cowl air inlet on mercury 9.9.

[billhig]

I've got a 1979 9.9 2 stroke and I don't see where the air inlet into the cowl is. The top cowl is completely sealed and the only gap in the lower cowl is a finder width opening around the shift shaft. It doesn't look very big. Am I missing something obvious?

 

[racerone]

Would that be a 9.8 model?----Serial # is ?

 

[airshot]

Usually in the rear of the cover, made to be a lift handle for tilting the motor.
They also act as an air opening if you look carefully.

 

[billhig]

Usually in the rear of the cover, made to be a lift handle for tilting the motor.
They also act as an air opening if you look carefully.

The lift handle is sealed.

 

[billhig]

Would that be a 9.8 model?----Serial # is ?

Sorry, typo 1999 9.9, serial number OG889354

 

[airshot]

The lift handle is sealed.

That would be a first for me, never saw one sealed. Did you check from the inside ?

 

[flyingscott]

It is in the rear of the cowl by the grab handle. Or are you saying it does not run with the hood on?

 

[billhig]

It is in the rear of the cowl by the grab handle. Or are you saying it does not run with the hood on?

It runs poory at WOT with the cowl on. It runs smoother and goes faster with it off. I have read that can be caused by an exhaust leak so I just pulled the powerhead and replaced the exhaust gasket. TBD if it helps.
The cowl is completely sealed at the grab handle by the part shown in the pics. The hole in the front of the cowl is sealed by the rubber piece around the starter pull. The only opening is down by where the shift shaft comes in but that's pretty small.

 

[cyclops222]

My old Evinrudes look like they have no breathing opening. They have gaps around the bottom of the cowling to keep water & spray out of engine parts.

 

[airshot]

Where the grab handle is located, there should be an intake up near the top so water can't get in. Can be hard to see, check for wasp/bees nests there. Blow air up into the area and you should feel air moving. It could be possible that it became blocked somehow, but that is where all have been in my outboards.

 

[billhig]

Where the grab handle is located, there should be an intake up near the top so water can't get in. Can be hard to see, check for wasp/bees nests there. Blow air up into the area and you should feel air moving. It could be possible that it became blocked somehow, but that is where all have been in my outboa

Where the grab handle is located, there should be an intake up near the top so water can't get in. Can be hard to see, check for wasp/bees nests there. Blow air up into the area and you should feel air moving. It could be possible that it became blocked somehow, but that is where all have been in my outboards.

As shown in the pics, the grab handle is completely sealed. That's why I'm confused.

 

[cyclops222]

Well I am feeling great with my medical cup of Caffeine. So I will go to the boat and see if there is a removable part in the cowl / cover. Take it out. 2 strokes are noisey already.

NAAAAH It is a fantastic reliable engine since 1986. I will respect it's age and retirement duty.
If it is not broken. I will not fix it.

 

[Chris1956]

Exhaust leaks are often caused by the powerhead base gasket.

 

[billhig]

Well I am feeling great with my medical cup of Caffeine. So I will go to the boat and see if there is a removable part in the cowl / cover. Take it out. 2 strokes are noisey already.

NAAAAH It is a fantastic reliable engine since 1986. I will respect it's age and retirement duty.
If it is not broken. I will not fix it.

Great minds think alike - I took out the grab handle insert and now I've got a huge inlet. I'm still confused as to why there is none to begin with but that's a reasonable solution. However, that had no impact on the boat running poorly at WOT with the cowl on.

 

[billhig]

Exhaust leaks are often caused by the powerhead base gasket.

Yes, I knew that. I replaced the gasket from the powerhead to the adapter plate and the gasket from the adapter plate to the mid-section. Still acts the same. I'm running out of ideas but I'm gonna change out the plug wires as they get close to the cowl. they are probably 20 years old.

 

[airshot]

Is there a CDI control box ? When these go bad, often it is the high speed that goes haywire.

 

[cyclops222]

Dying... Fuel pump ? sparkplugs ? loose / worn throttle linkage / Linkage rubbing on something with cover in place ? pinched fuel line by cover ?

Or a little of all ?

 

[billhig]

Dying... Fuel pump ? sparkplugs ? loose / worn throttle linkage / Linkage rubbing on something with cover in place ? pinched fuel line by cover ?

Or a little of all ?

Fuel pump and carb rebuilt. New plugs. Cowl doesn't touch anything when on.

 

[billhig]

Is there a CDI control box ? When these go bad, often it is the high speed that goes haywire.

It does have CDI but why only when the cowl is on.

 

[airshot]

So....the motor runs fine without the cowl on ?