br />Does the motor run OK above idle? <br /><br />If it had not been used for a long time before you bought it, the carbs are probably gummed up from old fuel. I would systematically work through the fuel system from tank to carbs, strip and clean the carbs (lot's of info on how to do this on this site). <br /><br />I would also check compression and ignition and make sure it is all to spec.(again lot's of info on this site).<br /><br />This should fix the problem.

 

[IndySpecialty]

Re: 18hp mercury problems starting

Sounds like you are unhappy about the # of responses you have gotten by your other thread you started, you didn't even list what year it was to give them an idea of what you have, I have a feeling its OLD very old & might fall under the put it in a wood garage & burn the garage down rule, but if you want to get it running good take it to a dealer & get it tuned up, that motor is so basic that a dealer can have it runnig like a song in a few hours if its got good crank seals & the bores are in good shape. your post is so incomplete there is hardly no chance for anyone to help you. good luck

 

[VanDiemen]

Re: 18hp mercury problems starting

how did you know i'm ugly?? do you know me???<br />just kidding.<br /><br />thanks for the advice. I live in an isolated community with no dealer (fly in access only) so getting it serviced is not possible. it had been sitting around for a while so it might just be gummed up. I'll repost the year once I go to the lake and get my serial number.<br /><br />thanks for the help.

 

[IndySpecialty]

Re: 18hp mercury problems starting

All righty then, Your situation is a little different then most with the remote location, & I'm sure there are a bunch of guys on here that can have that little 18 running like a song if you give them the data they need & the time. Good luck!!