Muff-Flushing Bravo 3 Stern Drives with Front Gearcase Intake

[RittSea]

Quick question about muff-flushing Bravo 3 stern drives. My Bravo 3 drives have an intake at the front of the gear case as well as the sides. When I put the muffs on the sides, the water pours out of the front gear case and doesn't make it through the rest of the engine. The Mercruiser videos simply say to "plug it up" before starting the motors, but doesn't offer any suggestions on how. So is there an easy way to do so? Is there a kit? Has anyone come across this? If so what do you use to plug this intake port? Rubber plug? Wooden dowel? What works best? Thanks!

 

[Ididntdoit]

install an eddie marine flush kit and do it the right way

 

[89P270]

Hey, Ididntdoit, Assuming you have one installed, can you send a pic. Looks like they are in bilge and basically install inline before the Bravo pickup pump?

 

[Ididntdoit]

no pics - installed one on the 250AJ i sold last year - i removed the quick disconnect fittings from the existing hose and replaced it with the eddie fitting - then i ran the flush hose up to the anchor locker where i installed the fitting......on my 300 da, i had seacocks and strainers - so i would just close the seacock, remove the cover, and run the hose right in the strainer

 

[RittSea]

install an eddie marine flush kit and do it the right way

Do you know if the Eddie Marine Flush kits are compatible with Bravo 3 drives? Their site says "NOTE: This kit CANNOT be used on engines that utilize a water pump that is internally mounted in the sterndrive" Not sure if Bravo 3 drives have internal water pumps. I don't think so, but I wanted to verify first. BTW, I reached out to Eddie Marine to ask them and have not yet heard back.

 

[techmitch]

Do you know if the Eddie Marine Flush kits are compatible with Bravo 3 drives? Their site says "NOTE: This kit CANNOT be used on engines that utilize a water pump that is internally mounted in the sterndrive" Not sure if Bravo 3 drives have internal water pumps. I don't think so, but I wanted to verify first. BTW, I reached out to Eddie Marine to ask them and have not yet heard back.

No pump in a BIII drive.

 

[89P270]

Rittsea, what he means is yes, the Eddie marine kit is compatible with your Bravo III. The Alpha outdrives have the pickup impeller in the outdrive unit itself. The Bravo's use an impeller mounted at the serpentine system on the engine. This creates a suction pulling water up through the outdrive to the pump and then through the motor and exhausts. Installing the referenced Eddie marine kit on an Alpha drive would not work and burn up the motor for lack of water as that Y fitting in the Eddie Kit has a check valve in it from what I understand. Also, to be clear "Bravo III" designation really has nothing to do with the engine other than the pickup impeller being mounted/driven by the surpentine system on the motor itself. the designation is associated with the sterndrive unit (ie Mercrusier Alpha Gen I or II, Bravo I, II, III, Volvo XDP, SP, etc) . The motor designations are thnings like 7.4L Mercruiser, 6.2L MX, 357 4V Alpha, 383 scorpion, etc.

 

[RittSea]

Rittsea, what he means is yes, the Eddie marine kit is compatible with your Bravo III. The Alpha outdrives have the pickup impeller in the outdrive unit itself. The Bravo's use an impeller mounted at the serpentine system on the engine. This creates a suction pulling water up through the outdrive to the pump and then through the motor and exhausts. Installing the referenced Eddie marine kit on an Alpha drive would not work and burn up the motor for lack of water as that Y fitting in the Eddie Kit has a check valve in it from what I understand. Also, to be clear "Bravo III" designation really has nothing to do with the engine other than the pickup impeller being mounted/driven by the surpentine system on the motor itself. the designation is associated with the sterndrive unit (ie Mercrusier Alpha Gen I or II, Bravo I, II, III, Volvo XDP, SP, etc) . The motor designations are thnings like 7.4L Mercruiser, 6.2L MX, 357 4V Alpha, 383 scorpion, etc.

Thanks!! My engines are 5.7L Mercruisers 350 Mag with Bravo 3 sterndrives. The Eddie Marine warning note only specified water pumps mounted on the stern drives. So I assumed the engine specs didn't matter. But great to know that I can use this kit! I just wish I didn't have to open the engine compartment to flip the valve before flushing. But I guess it's the lesser of all evils.

