Mercruiser 3.0L 4cyl starting and idling problem... longer than usual and hesitates

[thecca]

Hi there, I just bought a Maxum 1800 SR boat (year 2000) and it came with the mercruiser 3.0L motor.

I noticed yesterday that the boat had trouble starting (it takes about 10-15 shots of cranking before it starts and it has trouble idling after (it dies))

BUT when the forward gear is engaged, the motor runs A1 and is really smooth... As soon as I put it back in neutral, it dies within 30 seconds.

Yesterday I got stock on the river for about an hour, the motor wasn't firing but I really felt like it was trying.

The previous owner bought and installed a new carb (Reman Carb part no.804617R) + Quicksilver shift cable + new oil everywhere + thermostat housing + exhaust manifold +spark plugs + fuel filter + distributor cap and rotor in last february.

Basically, the maintenance was done, but it's still dying? I thought the problem would be gone after a good ride but it's still there...

Anyone can help? It's really embarassing.

 

[airshot]

Re: Mercruiser 3.0L 4cyl starting and idling problem... longer than usual and hesitat

Have you adjusted the enrichment screw while at idle in neutral? Also has the shift interuptor system been tampered with? If the new cable did not include a proper adjustment the interupter switch may be out of sinc. A "mercruiser" service manual will be needed to get the proper adjustment for the cable/interuptor switch, and yes it is tricky to get it just right.

 

[thecca]

Re: Mercruiser 3.0L 4cyl starting and idling problem... longer than usual and hesitat

Have you adjusted the enrichment screw while at idle in neutral? Also has the shift interuptor system been tampered with? If the new cable did not include a proper adjustment the interupter switch may be out of sinc. A "mercruiser" service manual will be needed to get the proper adjustment for the cable/interuptor switch, and yes it is tricky to get it just right.

No I didn't. What do you mean ''tampered with''? (Sorry, english is my 2nd language). I'm pretty new to boats but I have a few basic knowledges about mecanic so I think I might be able to do it myself... The previous owner gave me the ''Clymer Mercruiser'' stern drive shop manual. I'll take a look at it!

 

[thecca]

Re: Mercruiser 3.0L 4cyl starting and idling problem... longer than usual and hesitat

Anyone has other suggestions??

 

[thecca]

Re: Mercruiser 3.0L 4cyl starting and idling problem... longer than usual and hesitat

UPDATE : I adjusted the carb (idle mixture screw + idle screw) and the ignition timing and it seem to work a lot better!

I'm starting to think that it's the float, even if the carb was changed in february (for a remanufactured one)...? I've noticed the carb was getting a lot of gaz (it's dripping when I turn off the motor). So I think the float can be bad AKA stuck in open position and flods everything so the motor has trouble to start after being shut down?

On coldstart, it starts right up after 2 shots of crank. (Probably because there's no gaz accumulated in the carb?)

Also, I set the idle to 900 rpm (instead of 600 as recommended) so it don't stall anymore, but I don't think it's correct, since the motor should be running fine idling at 600rpm (probably again because there's too much gaz pouring in on idle? But the idle mixture screw was set correctly...)