Help brainstorm low water flow overheating
#11
Platinum Member
Platinum Member
As stated before, it sounds like Bravoitis to me.
#12
So now I have more perplexing information. After messing around with the pump hoses and pulling the feed line off to see how well the raw water pump was pumping, I put it back together. Then we went out last night for around 2 hours, mostly low wake cruising but on plane a couple times…
She never went above 140* for 2 hours, oil pressure stayed identical to the starboard motor and was actually running around 20-30* cooler than starboard the whole night.
So now I’m thinking/hoping that maybe there was an air bubble or a kink in one of the hoses or something as it appears the issue is completely solved. Not ready to celebrate yet though so I’ll probably take her out again later today for a while to confirm
She never went above 140* for 2 hours, oil pressure stayed identical to the starboard motor and was actually running around 20-30* cooler than starboard the whole night.
So now I’m thinking/hoping that maybe there was an air bubble or a kink in one of the hoses or something as it appears the issue is completely solved. Not ready to celebrate yet though so I’ll probably take her out again later today for a while to confirm
#13
Registered
I'd check for "bravoitis" on the inside of the boat where the water neck comes off the transom. If that is the problem, the new Mercury hose kits have an improved design that is less prone to having this issue in the future.
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Romeomikehotel (09-19-2024)
#14
So another update:
Ran it for about two hours today at low wake and she stayed very cool, then at then end I got her on plane for about 5 minutes and by the end she was starting to heat up again. As soon as I came oof plane the temps dropped back down to 120* but clearly something is still not right.
More research to do.
Ran it for about two hours today at low wake and she stayed very cool, then at then end I got her on plane for about 5 minutes and by the end she was starting to heat up again. As soon as I came oof plane the temps dropped back down to 120* but clearly something is still not right.
More research to do.
#15
Registered
Ditto on checking Bravoitis. Be aware if you have a Y pipe or anything in the way installation of the new main water inlet hose is going to be damn near impossible with engine in place. Different waterpickup sounds like a new can of worms. Look at the install instruction for the main water inlet hose thru the transom and see if you can access the hard suction line fitting where it passes thru the transom.
#16
Registered
Doesn't the Bravo 1 drive benefit from water flow cooling?
#17
BEACH PARTY
Platinum Member
Bravoitis.
I have dealt with this on a couple of boats - my old 242 LS and my Cigarette Bullet (when my buddy owned it). One the Bullet we added thru-transom pickups to solve the problem - fortunately the transom was solid so no surprises. The Formula... not so much. The Silent Thunder platform caused leaks and turned the transom into confetti.
The bellhousing needs to come off and you need install a new hose and plastic fitting. The really good way to fix is with a repair kit that has a stainless fitting that feeds into the hole from the engine side. Not the easiest of jobs to do - replace the driveshaft, shift bellows, and the gimbal bearing while you're in there. If you go the route of adding a transom pickup, you'll need to figure out how to add ball valves and sea strainers - hopefully no issues with the transom.
Side note... get rid of the Silent Thunder for sure - that thing is a transom killer.
I have dealt with this on a couple of boats - my old 242 LS and my Cigarette Bullet (when my buddy owned it). One the Bullet we added thru-transom pickups to solve the problem - fortunately the transom was solid so no surprises. The Formula... not so much. The Silent Thunder platform caused leaks and turned the transom into confetti.
The bellhousing needs to come off and you need install a new hose and plastic fitting. The really good way to fix is with a repair kit that has a stainless fitting that feeds into the hole from the engine side. Not the easiest of jobs to do - replace the driveshaft, shift bellows, and the gimbal bearing while you're in there. If you go the route of adding a transom pickup, you'll need to figure out how to add ball valves and sea strainers - hopefully no issues with the transom.
Side note... get rid of the Silent Thunder for sure - that thing is a transom killer.
#18
Registered
Google this-
bravo 1 waer cooling thru drive
There are several threads on drive cooling thru the drive via water pickups. I have a dump valve that is spraying a solid stream at speed thru a 3/4 hose at top cap. Reading some of the threads on the cooling I am thinking of finding a way to get that stream directed more towards the side of the upper. Perhaps something on the top cap to just catch the water and direct or let it flow down the sides.
Something like this cap-
https://www.ebay.com/itm/28221628448...waAnweEALw_wcB
So if you go with thru hull pickups for cooling water you will need to provide additional cooling or a way to allow water to flow thu the drive. Seems the simplest solution would be to just repair the Bravoitis. O would suspect using pickups could introduce water pressure problems at speed.
bravo 1 waer cooling thru drive
There are several threads on drive cooling thru the drive via water pickups. I have a dump valve that is spraying a solid stream at speed thru a 3/4 hose at top cap. Reading some of the threads on the cooling I am thinking of finding a way to get that stream directed more towards the side of the upper. Perhaps something on the top cap to just catch the water and direct or let it flow down the sides.
Something like this cap-
https://www.ebay.com/itm/28221628448...waAnweEALw_wcB
So if you go with thru hull pickups for cooling water you will need to provide additional cooling or a way to allow water to flow thu the drive. Seems the simplest solution would be to just repair the Bravoitis. O would suspect using pickups could introduce water pressure problems at speed.
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TomZ (09-21-2024)
#19
Gold Member
Gold Member
From the pictures you posted in the other thread and the fact you’re keeping it in the water I would almost guarantee, as others have mentioned, that your hose in you transom assembly is corroded, the plastic insert fitting has possibly collapsed and you likely also have growth in the drive.
pull drives, yank motors and install new transom assemblies is the proper way to fix it. I only say replace TA’s because I’m sure the bellows are at end of useful life, gimbal bearings are worn, swivel seals are gone, etc, and as someone who has made the mistake of rebuilding TA’s before it’s not cost/time smart.
pull drives, yank motors and install new transom assemblies is the proper way to fix it. I only say replace TA’s because I’m sure the bellows are at end of useful life, gimbal bearings are worn, swivel seals are gone, etc, and as someone who has made the mistake of rebuilding TA’s before it’s not cost/time smart.
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TomZ (09-21-2024)