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vermin
15-10-2005, 11:47 AM
After running my outboard at home in a bin full of water for about 5 minutes I notice that the leg of the ouboard very hot. Not far off the "too hot to touch" mark. Similar to a hot mug of coffee ...

Is this normal?

Outboard is a Yamaha 50 2 stroke.

Thanks,

Geoff.

darryl_l
15-10-2005, 11:53 AM
Vermin,

After only five minutes of running your motor it should not even have reached working temperature yet. Was there a good stream of water from the teltale? Did you have the motor in gear or neutral? Were you running at revs or at idle?
Did it seem hot at the top of the leg or where it entered the water?

Darryl L

vermin
15-10-2005, 12:48 PM
Darryl,

It got hot pretty quick. It was in neutral at idle and there was a good stream from the teltale. I'm going to run it again soon to time everything.

The hottest part seemed to be in the middle of the leg.

Thanks,

Geoff.

FNQCairns
15-10-2005, 01:27 PM
Yeah they do get warm, the exhaust gasses travel through there on the way to the prop. Next run you do, feel the leg straight after it can get very very warm.

I can only assume on the muffs a lesser volume of water gets to exit with the gasses but at idle this is no problem.

cheers fnq

vermin
15-10-2005, 01:35 PM
I done another run once it cooled off. Yes the heat seems to come from top down. Bottom of the leg is only warm where the top half is very very hot. Got this hot in 3 minutes. The leg is still submerged (not muffs). Plenty of pressure from the teltale.

I recently had it serviced and they commented that the motor ran very well (so it should I supposed for a 2003 model). Maybe worth another call to the machanic just to be sure :-/. They are a reputable company.

Big_Kev
16-10-2005, 06:43 AM
I think it sounds normal, any motor I have ever had gets hot at the leg when running in the drum.
This is where the exhaust is and having it in the drum creates back pressure in the exhaust. When using muffs there is no pressure.
Coolant does exit with the exhaust to keep it cool.
If you can put your hand on the leg for only a second and then have to pull it away the surface temp of the leg will only be around 60 degrees C.
But it would be a good idea to show you mechanic. :)

vermin
16-10-2005, 09:53 AM
Thanks Reel Hard ... I think she'll be fine but I'll give them a call tomorrow. Might run it on the muffs today to see if there is much difference.

vermin
18-10-2005, 02:45 PM
Took the motor into the mechanics today and was given a clean bill of health. Within the limits they say.

Thanks to everyone for their input.

Cheers,

Geoff.

Fishin_Dan
18-10-2005, 04:15 PM
Is the water in the barrell warming up? Maybe the exhaust gases are warming up the water, so the water that then gets pumped through the motor is not cold... Each cycle would warm up more and more...?