Lost my lower unit last week, I didn't hit anything she just blew, like my loving wife when I told her how much it would be to get back on the water, anyway that's another story. Question what is or or what have you guys found required or needed to properly break in a new lower unit. I was going with a re-manufactured from Crowley marine but there out of stock for at least a month but can get me a new one from Yamaha at a discounted price. Thanks for your input.

What Motor do you have. I may can get you one quicker.
Note: Gearcase assemblies are shipped without oil.
1.Fill unit with manufacturer's required gear oil to recommended level.
2.Adjust RPM at idle to manufacturer's specifications.
3.Proper shift adjustment is essential.
4.Jumping out of gear: If the unit will not stay in gear, the clutch dog has probably been rounded off. Rounded clutch dogs are caused by, but not limited to, improper shift cable adjustment, inadequate shift travel, idle RPM too high, and/or shifting too slow. Rounded clutch dogs are not covered by warranty.
5.Avoid full throttle starts.
6.Do not operate at constant speed for extended periods.
7.Shift into forward gear a minimum of 10 times during break-in, with moderate engine speed after each shift.
8.Do not exceed 75% of full throttle during the first 5 hours of operation.
9.During the next 5 hours, full throttle should not be maintained for long periods.

http://texasoutboards.com
I bought one from these guys took less than a week Goodluck and break it in right

Thanks, that lower unit is produced by SEi, they don't have one for a 2008, 250 HPDI but thanks for trying to help.

Only a few reman. or over seas companies require break-in on lower unit assemblies.

Just had mine replaced with a new factory one, and nobody mentioned anything about a break in period.

Thanks guys, I had a boat manchenic tell me drive it like you stole it, Yamaha will send you a new one if it breaks in less than a year, so break if fast if your going too. With tournament season here I don't have time to be putting around.

If I followed this mine would break in 13 months! Honestly I've never heard of a break-in period. Possibly because the break-in period/procedure for new motors is adequate break-in for the lower unit also. Sounds like some good knowledgable info in some of the other posts above. Would a simple call to the shop answer your question for sure?

I would't go with an SEI. I'm in the process of replacing mine with a TM case (Merc). After I fried my factory one in late August, my SEI is coming apart already. Just my 2 cents though.

just drive it.

I've got an extra HPDI lower unit if you want to buy it.

Never heard of break in but was told on mine a few years ago to run it for 4-5 hours and change the oil in it.

Wow thanks, just paid for a new one, pm me I might want a replacement spare!

Can't get an SEI for HPDI 250 3.3 I tried.

Your pm box is full