Bravo 1 to Bravo 3 Conversion

[Jesse Walter]

I have 2 Stingray boats. I recently bought a 2007 250CR with a 5.7-300hp and a Bravo 1. I also have a 2004 240CR with a 6.2-320hp and a Bravo 3.

My question would be can I simply swap these outdrives? I'd really like to have the Bravo 3 on my 2007 250CR. Its in a lot better shape than the 2004 with very low hours on the engine. 6.2 isnt in the best condition.

 

[Scott06]

I have 2 Stingray boats. I recently bought a 2007 250CR with a 5.7-300hp and a Bravo 1. I also have a 2004 240CR with a 6.2-320hp and a Bravo 3.

My question would be can I simply swap these outdrives? I'd really like to have the Bravo 3 on my 2007 250CR. Its in a lot better shape than the 2004 with very low hours on the engine. 6.2 isnt in the best condition.

yes you can but depending on the drive ratio you may need to reprop. Best bet would be to see if the 2007 was offered with a 5.7 B3 and what ratio and what props it would have come with to get a good starting point. I would suspect a smaller boat with bigger engine would have a lower (numerically) gear ratio and or more prop pitch than would work in a bigger boat with smaller engine.

 

[alldodge]

Agree, yes they can swap, but check ratio of drives

 

[Bondo]

Agree, yes they can swap, but check ratio of drives

Ayuh,..... Or, just swap the lower units,....

 

[alldodge]

Ayuh,..... Or, just swap the lower units,....

Bravo changes upper and lower to get ratio

 

[Jesse Walter]

Finally had a chance to confirm my gear ratios.

Bravo 1: 1.50-1 with a 19p SS prop
Bravo 3: 2.00-1 with a 23p SS props

 

[alldodge]

Using the lower B3 on either upper will yield a 2.0

Having 23P now will need to prop up much higher unless you get a 15/19 gear set for lower

 

[Jesse Walter]

Using the lower B3 on either upper will yield a 2.0

Having 23P now will need to prop up much higher unless you get a 15/19 gear set for lower

This would be because I have less HP and torque with the 5.7? What pitch props would you recommend?

 

[alldodge]

Need to run the 23's first to see where you are in the rpm range. You might be close

 

[Jesse Walter]

Well I'm going to do the swap and see what happens!

Basically I have 2 of the same boats. I took out the new one only once this summer and I can really tell the difference in control of the B1 vs the B3. Control of the boat is much more responsive with the B3 at slow speeds(docking, etc.). I figured that I might as well swap them. Doesn't really cost me anything.... I've owned the 2004 B3 boat since new so it doesn't owe me anything either.. lol

Just some back story if anyone is interested:

A couple years ago the block developed a crack over the winter. I always drain the water but I suspect that the one way drains on the side of the block are clogged and all the water didnt drain. I JB welded the side and its lasted the past 2 years. The boat actually still runs amazing and doesnt leak water. At the same time the interior upholstery is not in the best shape and I've developed a leak of drive oil somewhere behind the engine that drives me nuts because the bilge gets coated with oil. I suspect that its the 90 deg fitting but I cannot access that area without pulling the engine. Its VERY tight on this model.

This summer I bought the 2006 B1 boat that has very low hours with perfect upholstery. Its almost the same boat with a few upgrades. Only down side is that its not quite the hot rod my 6.2 B3 is.

If the swap goes good I'll probably put the 2004 up for sale. Probably wont get much with a cracked block but thats just the way it goes.

 

[alldodge]

I JB welded the side and its lasted the past 2 years.

There are many boats out there that have been repaired the same way and run without issues.

 

[Jesse Walter]

Finally got the swap done! Took the boat out for the first time today and the outdrive performed great...for the first 15 minutes. Then the engine started to get warm and the alarm went off. I let it cool down for a few and figured out that it would over heat when I went above 2k RPM. I idled back for a few miles and it stayed just about 200deg. Chilled out near the ramp for a while and made it back without needing a tow so I chalk that a success!

I'm going to take off the raw water pump and see if that's the issue. It seems to run good in my driveway with ear muffs but when I rev the engine I get 2 beeps sometimes. I'm thinking the water pressure or flow might be low. I took the boat out one time last year and had no overheating problems but that was with the Bravo 1.

But the Bravo 3 did great! I'll be able to test more once I get the overheating issue taken care of. Hopefully just the impeller need replacing.

 

[alldodge]

I'm going to take off the raw water pump and see if that's the issue.

Most probable cause

 

[Jesse Walter]

Still having the overheat issue. Here is what I've done the past couple weeks:

- First time out engine overheated over 2-3k RPMs. Limped back to ramp at idle at about 180 deg.
- Changed raw water pump to another pump that I just rebuilt. Great water flow. Ran on earmuffs for 20 mins and was at 160 deg.
-2nd time try out. Same problem as first. Stuck close to ramp.
- Checked thermostat. Looked to be in not too good of shape. Thought that might have been the problem. Ran on earmuffs. Great flow, no over heat. Reved to 3k and never got more than 170.
-3rd time try out. Same results as 1 and 2. Took out thermostat at ramp. Still the same issue. Runs 160-180 at idle.
-Changed water pump to new one. Ran on earmuffs for 30 minutes. Let rev a 3k for about 1 minute and temp didnt go past 180. But there is no thermostat. I'd thing that it would run a little cooler.

Haven't tested with the new pump yest. Basically I'm not sold that the pump is the problem. Flow looks really good. I took off most of the hoses and backflushed with the hose. Didnt see anything come out.

I hear guys talking about Bravoitis but when I had the drive off the hose looked super clean. Could I have a manifold problem? Is there a way to troubleshoot that? Could I have a circulating pump issue? How would I check that? Or could there be something in the drive that causes this? Maybe the o ring at the water intake isnt seated correctly letting in air at high rpms? I'm a bit stumped.

 

[alldodge]

This is bravoits and happens in salt mostly, hardly ever in fresh

 

[Jesse Walter]

 

[Jesse Walter]

View attachment Video Bravo.MOV

 

[Jesse Walter]

Doesn't look like I have Bravoitis. Boat did not over heat when I took it out last year with the Bravo 1.