 

[89P270]

Well, the other option noted above, which I will do is the mufflers for the outdrive itself and flush at home in the driveway. I am at a loss about the intake at the front of the gear case. No one offered a description of that. Alpha drives which I am most familiar with dont have a second "intake on the front of the gear case". I watched the Mercruiser video on flushing as well and they used the mufflers along with that rod through the typical inlet to the Bravo III just like you would the Alpha. But they also referenced that potential "additional intake at the front of the gearcase". Irritates me Mercruiser referenced it but didnt provide information or photo of it to run it down. I used the mufflers for more than a decade on my twin Pachanga 350s and they were fine. Used for winterization, flushing out saltwater, etc. Its my avatar photo. I even repowered and put on through-hull water cooling in addition to the alpha drive and you just had to add a Y to the garden hose and connect another "fake-a-lake" flush cover over the through hull fitting. The Pachanga was on a trailer so I didnt need anything like the eddie Marine kit. You dont really need for the bravo either if your on a trailer. Particularly if your only out for a week or less at a time. That's how I will use my '97 270DA - On a trailer, used for 2 days or less at a time, back on trailer, tow home and flush with the Muffs/rinse with salt away - Your good til next use. I am still trying to run down the location/configuration you mentioned above AND the reference in the mercruiser bravo flush video. If you have a photo of this post it. I would be curious.

Edit: BTW its even less of a concern if you have fresh water cooling. I had on the pachanga and I have on the 270DA. So, although water flow is a bit more complicated depending on whether a 1/2 or full cooling system, its even less of a concern to flush. I remember discussing w/ the mechanic who did the install for me the stock water flow from the alpha through to the engine and mufflers when I repowered and he mentioned possibly flanging off the outdrive flow in leu of the thru-hull fittings but I think there was an issue with that idea and we wanted max cooling so we kept both flow paths. I did ruin a set of impellars after the work was done during the first spring run up on the trailer as I forgot we did the thru hull and I hadnt added the fake-a-lake to cover the through hull at the time. Ugghh

 

[paulswagelock]

Keep it simple. If flushing on land, while dry, just cover it with duct tape. Works perfect, done it dozens of times.

 

[89P270]

I think I finally found a photo. Is it the holes at the front here?? If so must be a new feature as mine doesnt have those. Huh, this must be one of the ways Mercruiser accommodated a manufacturer fix to the Bravo III continuously running hot. I added Drive showers to my last boat to accommodate hot running Bravo IIIs. The term they use is "dual water pickup". Now I see why.

 

[RittSea]

I think I finally found a photo. Is it the holes at the front here?? If so must be a new feature as mine doesnt have those. Huh, this must be one of the ways Mercruiser accommodated a manufacturer fix to the Bravo III continuously running hot. I added Drive showers to my last boat to accommodate hot running Bravo IIIs. The term they use is "dual water pickup". Now I see why.

Yes, this is similar to mine. Although mine only has one single intake port in the front. Not multiple like this one. I’ve never seen another like mine.

 

[RittSea]

Keep it simple. If flushing on land, while dry, just cover it with duct tape. Works perfect, done it dozens of times.

Thanks. I’ll try duct tape idea until I can install the Eddie Marine kits. Funny, I never even considered duct tape. Lol.

 

[RittSea]

Well, the other option noted above, which I will do is the mufflers for the outdrive itself and flush at home in the driveway. I am at a loss about the intake at the front of the gear case. No one offered a description of that. Alpha drives which I am most familiar with dont have a second "intake on the front of the gear case". I watched the Mercruiser video on flushing as well and they used the mufflers along with that rod through the typical inlet to the Bravo III just like you would the Alpha. But they also referenced that potential "additional intake at the front of the gearcase". Irritates me Mercruiser referenced it but didnt provide information or photo of it to run it down. I used the mufflers for more than a decade on my twin Pachanga 350s and they were fine. Used for winterization, flushing out saltwater, etc. Its my avatar photo. I even repowered and put on through-hull water cooling in addition to the alpha drive and you just had to add a Y to the garden hose and connect another "fake-a-lake" flush cover over the through hull fitting. The Pachanga was on a trailer so I didnt need anything like the eddie Marine kit. You dont really need for the bravo either if your on a trailer. Particularly if your only out for a week or less at a time. That's how I will use my '97 270DA - On a trailer, used for 2 days or less at a time, back on trailer, tow home and flush with the Muffs/rinse with salt away - Your good til next use. I am still trying to run down the location/configuration you mentioned above AND the reference in the mercruiser bravo flush video. If you have a photo of this post it. I would be curious.

