Mercury 40 not starting

[ajwolfe23]

Posting for my hubby, so bare with me.

We have an older 40hp oil injected motor that was running perfectly on Saturday when we took it out of storage. Put in new fuel & fired right up, ran all day with no problems. Sunday morning, it won’t start. It has spark, has fuel & has compression. Wouldn’t start in the water, continues to not start in the driveway. Cranks & cranks, but won’t fire. Any suggestions on what to check?

 

[IslandExplorer]

Posting for my hubby, so bare with me.

We have an older 40hp oil injected motor that was running perfectly on Saturday when we took it out of storage. Put in new fuel & fired right up, ran all day with no problems. Sunday morning, it won’t start. It has spark, has fuel & has compression. Wouldn’t start in the water, continues to not start in the driveway. Cranks & cranks, but won’t fire. Any suggestions on what to check?

Hello, I have a few ideas for ya:
Check man overboard kill switch. (Usually red lanyard hanging near controls somewhere, connects to kill button) These tend to kill ignition circuit randomly sometimes when they get wet if they are cracked/failing. Check engine wiring harness for obvious frays or pinched wires possibly grounding out. Check plugs after cranking and see if wet with gas. If not- fuel is being stopped somehow. Pump primer ball to see if this cures no start. If so then fuel flow is issue. If plugs wet then ignition is not working consistently. Need to narrow it down to fuel or spark if compression is definitely good. Also make sure battery is good, fully charged, and terminals clean. Weak battery can spin motor but sometimes not fast enough to start it. Some fuel hose quick connects notoriously crack their seal and allow air to suck into fuel system, while also concealing the leak. This can kill your fuel flow and stop engine starting. Hopefully one of these suggestions is of some help and gets ya started again!

 

[jimmbo]

Welcome to iboats

You say it has Spark. I the Spark strong enough to jump a 7/16" gap?

 

[racerone]

Stop cranking and cranking , it is easy to destroy the starter.----Do some testing.----Post the actual compression numbers.-----Oil injection system tested and working properly.----Serial # of your motor.