merc 25 4 stroke hard to start

[jason011]

my ol man has a 2001 or 2002 25hp merc 4 stroke on the back of his pontoon boat, it worked a 1 last year and this year it is very hard to start, its not fuel injected, i told him i would replace the fuel pump on it, clean the carb and put a new set of plugs in it, im lookin for any feedback or other ideas, i just want to save him a little money before he burns his starter out tryin to start it....... he wont listen when i tell him to stop using it cause theres obviously something wrong with it, now that i think about it, it was pretty cold blooded last year but nothing even close to now, you would almost think the battery is gonna go dead by the time it actually starts....... if i could get some quick feedback, that would be great........ i have a sneaking suspision that hes gonna hook on and head to lake in the next few days, id like to get it fixed before he does that and ruins other parts and makes my job alot harder thanks

 

[1nebel0]

Re: merc 25 4 stroke hard to start

The first thing is to check for spark...it obviously won't start without spark...If you have spark you have a fuel problem...These motors have a problem with the plastic float being ruined by ethanol...if you smell fuel then you have a float problem and has to be replaced..Thank you Ethanol for all the things you ruin.....keep us posted..........

 

[jason011]

Re: merc 25 4 stroke hard to start

well....... i got him a primer bulb for the motor, he took it out and tried it and said it was a little better than before but it still takes alot of cranking to get it to start, before all of that, i unhooked his fuel line ( after the pump ) pumped the bulb and gas shot out about 5" then i hit the key and fuel flew out about a foot or better, it has fire....... once you start it it runs perfect, i just dont want him to ruin his starter trying to get it going, while i had the carb apart i noticed the needle valve was a little marked up on one side but i cant see that making much difference ( the rubber part is still like new ), any opinions??, wonder if it would make any difference if i index the plugs???

 

[jason011]

Re: merc 25 4 stroke hard to start

sorry it took so long to get back.... the ol man had a tripple bypass but the problem ended up being a little plunger in the bottom of the carb was stuck, got it freed up and replaced it and it starts with a bump of the key