30ctsutphen

I know theres all of about 4 of us running OBs here on OSO but I figured a discussion on lower unit upgrades might be good.

I have 3.0 300X with sportmasters and I was looking into up grades, This year I plan to re seal, re bearing, spray weld the shafts for corsion resistence, and add lakeland marine vent kits.

I know there are some stronger seals available but to me holding the pressure in doesnt seem to make sense.

Anyone have any other upgrades or info?

HIGH LIFE

Lakeland vent kits worked for me. Do you have hardened steel drive & prop shafts or SS ? Do you have 2 piece drine shafts ? Size of mids, 20" or 25" ? By the way like your PORTA LIFT !!! "HIGH LIFE"

chardt

I blew 3 lowers in the first 20 hours on my 32 skater so I installed the Lakeland vent kits and the 4 seal billet aluminum seal carrier from Taylor marine. Since I did this I have 200 hours on my drives. I did break one prop shaft this summer, but that was because my prop shaft bearings had 15 thousands play. The four seal carrier from Taylor marine goes between the water pump and the gear case. The four seals provide extra protection from water coming through the drive shaft. When the gearcase gets hot the seals vent the pressure then when your gearcase cools your gearcase is under a vacuum and ingests water. I did both modifications and am very happy I did.

Carl

X-Rated30

What year are y'alls engines? I just went to 250 XS Sports in mid July. On the last run of the year, I hit the hour meters and had 54 hours on each motor without a hickup. I am running 3 blade 15x32 props and if I am moving, chances are I am wfo.

Maritime_Eng

What true speed are you running with your setup? What RPM?

Maritime_Eng

I have 116 hours on my 250xs's and I had one lower break a vertical shaft right at the upper bearing in the case. Other than that they have been running well.

chardt

I am running three 2001 Mercury 300x spinning 14.5x35 3 blade cleavers (speed props)or 14.5x35 4 blade et's; the 4 blades are less wear and tear on the lowers.

Carl

30ctsutphen

High life
I have no idea whats inside these. The boat was Bob Mc coys and worked on at double R perf. I probably should call them for info. I know it blew up a lower and had a new lower installed 2 years ago. the other as far as I know is the factory 2005 unit from when the engines were bought. They only have 70 hrs on them so far.

Its a 20 inch mid set up. I had 25 inch CLE's on my 26ft rum runner so I know all to well how finicky these things can be. I should have put the lakeland marine vent kits on day 1 but I wanted to use the boat and figured if I was diligent with oil changes I could get through the first season.

I didnt think the billet seal kit was needed if you added the vent kit but its cheap insurance I guess. Its annoying to me that they can't make a better F ing lower unit than they do. How many years have we been dealing with this merc lower issue?

My 200;s were 1993's and were still seeing the same problems.

30ctsutphen

The porta bracket is great too. Its kind of a PITA because it doesnt have a height gauge so you need to either go by feel or look back at it.

Other than that It works really well and sure is nice when you pull in areas were the water is low and unknown too.

X-Rated30

I am on the rev limiters and have only seen 90. I need another set of props, but after dumping $40k into the swap, I figured 90 was fast enough til this year.

I think these props have been trimmed down til there isn't enough meat left to push enough water. Gonna have a prop guy check them for true pitch, etc before I order the new set from BBlades, so I will have a point of reference.