New outdrive - break in on land?

[freak007]

Hello, I just finished replacing my Alpha one outdrive with a new unit from SEI. I am all ready to break it in now and had a question about break in...

Once everything was put together I fired it up and let it idle (in neutral) for 10 minutes... I then performed the following:

Idle in forward for 5 minutes
Idle in reverse for 5 minutes
1000 RPM in forward for 10 minutes
1000 RPM in reverse for 10 minutes
1500 RPM in forward for 15 minutes
1500 RPM in reverse for 15 minutes
2000 RPM in forward for 30 minutes

At that point in time "Mamma" called 'cause dinner was ready so I stopped... I noticed after the first 20 minutes in gear the idle had come up to ~750 RPM (from 500 when first installed) and after 50 minutes of being in gear the idle was up to ~1000 RPMs... I attributed this to the gears wearing in and having the correct gear ratio (some dumb-***** had installed 1.81 gears on a 120 Merc)...

Because I am in the Army (working 12 hour days 6-7 days a week), live an hour from the nearest (decent) lake... and have a wife and two kids (oldest is 3) it is nearly impossible for me to conduct a 10 hour break in on the water in the amount of time left in the season (upper Mid-west)... I do intend to take it out tomorrow and hope to get 3-4 hours in...

My question is: can I safely consider my outdrive to have ~90 minutes of run time on it, or should I perform the entire break in on the lake?

 

[Don S]

Re: New outdrive - break in on land?

With Merc drives, you put the unit on the boat. Go boating and change the gear lube at normal intervals. No break in or any other hoops to jump thru.
They are gears and bearings. Just like Volvo, OMC, and Mercruiser who have never had a breakin procedure for outdrives.

 

[freak007]

Re: New outdrive - break in on land?

Thanks Don, but are you sure that it requires no break-in? This comes directly from Mercruiser manual #6, SEI's instructions are similar:

Sterndrive Unit 10-Hour
Break-In Period (New or with
Replacement Gears)
1. Avoid full throttle starts.
2. DO NOT operate at any one constant speed for
extended periods of time.
3. DO NOT exceed 75% of full throttle during the
first 5 hours. During the next 5 hours, operate at
intermittent full throttle.
4. Drive unit should be shifted into forward gear a
minimum of 10 times during break-in, with run-in
time at moderate RPM after each shift.


My "other" hobby is drag racing... I don't do a "break in" with the exception of seaiting the rings... Simply because my philosophy is if she breaks when I hammer on it on the first pass it would have broken no matter what kind of "break in" I did... new parts don;t get stronger with time... But then I had to wonder... maybe the manufacturer knows something I don't??

 

[Don S]

Re: New outdrive - break in on land?

That is a carbon copy of the engine breakin procedure.
Worry if you want or go boating. Either will work.

 

[Bondo]

Re: New outdrive - break in on land?

Ayuh,.....

And as with Any other Break-in procedure,...
It only really Works,.. Under Load....

Just Go Boating....

 

[JustJason]

Re: New outdrive - break in on land?

ive installed a few of the sei drives and here's what I do.

First i fill it with regular gear lube, the cheap stuff
Tell the customer to go boating for 10 to 15 hours
then i cange out the gear lube with Merc high performance, the good stuff

then after that just change the gear lube once a season and keep an eye on it when possible.

thats it.

 

[freak007]

Re: New outdrive - break in on land?

Thanks guys... I just got back and had a blast... Its amazing what the correct gear ratio will do. now I need to rebuild the carb to get rid of the stumble @ 1500 rpms, then install some Smart Tabs... then I can tell for sure if I need to re-prop it...

I did several tests I got 4000 RPM @ 2100 pounds with a 15 1/4 x 21 (I was getting 3300 with the old outdrive),
4150 RPMS @ 2100 pounds with a 14 1/4 x 17
4000 RPMS @ 2100 + a tuber with the 14 1/4 x 17
4100 RPMS @ 2500 with the 14 1/4 x 17...

Normal load is 2700 or 2500 + a tuber...
both props are aluminum 3 blades, the 21 is in good shape, the 17 is fair...

 

[Bondo]

Re: New outdrive - break in on land?

I got 4000 RPM @ 2100 pounds with a 15 1/4 x 21
4150 RPMS @ 2100 pounds with a 14 1/4 x 17

Ayuh,..... 4" of Pitch,+ only 150rpms,..??..??

 

[freak007]

Re: New outdrive - break in on land?

Ayuh,..... 4" of Pitch,+ only 150rpms,..??..??

thats my thoughts as well... but the tach has been confirmed accurate... I checked it against my Snap-On timing light... The only thing I could think of is the prop damage is holding it back...

EDIT - Also I KNOW the 15 1/4 x 21 is a 15 1/4 x 21... the other one I was told was a 14 1/4 x 17...

 

[freak007]

Re: New outdrive - break in on land?

Ayuh,..... 4" of Pitch,+ only 150rpms,..??..??

I think I figured it out...

SMC 380-C = 15 1/4 x 21 with a 3* aft rake...
48-78-118-17 = 14 1/2 x 17 with a 16* rake

 

[wca_tim]

Re: New outdrive - break in on land?

on break-in with sei drives. The reason they recommend breakin is because unlike the merc drives, the gears are not laped at the factory (closes analogy to engine build / breakin would be not honing the cylinders). The gears need time to wear in a larger contact area on the faces of the teeth prior to putting heavy loading on. Why you ask? (and i did some homework when i installed my sei drive last year). Because when unlaped gears are pushed hard, the loading on the shafts and bearings isn't true and introduces errors in all of the above. The wear patterns will not be set up right from the beginning, vibration will be greater for the long run and there is a good chance that the drive will not withstand the same length of service and / or handle the same amount of power before breaking.

very different then breaking in an engine.... any kind of well built engine where all of the bearing surfaces are machined to much tighter tolerances, polished and honed...

and no I didn't folow sei's break-in procedure to the letter... I would also change the lube more than they recommend. I changed it every 5 hours or so until I quit getting metal filings out...

 

[freak007]

Re: New outdrive - break in on land?

Thanks Tim... but as the song goes "It's a little too late to do the right thing now"... I took it out today for about 3 1/2 hours... I was fairly eask on it for the first 20-30 minutes... then I ran it like "normal"... mostly cruising at 2500-3500 RPM with a many WFO blasts (some being 3-4 minutes long)... I even pulled a tube for 30 minutes or so... hopefully it'll be all right...

 

[wca_tim]

Re: New outdrive - break in on land?

I was into mine (sei lower only) all the way by 5 hours... running for 30 min plus at 90% throttle... 50+ mph behind the v-6 I had in the boat then... so far after about 70 hours total it's holding up (knock on wood). I'm a little impatient... I did change the lube before I hammered it though...