How hot can upper gearbox be when running on muffs? Pre-alpha drive..

[-stig-]

as topic, was running my 140hk merc on muffs today, and the upper box became a little hot, maybe 35degree celsius, is that normal?

regards,stig

 

[Bondo]

Re: How hot can upper gearbox be when running on muffs? Pre-alpha drive..

Ayuh,... Is it Full of oil,..??

How long did it run,..??

How hot is 35?C,..??

 

[nikon]

Re: How hot can upper gearbox be when running on muffs? Pre-alpha drive..

Pretty normal. Run your boat on plane for a few minutes, then touch the upper gear box...you'd be amazed how hot it gets.

 

[wca_tim]

Re: How hot can upper gearbox be when running on muffs? Pre-alpha drive..

assuming you've got the exuats running out the prop, the exhaust gasses do a nice job of heating the drive! A lot more so than most people realize...

 

[paultjohnson]

Re: How hot can upper gearbox be when running on muffs? Pre-alpha drive..

Ayuh,... Is it Full of oil,..??

How long did it run,..??

How hot is 35?C,..??

35 C = 95 F Water freezes at 0 C and boils at 100 C [at sea level] Skipper...

 

[HT32BSX115]

Re: How hot can upper gearbox be when running on muffs? Pre-alpha drive..

as topic, was running my 140hk merc on muffs today, and the upper box became a little hot, maybe 35degree celsius, is that normal?

regards,stig

It would depend on hot the "lower" got.....(due to exhaust temps)

If you only ran it for several minutes, and at idle, It should not get very hot at all. (the gears are unloaded with the prop out of water)

 

[-stig-]

Re: How hot can upper gearbox be when running on muffs? Pre-alpha drive..

thanks for the replies so far!

exhaust out the drive, ran it for maybe 2x15minutes with a little check in the middle. ran at various revs, from idle to 2500-3000rpm.

bottom end of the drive was cool, a little higher temperature in the middle section and a bit hotter on the upper.

just changed the bearings in the upper gearbox, and new oil!

never checked the temperature on the drive before, and was a bit supriced, that hot with no load..

 

[nikon]

Re: How hot can upper gearbox be when running on muffs? Pre-alpha drive..

just fyi, don't think your supposed to rev the engine that high on muffs.

 

[-stig-]

Re: How hot can upper gearbox be when running on muffs? Pre-alpha drive..

does anyone got a clue?

 

[elkhunter338]

Re: How hot can upper gearbox be when running on muffs? Pre-alpha drive..

I noticed the same thing with my outdrive a few weeks ago. SEI just rebuild the upper part due to a oil seal leak (not caused by sei, water leaked in to the bellows and rusted the shaft, caused seal to leak oil into the bellows).
Well the rebuild drive was warm to the touch, warmer than I thought it should be but I assumed it was because of exhaust temp.
I fully warmed the engine and ran it for 15 min or so.
I rev mine up to 2500 or so with full water flow on the muffs, but I make sure the hose is still supplying enough h20. you run the risk at higher rpms of collopasing the garden hose and burning up the water pump.
I go for sea trials soon, hope the drive holds together and everything is fine.

 

[HT32BSX115]

Re: How hot can upper gearbox be when running on muffs? Pre-alpha drive..

just changed the bearings in the upper gearbox, and new oil!

all in accordance with the service manual right?

 

[-stig-]

Re: How hot can upper gearbox be when running on muffs? Pre-alpha drive..

Yep, followed the manual step by step! first time, but no big deal!