Installation of Lower Unit?

[77SceptreOB]

How difficult / complex is it to install a new lower unit on a Yamaha 225 (V-6 Excel)??

My current LU is shot and need a new one. I can buy a new one for appox $800 that has a 3 year warranty.

Is this install a DIY job or one for the dealer/marina/shop??

[wtenglish]

I haven't personally installed a lower unit but I watched the mechanics replace one on a Yamaha 250 Saltwater Series after it crapped out on the way to the Bahamas two summers ago. To the best of my knowledge it only involved removing about 4 bolts and sliding it off. After that experience I wouldn't have any reservations about trying it myself if I was in your position. One thing I would need information on would be the proper lubrication level in the unit itself.

[Bigshrimpin]

It's an easy job with 2 people and not too bad solo (if you use a ratcheting tie down strap).

[Greno]

just remember to have the shifter in the same gear as the lower unit. I have done one yamaha and my mechanic said to make sure it was either fully in forward or reverse while installing, making sure the shifter was the same. its not hard, just 4-6 bolts and the cooling hose. Don't forget to change the impellor while it is apart.

Eric

[77SceptreOB]

Don't forget to change the impellor while it is apart.

If I get a new lower unit, doesn't it include a "new" water pump/impeller??? I thought it would be part of the assembly.

[Greno]

Depends. The guys I know that rebuild them do not put a water pump on if you bring it to them. It is just a few bolts and few dollars. May want to ask when you buy it.

[Old'sCool]

You drop/install a lower unit every time you change water pumps. I do my Yam 250 alone and the shifter splined shaft, pitot tube, and drive shaft must be aligned. It literally falls into place when correct. Run it on the hose and shift from f-n-r to be sure. It's definately not something a shop has to do. I use anti seize on bolt threads, rubber boot, and split line at assembly. Make sure it's full of gear oil...

[red20]

I've done it many times over the years solo. Little tip, remove the prop if it is stainless - that'll knock a few pounds off of the lower unit and makes it a bit easier to handle. It is also a good time to inspect the seals (not in your case since you are putting on a new one).

[Caymanboy]

I wouldn't use anti sieze, that contains copper, which along with the aluminum and stainless steel, makes a nice battery, use Yamaha or Triple guard grease, two people is easier, test the shift before all the nuts are on and tight, just in case it didn;t get lined up. Good luck.

[Fr. Frank]

Don't use Anti-seize in saltwater. Not only does it accelerate electrolysis, it also turns from an anti-seizing compound to a permanent epoxy over time and with the application of electricity. Working in marinas we saw it repeatedly with people who used it on propeller shafts, and then didn't remove and lube the hub for a couple of years. We would have to burn the rubber hub with a torch to get the prop off the hub, and then sometimes even have to split the brass hub with a die-grinder to get it off.

Lube the bolts (and the propeller shaft) with a marine-grade grease, preferably lithium grease or molybdenum-sulfide grease. Lithium based grease is usually white or light yellow in color. Molybdenum-sulfide is usually bright red or bright blue. Don't use any grease with graphite. In saltwater, graphite grease clumps and hardens.

I use CRC or Pennzoil brand lithium marine grease for bolts, props, and axle bearings. I also spray my whole powerhead and tiller arm with Fluid Film after rinsing the motor post usage.