Seagull gearbox

[Frank mellin]

Have just drained the gearbox on my seagull 40 +and all that came out was water!
Have refilled with 140 oil and no apparent leaks at moment but is there a seal that has failed allowing water in?

 

[jamie N]

I can't answer your question, but was it 'clean' water, or rusty water, and does it still turn? I'd suggest that it's more likely to illustrate if it leaks when turning, but I'm certainly not an expert!
Good luck.
I do believe though that there's a guy in this parish whose website is Save our Seagulls, or similar, plus many others, such as Tranona, who I think have great experience on these motors.

 

[Tranona]

Depends on which gearbox it is. Pre 1980 without clutch have no seals, just bronze bearings and heavy oil. So mixture of oil and water quite common. Post 1980 has a seal on the propshaft.

 

[AntarcticPilot]

My understanding is that they are intended to work on an emulsion of water and oil, which provides cooling.

 

[Tranona]

Yes, sort of. The original lubricant (forget the exact grade) was more like grease and id mix with water. Cooling was not really a problem with the original big slow turning gears. The move to seals was necessary because the new gearboxes were smaller and the clutches and FNR gearsets had sliding shafts. A lighter oil could be used - the old stuff was getting difficult to source. Big bonus for users was the major sources of oily drips was stopped.

 

[andsarkit]

SAE 140 is correct. Some water in the oil is usual and does not seem to cause problems.
Try running it for a while and check the oil again. If the oil is leaking out it should be visible when the motor is stored upright. On the water it may be masked by the oil slick from the oil in the 2 stroke mix if you are still using 10:1 mix.
I do like the simplicity of my old seagull and should get it out for another run as its been sat in the garage for a few years now.