Yamaha 2001 OX66 Lower Unit Replacement Sterndrive Engineering

[eejorgensen]

My lower unit had water in the oil. The dealer says there is so much corrosion that they can't replace the seals without breaking the bearing. Since the unit is 20 years old and has always run in saltwater, I believe him. He quoted me a new lower unit for from Yamaha for $2800.00 plus installation.

I was looking online and found new units from Sterndrive Engineering for $895.00 with a full three year warranty. I know that this is coming from China or Taiwan. I did several online searches and for the most part people were happy, but there are always a few horror stories. Most people said there was no issues with the warranty returns. Yea I know you get what you pay for.

Has anyone else used this product and what was your experience ?

Thanks,
Eric
2001 2100DV

 

[warthog5]

Dumping more money in old technology is not something I'd do.

 

[PKS1801]

Not everyone can afford to buy a new motor, every time their old one breaks.
Eric, I am pulling for you, because I have a 2000 OX66. That said, it is a 20 year old motor. Is a used Yamaha out drive something you would consider? If so, I would be looking at dealers whose clientele is primarily lake boaters, on large inland lakes, for a replacement.

 

[Brent]

Where do you boat , how far from shore and are you keeping the boat?

 

[Brent]

M2cw I didn’t buy a SEI LU but bought a refurbished one from Marine Rebuilds by Tampa. Full inspection and all Yamaha parts.

 

[John_Madison CT]

Check Facebook marketplace. You can often find a OEM Yamaha lower unit for the Ox66 around $500-$700. FWIW, the Ox66 is a great motor and spending even $1000 to keep her going is well worth it.

 

[eejorgensen]

Thank you for all the feedback. I do all my fishing out of Ocean City, MD. All the trips are to the local wrecks which are within 20 miles. If I breakdown off shore these is always BoatUS towing. That's why i carry the unlimited package. I think that motor is the best Yamaha ever made. It's 20 years old and I still have full compression in all the cylinders. I have always used ethanol free fuel along with Ring Free. No gas station.

After watching a number of You Tube video's on how to replace the seals, I am going to give it a try. I think the dealer (Who I have used for 30 years and I really respect) just didn't want to put the time into fixing the problem. They were afraid of breaking the upper bearing which can be replaced. The amount of time that they would need to put into the job didn't make sense. I have always turned by own wrenches and have the tools to fix the issue. If I screw it all up, then i will buy a new lower unit.

If the motor ever dies, I plan on putting on remanufactured head. I have seen prices in the $3500-$4000 range. I just can't justify the cost of a new motor on a 20 year old boat. My 2100 is in perfect condition, and when I showed Linwood Parker a picture of my boat last year at the Balt. boat show, he was amazed at how good it looked. He even brought over all the sales guys from Tri-State to show them how good a 20 yr old boat can look if you take care of it.

I will let you know how I make out in the next month with the rebuild.
Thanks,
Eric

 

[Gsully23]

Thank you for all the feedback. I do all my fishing out of Ocean City, MD. All the trips are to the local wrecks which are within 20 miles. If I breakdown off shore these is always BoatUS towing. That's why i carry the unlimited package. I think that motor is the best Yamaha ever made. It's 20 years old and I still have full compression in all the cylinders. I have always used ethanol free fuel along with Ring Free. No gas station.

After watching a number of You Tube video's on how to replace the seals, I am going to give it a try. I think the dealer (Who I have used for 30 years and I really respect) just didn't want to put the time into fixing the problem. They were afraid of breaking the upper bearing which can be replaced. The amount of time that they would need to put into the job didn't make sense. I have always turned by own wrenches and have the tools to fix the issue. If I screw it all up, then i will buy a new lower unit.

If the motor ever dies, I plan on putting on remanufactured head. I have seen prices in the $3500-$4000 range. I just can't justify the cost of a new motor on a 20 year old boat. My 2100 is in perfect condition, and when I showed Linwood Parker a picture of my boat last year at the Balt. boat show, he was amazed at how good it looked. He even brought over all the sales guys from Tri-State to show them how good a 20 yr old boat can look if you take care of it.

