2003 Mariner 5hp 4stroke drive loss

[squirty34]

Hello.

I have a cranky engine inherited. After a thorough clean of carb and fuel systems the engine now runs.

BUT.

On full power it suddenly looses drive for 30 seconds, the boat stops and then it starts again on lower power.

Anyone know what is going on?

Mystified.

Andy

[SV Bacchus]

Sounds like fuel supply. Checked the vent on the tank, is it open? Fuel line not kinked or pinholes? Just a WAG.

Always best to start with the simple things.

[squirty34]

No the engine is still going full speed. It is a drive issue somewhere

[Charlie]

Does it have a centrifical clutch? If so perhaps that is sticking and needs to be cleaned. If not the drive systems are pretty simple and may need a cleaning. Good luck.

[Cadence]

Originally Posted by squirty34

Hello.

I have a cranky engine inherited. After a thorough clean of carb and fuel systems the engine now runs.

BUT.

On full power it suddenly looses drive for 30 seconds, the boat stops and then it starts again on lower power.

Anyone know what is going on?

Mystified.

Andy

The cheap prop they use has broken loose from its rubber hub.

[01kiwijohn]

check the shear pin, on the prop shaft

[squirty34]

Thank you. Where is the shear pin? Sorry to be clueless.

[Cadence]

Originally Posted by 01kiwijohn

check the shear pin, on the prop shaft

Shear pin? You must be as old as me.

[01kiwijohn]

On those small, older, Mariners, the prop is held on either with a split pin, or a nut. Remove the split pin, pull the prop and there should be a small pin that goes thru a hole in the shaft, each end protruding into a recess in the prop. I have "salvaged a couple of these type of drives that the owners had given up on.
Now, if you take a look and see that there is a synthetic rubber bushing, inside the prop hub, that's another story. New prop is the only real fix. (I recently had this happen on a customers' out-drive boat, so we just motored to a nearby marina, at just above idle. A slow, but not unsafe trip).

[squirty34]

Thank you. It did have Split pin and a nut when I took it off a couple of days ago. I didn't notice any other pin just splines which did not look worn. I didn't notice rubber either but I wasn't looking for either. Will take apart again and see.

[a64pilot]

You can actually have the hub replaced, but on a little motor it may not be worth it, a whole prop may be just about as cheap

[Cadence]

Originally Posted by squirty34

Thank you. It did have Split pin and a nut when I took it off a couple of days ago. I didn't notice any other pin just splines which did not look worn. I didn't notice rubber either but I wasn't looking for either. Will take apart again and see.

I am afraid the answer is a new prop. I have had that with a 9.9 Mariner. I'm guessing they were still using a cheap "plastic" prop with a rubber hub on what you have. Buy a real prop. not that same thing. It will cost a little more but only once.