Why is my outboard leaking fuel

[ithet]

An old thread I know, but I have the same issue with my mariner 3.3hp whereby the cap leaks if tilted too far, I just need the rubber insert, does anyone know a source or part number? I don't really want to buy the plastic cap for £35 just for the rubber insert.

My friend had a similar problem but it was turned out not to be the cap seal. There was a hairline crack around the top of the tank threads for the cap - only visible by applying a gentle bending force to the filler neck which opened the gap a little. Probably due to over tightening the cap.

 

[Scubadoo]

It is listed as a separate part but is "unavailable"

Thanks, where did you find that information, I can't seem to find the separate part.

 

[Scubadoo]

My friend had a similar problem but it was turned out not to be the cap seal. There was a hairline crack around the top of the tank threads for the cap - only visible by applying a gentle bending force to the filler neck which opened the gap a little. Probably due to over tightening the cap.

That is very helpful info, I will double check, thank you.

 

[chrishscorp]

Yep Mariner 3.3 only have a problem if the tank is filled up i know why now, i will check the rubber washer. Somebody will do a washer somewhere.....

 

[Scubadoo]

Yep Mariner 3.3 only have a problem if the tank is filled up i know why now, i will check the rubber washer. Somebody will do a washer somewhere.....

Trouble is, mine is not stored upright, on its front, for many years well must be 15+ never leaked. So now I don't fill it too much until I can get it sorted.

If I can't get the rubber insert, I will consider making a Cork gasket.

 

[scottie]

You know the answer. Don't procrastinate.
[/QUOT

 

[Jamie Dundee]

My friend had a similar problem but it was turned out not to be the cap seal. There was a hairline crack around the top of the tank threads for the cap - only visible by applying a gentle bending force to the filler neck which opened the gap a little. Probably due to over tightening the cap.

I’ve just bought a 4t 2010 Tohatsu 3.5 with “a leaky cap seal” as the vendor described it. After much faffing it turns out the filler neck is badly split, can’t think how. A new tank and cap on the way via eBay, £80. My bargain £250 motor just got expensive