Edit: BTW its even less of a concern if you have fresh water cooling. I had on the pachanga and I have on the 270DA. So, although water flow is a bit more complicated depending on whether a 1/2 or full cooling system, its even less of a concern to flush. I remember discussing w/ the mechanic who did the install for me the stock water flow from the alpha through to the engine and mufflers when I repowered and he mentioned possibly flanging off the outdrive flow in leu of the thru-hull fittings but I think there was an issue with that idea and we wanted max cooling so we kept both flow paths. I did ruin a set of impellars after the work was done during the first spring run up on the trailer as I forgot we did the thru hull and I hadnt added the fake-a-lake to cover the through hull at the time. Ugghh

My 330DA is high & dry stored. My Marina flushes my motors as a standard service. But I seriously doubt they do a really good job. Especially if they move a few dozen or so boats a day. In addition I suspect they don’t properly plug the front of the gearbox when they do flush. I suspect my boat is the only one with this extra gearbox intake. I’ll ask them to let me know what they actually do. But I’m afraid of what I’ll hear. When I have the time, I actually prefer to flush it myself. It’s a peace of mind thing.

 

[Lazy Daze]

Yup - duct tape as mentioned. That's all you need. But if you want to get fancy, you can get a B3 nose cone flush kit.

 

[89P270]

And I bet the marina doesnt use salt away either- Here's a look at the nose cone flush kit. I learn something all the time on this forum! thanks Lazy Daze. Still irritates me that Mercruiser didnt include this in their training video. I suppose this kind of knowledge they think you just read minds through the web to gather up. Maybe its in the newer Bravo 3 service manuals but I doubt it.

Quicksilver part 881150Q1 $39. Go figure, they have them at Walmart......

 

[RittSea]

Yes, this is similar to mine. Although mine only has one single intake port in the front. Not multiple like this one. I’ve never seen another like mine.

Correction. I took a photo and discovered that the front intake is indeed like the one 4-holed picture you posted. However, also I learned that muffs offer zero help for flushing the engine itself. Even if I duct tape these front intake holes. Water just never makes it into the engine. So I’m essentially just flushing the stern drive. So I just purchased the Eddie Marine Flush kit as recommended above. Fingers crossed, I’ll post pictures if I’m successful.

 

[RittSea]

no pics - installed one on the 250AJ i sold last year - i removed the quick disconnect fittings from the existing hose and replaced it with the eddie fitting - then i ran the flush hose up to the anchor locker where i installed the fitting......on my 300 da, i had seacocks and strainers - so i would just close the seacock, remove the cover, and run the hose right in the strainer

Quick question, I’m curious to know how the engine’s water pump doesn’t cause a back-flow situation to the T-fitting hose line during normal boating operations. I understand that closing the ball valve shuts off flow from the strainer when flushing. But when running the boat with the ball valve open should cause water pressure to both the engine as well as the hose line.

https://www.eddiemarine.com/image/data/295-50-51-53%20flush%20kit%20instructions%202.0.pdf

 

[scoflaw]

Flush muffs don't work if you also have a thru hull pickup Teed in. In that situation you need to use the toilet plunger flusher on the thru hull

 

[Lazy Daze]

It sounds like you're saying that you have a thru-hull intake in the bottom of the boat, as well as the drive? That would have been a good piece of info to add in the beginning! YES, you must close the seacock in order to flush properly otherwise you just end up sucking air and possibly even damaging the impeller.

During normal operation, both the thru hull and the the drive are under water so all is good.