Operating Temp Fluctuations - Page 2 - Maxum Boat Owners Club

Dustin07 · 08-10-2020, 05:11 PM

We did pretty much everything you could do. Replaced impeller, then full water pump, thermostat, bypassed heaters, back flushed, new serpentine belt, finally tore apart exhaust and flushed risers. They did have some slag build up but they were fine. nothing severe. Last solution: we did a thru-hull setup this weekend. It was a full project with all nice (expensive) bronze fittings, bronze ball valve shutoff, grocco strainer, etc. This final solution fixed it, so I am chalking this whole overheating issue up to bravoitus.

mmwjr · 08-10-2020, 05:40 PM

Did you install a block off plate at the transom for the Bravo water hose?

jparsons121 · 08-10-2020, 05:45 PM

If the thru hull intake solved it, I bet you did have the Bravo-itis that is due to the restriction of the passage coming through the transom assy. This is a choke point for all BII's as well, not just the BIII mentioned in a previous post.

Good Luck!

mmwjr · 08-10-2020, 07:43 PM

All Bravos use the same transom assembly and are all susceptible to restricted water flow.

Dustin07 · 08-18-2020, 08:20 PM

Hi Guys,
the through-hull sure seemed to fix it. It was about a 3 week + project that I started addressing early in June/July brainstorming with my local mechanic hoping to have the boat ready for a week long trip August 11th.

as I think I noted:

we did everything mentioned in this thread. back flushed, bipassed heater, flushed and checked risers, new thermostat, new serpentine belt (it was due), new impeller, new water pump. nothing worked. so we did the thru-hull (everyone spells that combo differently it seems) and we pulled a 250 mile trip over the course of a week with zero heating issues.

Now i'm dealing with a leaking drive lube monitor, but I've got another thread started on that.

All in all the boat handled well. tallest seas we saw were reported at 5ft although some of the rollers were considerably longer. in small cop of 2-3ft the boat acted like it didn't even notice. we cruised mostly at 3k to 3200 rpms and around 20 knots. however the few times I did push it up to 3600 wife complained a bit, lol

it ran great though!