Burnt Alpha One Gear Oil Thoughts

[andrewterri]

When I did the oil change on a Alpha 1 Gen 2 I noticed the oil had a very burnt smell. The color was good and no water intrusion. I recognized the burnt smell, 1. because it is not normal, 2. we have two seadoos and when we change the jet pump oil if the kids ride hard all summer it will have that burnt smell. The boat only had 19 hrs due to lake flooding the year before. Any thoughts why the oil would break down so fast? Maybe from a lot of hole shots? We spent most of our time at the beach so there is a lot of trips from the marina to the beach and back. About a 2-3 min drive.

 

[alldodge]

Not understanding the burnt smell either with no issues. The Alpha runs fairly cool if full. Was the lube a tad low?

 

[achris]

What engine is in front of it? What are you pulling at WOT (rpm)? What size prop (pitch, in inches) are you running?

Chris.......

 

[racerone]

Even new gear oil has an awful smell to it.

 

[harringtondav]

My gear lube apparently "went bad" with low hrs. I take the blame. I doubt if we accumulated 5-10 hrs/year for two years each due to other projects, etc. I'd crack the drain to check for free or emulsified water, and tighten it back up.

When I finally drained the lube it stank to high heaven, and was jet black. I know animal and vegetable fats and oils can go rancid/septic, so I assumed my lube did the same. ...Now I'm back to annual lube changes regardless of the hours.

 

[racerone]

A lot of good gear oil is thrown out.-------Oil is cheap they say.------Fact even good outboard gear oil does smell bad !

 

[QBhoy]

One of the things that might do this is running for too long on the trailer with high rpm. Perhaps extreme but a possibility.
what gear oil was in it, if you know at all perhaps.

 

[andrewterri]

I am not pulling anything at high RPM. Really only one full day of tubing on the oil. Don't spend much time driving around pulling things because the 4 year old will start getting anxious. It is in front of a 4.3 mpi ec. The year before it never burnt like that. The boat does not run over 3400 rpm. Only time it gets to wot is during prop selection and once last year to out run a storm coming in. I was curious as to what everyones thoughts were with such low hours. During the change the fill bottle is always emptied before draining. The oil in the bottle was fine it was the oil in the drive that had the horrible burnt smell.

 

[andrewterri]

During normal years (without losing half the summer from flooding) I normally do a mid season oil change for engine and drive. We normally run the boat alot and about half way through summer the oil really starts to darken up. When in doubt I have always went with the saying, oil is cheap-engines are expensive.

 

[achris]

Just because you don't often go WOT doesn't mean you can't be over-propped. If the prop is too big (too much pitch for the engine to reach the recommended rpm at WOT), then it's too big for the entire rev range, not just WOT....

Still don't know the size of the prop....

Chris........

 

[andrewterri]

14.5X17 4 blade. Prop is slightly under propped. Hits 4800 and slowly climbs to near 5000 when I shut it down. That is fully loaded and I just did it today. Ordering a stainless prop so I checked it today to make sure I didnt need to drop down to 15p since the kids have grown in the last 3 years since buying and testing current prop. I can always just change the gear lube more frequently since I must be doing something to burn the oil.

 

[racerone]

New water pump impeller put in recently ?

 

[TyeeMan]

I had this same thing the year before last. Same drive but behind a 5.7L. It was lower boat usage year, I don't pull skiers or tubes, strictly fishing or cruising.
I dropped the drove oil at the end of that year and it had that sulfur/burned smell. A little darker than normal but not black by any means. Drive oil was full, , if I can trust the gear oil monitor.
Yeah, it was the strangest thing. Gear oil is, as always, Amsoil synthetic marine gear oil.
Dropped the gear oil at the end of last year and it was just like it "normal", pretty clear and no smell.

 

[andrewterri]

I put a new impeller in last year. I have been using mer's HP stuff. I am going to watch it and do a mid season change and see what its like. Tyeeman, it must have something to do with periodic use and short runs as that is what we did. Thank you guys for your thoughts. With all this time at home during quarantine it has me pondering things like, "why did my gear oil burn with only 19 hrs" :lol:

 

[racerone]

I do not believe your gear oil is " burning " on you.

 

[andrewterri]

I call it burning because it has that burnt smell. You are right racerone, I do not believe it is burning. I do not know what else to call it other than saying it has a burnt smell or bad odor.

 

[achris]

The usual reason for oil getting worn/burnt prematurally is over-propping (which increases the shear load on the oil), but you appear to not be over-propped.

Had the oil you used been sitting for a long time? If so, did you give the container a good shake before using the oil?

Chris..........

 

[andrewterri]

It was likely sitting for a long time. It came from Walmart and had dust on the top. Our Walmart is in a smaller town so that's not unusual. I did not shake the bottle other than bringing it home and sitting it on a shelf until I used it.

I am very aware and worried about being over propped. I do not want to trash my engine. And check at the beginning of each season.

 

[QBhoy]

It’s not overpropped for sure. The rpm limiter is 4950 rpm on that engine of yours. Max rpm rating is 4800. You are hitting that. So if anything it’s underpropped

 

[achris]

It’s not overpropped for sure. The rpm limiter is 4950 rpm on that engine of yours. Max rpm rating is 4800. You are hitting that. So if anything it’s underpropped

I certainly wouldn't say under propped, I'd say 'nicely propped'.

Chris.......