97 SeaRay 185 with a MerCruiser 4.3 not pumping fuel while cranking

[kmmn]

I have a 97 SeaRay 185 with a MerCruiser 4.3 and an Alpha One Drive. The boat has two problems:
1) Fuel drains out of the carb after sitting for 10-12 hours (I?ve read that that?s an issue with the MercCruiser (Weber?) carbs and that?s not my primary concern (right now).
2) The Fuel Pump does not pump fuel while cranking the engine. (This is the one I?m trying to fix now). I pulled the pump and jumped it to the battery and it engaged immediately and had good pressure. If I bypass the oil pressure safety switch, it will pump and deliver enough fuel to get the motor stated. If I understand it correctly, this is not used at all while cranking, so I don?t think that?s the problem here. (It?s never kicked the engine while running). A voltmeter on the purple (and yellow?) wire coming off of the starter solenoid shows 13-14 volts while the engine is running, but as low was 6 volts during cranking. I would expect a slight drop during cranking, but that much? If that is an excessive drop, then what could cause that? (A bad starter that draws too much current?) A possibly unrelated symptom is the audible alarm when the key is turned is intermittent.

If only one of these problems existed, I doubt I?d notice any problem, but the two together become apparent if the boats sits for 10-12 hours.

Thanks!!!

 

[Silvertip]

Re: 97 SeaRay 185 with a MerCruiser 4.3 not pumping fuel while cranking

The oil pressure switch should be bypassed by the solenoid when the key is turned to START. Without this feature, the pump can't run, the carb can't be filled, and the engine won't start until oil pressure builds which trips the oil pressure switch.

 

[Bondo]

Re: 97 SeaRay 185 with a MerCruiser 4.3 not pumping fuel while cranking

2) The Fuel Pump does not pump fuel while cranking the engine. (This is the one I’m trying to fix now). I pulled the pump and jumped it to the battery and it engaged immediately and had good pressure. If I bypass the oil pressure safety switch, it will pump and deliver enough fuel to get the motor stated. If I understand it correctly, this is not used at all while cranking, so I don’t think that’s the problem here. (It’s never kicked the engine while running). A voltmeter on the purple (and yellow?) wire coming off of the starter solenoid shows 13-14 volts while the engine is running, but as low was 6 volts during cranking. I would expect a slight drop during cranking, but that much? If that is an excessive drop, then what could cause that? (A bad starter that draws too much current?) A possibly unrelated symptom is the audible alarm when the key is turned is intermittent.

Ayuh,... Welcome Aboard,.... I'd sooner think bad, or corroded wirin' connections...

Pull, clean to shiny metal, reinstall, 'n grease All the startin' circuit wirin' ends,.... startin' at the battery...

Includin' the Grounds, 'n don't forget, wires have 2 ends....

 

[kmmn]

Re: 97 SeaRay 185 with a MerCruiser 4.3 not pumping fuel while cranking

I'm with you on the bad connection, but (and I should have been clearer about this) when I said the voltage drops, I'm actually testing at the lug on the starter solenoid, so I may have a bad connection somewhere, but that's not the cause for the voltage drop.

 

[Don S]

Re: 97 SeaRay 185 with a MerCruiser 4.3 not pumping fuel while cranking

Is the purple yellow wire hooked to the outboard small terminal on the starter solenoid?

 

[Bondo]

Re: 97 SeaRay 185 with a MerCruiser 4.3 not pumping fuel while cranking

I'm with you on the bad connection, but (and I should have been clearer about this) when I said the voltage drops, I'm actually testing at the lug on the starter solenoid, so I may have a bad connection somewhere, but that's not the cause for the voltage drop.

Ayuh,.... Bad connections can cause voltage drops, under extreme loads, like startin',....

'ell,... a Bad Ground can do that...

 

[kmmn]

Re: 97 SeaRay 185 with a MerCruiser 4.3 not pumping fuel while cranking

Is the purple yellow wire hooked to the outboard small terminal on the starter solenoid?

exactly