Boat won’t start

[Aaroncooper]

My boat won’t start sounds like it is trying to so I replaced spark plugs and still nothing. So decided to change oil and found this I got water in my oil filter

 

[tpenfield]

Welcome to iBoats and the beginning of cracked block season.

Was the engine winterized? What is the history of this boat/engine?

Perhaps run a compression test?

See how much oil you get out of it and then add new oil/filter and see if it becomes milky again.

Got ignition spark?

Got Fuel?

 

[Aaroncooper]

Had it for 6 years I never winterize it just pull drain plugs bc I keep it in my heated garage. I have not check for spark yet and I’m doing a compression check later today

 

[Aaroncooper]

It’s a 4.3 mercury. Carb engine. It has new battery spark plugs and fresh tank of gas. Sounds weak when trying to start and won’t fully turnover I don’t think the bindex is popping out into the fly wheel.

 

[briangcc]

You were exactly (1) power outage away from a cracked block. **This assumes you do not have a whole house generator.

Did you get lucky?? Oil change will tell the story if it gets milky again.

As for starting it...got your safety lanyard in place?

 

[Aaroncooper]

Yea I checked that. I know it. If I get lucky I’m going to start winterizing it. It was sounding the overheat alarm on the last day of use last summer. I’m hoping it’s only a head gasket or the thermostat but I guess I’ll know if it is a head gasket when my farther in-law checks the compression latter.

 

[briangcc]

Overheat? When's the last time you did the impeller?

 

[Sprig]

Was there water in the oil you drained or was it just around the oil filter? If the oil you drained was milky then you may have a cracked block or blown head gasket. If only around the oil filter it may just be condensation.
What did the spark plugs look like? Were they clean burning? We’re they damp? Have gunk on them? Currently have spark?
Definitely need to do a compression test.
Id be more interested in determining the cause of the milky oil before I worried about getting it to start

 

[TyeeMan]

When you crank the engine using the key, does the engine roll over a full 360 degrees freely? If not, remove all the spark plugs, crank the engine and see if you get any water spraying out of the spark plug holes.
If you are getting water spray out of the spark plug holes you might either have a bad head gasket or a bad exhaust riser gasket that's leaking water back into the cylinders.

 

[Aaroncooper]

I got the boat to start my farther in-law messed around and got all the spark plug sparking and it fired up. We still don’t know about the milky oil it really wasn’t much milky oil when I drained it and none on the dip stick of cap just up in the oil filter. I was thinking maybe it’s my thermostat or a gasket somewhere if it is a gasket on my risers is their anyway to tell by looking or anyway to text the thermostat

 

[Scott Danforth]

oil floats on the water. for that reason I use clear jugs for oil

its usually not a head gasket

since you had an overheat, I would pull the drive to do the annual PM: check alignment, check the gimbal bearing, check the u-joints, and then do a water pump job.

 

[Aaroncooper]

Is it hard to pull the drive or should I let a pro do it

 

[Scott Danforth]

Is it hard to pull the drive or should I let a pro do it

easy. go to the mercruiser forum. top of the forum are the stickies

go to the additional mercruiser information, go down to the videos, and watch the videos. you can also read all the maintenance info in the stickies.

 

[JASinIL2006]

Is it hard to pull the drive or should I let a pro do it

Easy as can be. Here is iboats' very own @achris showing how it's done:

The stickies that Scott referred to are at https://forums.iboats.com/threads/m...diyers-an-work-safe-search-version-of.335378/. It take a while to dig through them and find what you need, but there is a wealth of information in there.

 

[Chris1956]

Water in the oil is bad. It means a leak from either the cracked block or the mainifold gasket. Hopefully the manifold gasket.

Pull the risers and manifolds and lap them with a piece of sandpaper on a piece of glass. Get some Mercury silver gaskets and rebolt them.

Obviously change the oil and run it o the hose for some time to assure it is not longer leaking.

 

[SavinRaven]

overheating.. Hmm I'd do the impeller first before tearing the head off make sure that resolves your overheat issue. May need more pressure on engine then to put it on hose to be sure that's fixed Prolly a lake test to get temp up to operating temp. Let us know what you find in the impeller housing when you take lower unit off.