Identifiy Bravo drive and lower unit
 

What ive been told is that I have a Bravo One X drive with speedmaster lower unit. I cant find any identification numbers ore any other digits on the drive to clearify this, just the IMCO and Mercruiser logos.
There is IMCO hydraulic steering with extentionbox on my boat. Drive shower and Bravo 1 26” propeller.

Is there anyone that can look at the pictures and tell me what drive and lower unit it is?


https://cimg6.ibsrv.net/gimg/www.off...cd5be6993.jpeg
https://cimg0.ibsrv.net/gimg/www.off...681fa4516.jpeg
https://cimg3.ibsrv.net/gimg/www.off...e2976fe7b.jpeg
https://cimg5.ibsrv.net/gimg/www.off...7b2530dd1.jpeg

It looks more like a sport master lower , speed master are #3,4,5 drives............the sport master skeg is longer than the IMCO sc

Here is a better picture of the drive and lower unit. Thanks!

https://cimg2.ibsrv.net/gimg/www.off...024e3e592.jpeg

thats a sport master lower and a IMCO back cap for the steering

Thanks for the help!
Do you know how much oil the bravo one X and sport master holds together?
I am considering buying the Mercruiser race gear lube 85w90. Any thoughts?

The upper could be an X or XR from what I've seen, they use the same retaining nut.

Im guessing 2.5 - 3 quarts depending on the size of the reservoir bottle, could be a little more

Looks like the bigger xr style u joints in that first pic

What u joints do you mean?

Hard to see the difference between the X and XR

Thank you!

If the top cap is removed U can tell by what kind of gears found

All Merc Bravo style drives take about 3 quarts of gear lube.
Its a swept back upper with Imco steering back cap and it also has the finned top cap that XR's have.
Most likely an XR upper, but you would need to pull the top cap or back cap to verify what gears it has.

Thanks. I will see if i take of the top cap. But it is more like a XR then X. If I look at a old picture of the Bravo drive, I think I can see a XR decal at the back cap, but im not sure.

Thank you!
Yes it is more like a XR upper with the finned top cap.

If I pull the top cap or back cap, do I need to replace any o-rings or sealant if I want to check the gears?

And my second question. I have drained the gear oil and about to order new oil.
Wich gear oil should I use and how do I identify wich gear oil it was in the drive?
The gear oil in the drive and gear oil in the reservoir is blue/green color.

Should I use the same oil that was in the drive, or can I order the Mercury Racing gear oil SAE 85W-90?

When I search for the SAE 85W-90 oil, it looks like the color is the same as the oil in my drive. Blue/green color.

Many use different lubes but suggest just using Merc 85w-90 Green stuff

Removing the rear cap will not normally need a new o-ring, but if tis damaged then it will need it. The upper cap shows signs of pitting. My thought about the rear cap was because the top showed pitting, so concern if rear also has same. Can also see if there has been lube leaking into shift area. If it was then would also see lube on shift fork

Do you want to send me a link to the specific gear lube you mean? When I mentioned the 85w-90 I meant this one. It says dont mix with other brands/gear oils.. But I cant tell wich one I have today :faint2:

https://cimg2.ibsrv.net/gimg/www.off...2bae3a9c3.jpeg

Okey, so you mean its better to remove the rear cap to identify two ”problem areas” at the same time?

The bluish green gear lube is Merc(Quicksilver) High Performance Gear lube.

The pic you posted is the new Merc Racing Gear Oil which is supposed to be even better than the Merc (Quicksilver) High Performance.

The top cap and back cap O ring seals will most likely be fine to reuse. I would just pull the back cap.

Thank you Griff! I just pull the back cap then.

Is it OK to mix the Merc Racing gear oil with the Quicksilver oil?
Or should I drain all the oil before I buy and fill it with the Merc Racing oil?

I think like this, as long as the both oil is syntetich, the Merc quicksilver is 75w-90 and the Merc Racing is 85w-90, it is good to go?:drink:

Mixing is for the most part is in regard to having one kind of lube in and adding another to fill. Your drained, so use only one kind

X and XR both have a finned top cap. Take extra care if you pull the rear cap to locate the shift arm and o-ring properly,both are slippery little suckers.

The Merc/QS Hi Perf is 90wt https://www.walmart.com/ip/Mercury-9...hoCKhAQAvD_BwE

If you swap to the Merc Racing, then drain the drive completely and have some extra on hand since it is not as readily available if you need to add some.

Thanks all of you for the information!
Is it a big difference between the Merc Quicksilver and Merc Racing oil?

Wich one is best for my setup?
Both is available to buy here in Sweden.
The Bravo One XR drive is specified in the Merc Racing oil.

My opinion
QS is a mix of dino and synthetic lube, racing is 100% synthetic
Most like synthetic
Many of the high HP guys use AMSOIL extreme lube
Depends on your app, if your puhsing a lot of HP suggest Syn otherwise either will work
I use both, runabout QS and Cruiser Racing

I have the Merc 496 HO, so it is not that much horsepower. But it sounds like the Merc Racing is better so I think I go with that.

Completely drain all the oil out from the reservoir tank system in the engine compartment too and fill it upp with new fresh oil in the reservoir and the drive.

Identify gear ratio
 

I found a serial number right beside the engine serial number.

https://cimg3.ibsrv.net/gimg/www.off...b1c5ff48f.jpeg


Its hard to see what number it is, but I think it is 0W293253. When I search after this number it tells me the drive is a Bravo 3 gear ratio 2:1.

Ive been told my drive is a Bravo 1 X/or XR.
With a sportmaster lower.

https://cimg8.ibsrv.net/gimg/www.off...7f4245204.jpeg


How do I calculate the gear ratio without removing the top cap and count the gears?

Is it possible to rotate the engine clockwise with forward gear and look how the prop moves, and then calculate the gear ratio?

Very thankfull for answers!

https://cimg0.ibsrv.net/gimg/www.off...d9fe09dea.jpeg
Looks like the serial number right here, circled.

Yes, Mark the crank pulley and prop.
Locate the slave relay and remove the plastic cover from the top terminals
Place in gear, and jump across the top terminals this will engage starter.
Let motor rotate 10 times to get a better count

Theres no serial number there. Its new decals only where you can write the serial number.

Thank you, will test this and se if I do it right.

I must know the gear ratio to be able to choose the right prop when testing.
I have calculated the prop slip with the data I collected from the last run:

~ 50 mph
~ 4800-5000 rpm (Merc 496 Mag Ho)
Boat weight ~5500 lbs
Bravo 26p prop

With 1,50:1 in ratio I get ~35% prop slip, which is very much.
If I count with Bravo 3 ratio 2:1, I get ~13% prop slip..

I dont think your 4th octet is a 9..........might be 203253 ?

Note: The drive will probably go into gear easy enough, but it may not want to come back out without the drive rotating. If it takes to much of a pull, jump the solenoid again while pulling to neutral

If I search with 203253 I dont get any results, only when I put a 9 instead of 0.. :(

Im not that good at English, but I will try to understand what you mean :D