Round water proof deck plate on tritoon

[Gumboot]

If it were actually watertight I wouldn't be writing this.  There's an 8" round screw in "deck plate" that accesses a bilge pump in the rear of the center log on my wife's tritoon that leaks.  The bilge pump has quit working, but that's another issue that I'll have to deal with this winter.  Why you'd cut a hole in a log to start with is beyond me.  It looks like the picture below.  Are there better ones that don't leak.  The one she has has a very small O ring that apparently has failed with age.

[Terrierman]

Permatex form a gasket will solve your problem.

[Gumboot]

38 minutes ago, Terrierman said:

Permatex form a gasket will solve your problem.

If I put Permatex on the threads would I be able to back that thing out again?  Asking cause there's a bilge pump directly beneath this cover.

[Terrierman]

1 hour ago, Gumboot said:

If I put Permatex on the threads would I be able to back that thing out again?  Asking cause there's a bilge pump directly beneath this cover.

Sure will.  It's just high grade silicone.

[Gumboot]

Thanks, I'll give it a try.

[fishinwrench]

46 minutes ago, Terrierman said:

Sure will.  It's just high grade silicone.

Um, no it isn't.  Permatex aviation form-a-gasket is for sealing machined metal to metal components like crankcases, or for using as a gasket sealer, or as a light thread locker to prevent bolts from vibrating loose. 

Your leak is probably coming from the flange, and not from the screw in cap.  But either way some RTV sealant will stop the leak.  

You don't want form-a-gasket on that thing..... it's sticky messy crap that even the best of hand cleaners won't wash off.   And it will lock those plastic threads up tighter than a pelicans @$$

[Gumboot]

Ok.  You guys got me confused.  Here's a pic of the cap that my wife took at the lake today, as I sit at my desk working.  It's the white cap in front of the motor.

[fishinwrench]

Remove the 6 screws holding the flange down, clean up both surfaces and put a bead of clear RTV around the flange and screw it back down.   

The O-ring on the cap....if it is damaged replace it.  If it isn't damaged then just smear a light coating of grease on it.  

Or just replace the whole assembly.....they run 9.00-14.00

[Gumboot]

15 minutes ago, fishinwrench said:

Remove the 6 screws holding the flange down, clean up both surfaces and put a bead of clear RTV around the flange and screw it back down.   

The O-ring on the cap....if it is damaged replace it.  If it isn't damaged then just smear a light coating of grease on it.  

Or just replace the whole assembly.....they run 9.00-14.00

OK.  I can handle that.  While your in a giving mood... what spark plugs does my 2003 90 hp Yamaha take?

[fishinwrench]

1 hour ago, Gumboot said:

OK.  I can handle that.  While your in a giving mood... what spark plugs does my 2003 90 hp Yamaha take?

There is a sticker under the cowling that tells you the correct plug and its appropriate gap.  

2-stroke 90 is NGK BR8HS-10  gap=.040

4-stroke 90 is NGK LFR5A-11 gap=.044