I will let you know how I make out in the next month with the rebuild.
Thanks,
Eric
View attachment 27583

I'm a yamaha tech and work at a dealership. My lower gave out soon after I bought the boat (trade in earlier last year). I priced out rebuilding with oem parts at my cost (dealer cost) but 2 gears cost more than the whole SEI. Plus, the sei came with a new water pump, but I swapped it for oem anyways. I put over 160 hours on it and over 1000 miles since July and am more than happy. Being a tech I was worried, but I figured the cost with the warranty vs yamahas which only comes with a 1 year warranty.....I didn't have much to lose. Maybe I was one of the lucky ones.

 

[GotChrist?]

There is an SEI LU on my 96 225. The motor was originally from a set of twins and had backward rotation so the previous owner installed a new LU from SEI to make it normal rotation since it's a single engine set up. I've had it going on 3 years. He ran it for 1-2 years, maybe more (I forget how long he owned the boat).

 

[eejorgensen]

I was able to replace the oil seals in my lower unit. The upper seal is harder because you need to remove the seal housing. There are a lot of videos on you tube using pullers and screw drives (bad idea). I made a simple jig to pull the housing. I removed the seals around the prop shaft using drywall screws (hack). I didn't use a drill, I screwed the screws into the oil seals with a screw driver and closed end wrench so I didn't score the shaft. My lower carrier bearing housing is starting too corrode a little, but that didn't affect the seals. The dealer didn't want to pull the housing because they were afraid of breaking it. The dealer will only service per the manual and I am sure the drywall screw hack isn't part of the manual. I used a 1 1/4 inch socket to put press the seals in the upper housing and a piece of 1 1/4 inch sch 40 pvc to put in the lower seals.

This job isn't that hard and if you can replace a water pump and get the woodruff key out you will be fine. You need to be careful when removing the seals not to scratch any surfaces.

Here is a link to the video I made.

I saved buying a $1200.00 replacement lower unit.

 

[pelagic2530]

EXCELLENT video. This is the type of information that makes this site so valuable! Very well done, great research and fantastic work.

I agree that the older Yamaha 2-strokes are great engines and are worth working to save. The only reason that I'm parting ways with mine is that the steering bracket assembly on both motors (1995 vintage) has corroded to the point of failure (I can bend them back and forth by hand). Replacing this part requires pretty much disassembling the entire motor, and the cost/time associated with doing so on two motors is just not worth it. But I can say that there's not a lot of 25+ year old outboards that you see running around out there, and that alone is a testament to the engineering of these old dinosaurs! I'm happy to hear that you were able to keep yours chugging along.

 

[eejorgensen]

Paleagic2530 Great point about the steering bracket. I plan to do a through inspection of mine for rust and apply some fresh paint. That part looks like cast iron, but i am not sure.
EJ

 

[Antidote]

I bought one from SEI for and old Mercury Saltwater 150 2 stroke. I broke it in as described in the instructions and never had a problem. Sold the boat and engine and told the new owner and even gave him the box it came in, in case he had a problem. Of all the things he called me about, the lower wasn't one of them.

 

[Gsully23]

I just wanted to give an update to my previous post with my experience with my sei drive on my f150.

I went to take the boat off the life 3 weeks ago and noticed oil coming out of my water pickup. Ruined our Saturday but hauled it out and drained the oil. A bunch of water came out, probly 80% water to oil ratio. Called sei, sent it back in after it failed a pressure test. Sent it out and just recieved the unit back today. I diagnosed the issue before I sent it out and it wasn't bad seals, but actually a pressed on bushing on the driveshaft that the seals ride on cracked and you can't buy it, it is part of the driveshaft assembly. It was a 2 week turn around time, but on the failure analysis it doesn't show a driveshaft replacement. Have yet to pressure test it. Luckily I was able to rebuild my original lower unit within a few days so I only lost 1 weekened of boating. Overall the experience was very easy to deal with besides the $120 to ship it back. Save your box to save you a headache down the road. So I'm hoping when I open the box I see a new driveshaft. They stated they replaced bearings, seals, and impeller.

 

[Gsully23]

Also to remove that up carrier, I found my mini snapon slide hammer popped it out of my 05 with one or to strikes. And also removed 2 others this same way after without any hassle. Harbor freight sells a knockoff of my snapon one which I'm sure would work just as good. It has a small enough lip attachment to fit down the side of the carrier and a one or 2 pops on each side pulled them right out everytime.