Mercruiser 3.0 won't start??

[gwgautney]

Ok so I bought another boat. Its a 16'Wellcraft with a 3.0. It needs a Gimbal bearing(thats going to be another thread) but motor turns over good and will fire when starter fluid or gas is put into carb. My question is where should I start first in trying to figure out why it's not getting fuel. It has been sitting for the last 6 months according to the previous owner.

Thanks
Gwgautney
Roll Tide

 

[eavega]

Re: Mercruiser 3.0 won't start??

I'm sure first thing folks are going to ask is that you provide serial number so we know which 3.0 we are talking about.

In lieu of knowledge of the actual motor, the KISS principle would tell me to check the fuel filters first, as that is easy enough to inspect.

After that, work your way backwards from the carburetors, through the fuel pump, and into your fuel tank looking for a restriction.

You could be looking at anything from a stuck needle valve to kinked fuel line, to a bad fuel pump to a bad pickup in the tank.

Good luck.

Rgds

Eric

 

[gwgautney]

Re: Mercruiser 3.0 won't start??

My SN is A432716 how do i find info out on this sn
also my drive unit sn is a377815 and transom plate is a362232
any info on these would be helplful or where i can find them

 

[achris]

Re: Mercruiser 3.0 won't start??

My SN is A432716 how do i find info out on this sn

The serial number is all we need. That gives us direct access to the information we need to help you. Or ask the right questions.

From that I know you have a 1985 engine, model # 01409005. That engine came with a few different components for fuel and ignition system.

The carb could be either a Mercarb or a Rochester. The easiest way to distinguish them is to look at the base of the carb. One idle mixture screw=Mercarb, two idle mixture screws=Rochester.

That engine also could have a points distributor, or a stange looking coil with 4 leads, each going to a spark plug of its own, called a DDIS (Digital Distributorless Ignition System)....

It could also have one of 5 different alternators, one of 2 Delco-Remy, 2 Motorola or a Mando....

So, whenever you start a new thread and ask question about various components, post up the serial number what you have, if it's pertinent. You'll also find a serial number on the drive, different to the engine, post that when you ask drive questions.

I find the easiest was to diagnose is to split things. So at the moment you know you have no fuel getting to the combustion chambers. But everything else seems ok (for the moment)... I would disconnect the fuel line from the carb (or fuel pump) and crank the engine. If you have fuel coming out, then the problem is in the carb. If you don't, you have a supply problem.... Just keep splitting the area, and eventually (and quite quickly) you'll find the problem.

Chris......
(now you know my secret )

 

[eavega]

Re: Mercruiser 3.0 won't start??

Just keep splitting the area, and eventually (and quite quickly) you'll find the problem.

Chris......
(now you know my secret )

Answer to the age old question; How do you eat an elephant? One bite at a time!

Rgds

Eric

 

[achris]

Re: Mercruiser 3.0 won't start??

Just keep splitting the area, and eventually (and quite quickly) you'll find the problem.

Chris......
(now you know my secret )

Answer to the age old question; How do you eat an elephant? One bite at a time!

Rgds

Eric

Indeed....

 

[gwgautney]

Re: Mercruiser 3.0 won't start??

Ok pump appears to be working fine getting fuel to carb. Where do I need to go from here? Also it is a mercarb one idle screw

 

[achris]

Re: Mercruiser 3.0 won't start??

Pull the carb, strip it down, soak all the non rubber parts in carb cleaner overnight, then blow it all out with DRY compressed air (all the passages and drilling, not just the outside) and reassembly with a new gasket kit, checking the adjustments along the way... Do you have the manual?

If you don't feel confident stripping the carb yourself. Just remove it from the engine and take it to a carb shop....

Chris......

 

[gwgautney]

Re: Mercruiser 3.0 won't start??

Update dont know what i did but shes a roaring. got it cranked this evening. may have been the bad gas i syphoned the tank put in new but it still wouldn't crank may have just taken awhile to work any of the old out. thanks for all the help just for say what does it run normally for a carb rebuild??

 

[achris]

Re: Mercruiser 3.0 won't start??

... thanks for all the help just for say what does it run normally for a carb rebuild??

Yep, could have just needed the prime... As for the cost of a re-build? No idea, always done them myself.

 

[gwgautney]

Re: Mercruiser 3.0 won't start??

Got back out on motor next day and wouldn't start again. Somebody had jb welded the body where choke is. I was fooling with it and broke it again when I did that I guess it freed up choke and she cranked up. Do they sell just top part of carb so I don't have to replace complete carb

 

[achris]

Re: Mercruiser 3.0 won't start??

Got back out on motor next day and wouldn't start again. Somebody had jb welded the body where choke is. I was fooling with it and broke it again when I did that I guess it freed up choke and she cranked up. Do they sell just top part of carb so I don't have to replace complete carb

That should be a TKS (Turn-Key Start) carb, and there is no part number on the parts breakdown for the top section...

A lot of people, when a TKS carb fails, just throw on a 'normal' Mercarb for the 3 litre. Have a look HERE.

Chris........