School me on 450R’s….

[THE Cat Sass]

So here‘s my story. Long time performance boater - blower motors, whippled motors, bunch of nitrous…had ‘em all. Figure it’s time to jump on this outboard bandwagon as 125 is fast enough and I’d rather boat than wrench on shit. Been there, done it. My prior 2 boats had a 550 Ilmor and twin Merc 600SCI’s respectively and honestly they were reasonably bulletproof (although the Ilmor had 160 hours and the Merc’s 60 hours) when I sold those boats.

Fast forward and I made the move to a twin 450 cat and took delivery in November. It sat in my garage for a couple months and I figure it’s time to swap the fluids to prep for that elusive warm spring day we occasionally get in the PNW. Upon draining both lowers I immediately see heavy contamination with water. Way worse on the STBD side but still some water in the PORT side.

Luckily they are ’21 motors so the warranty is intact but here’s my question. When digging into the motors brief history I find out there was already a warranty claim for a leaky shaft seal on the STBD side motor and just a month or so prior to me taking delivery. Now it‘s leaking again as well as the other side. It’s also smoked a prop shaft on the STBD side.

So what’s your history with your 450’s? I’m not knocking them, I have about 35 minutes of seat time and I love ‘em. I’m sold, just curious what others with a few more hours have seen.

 

[4Waters]

There's another thread about this that started in the last couple of weeks @Bullhead bully had some information on what happens (vent or lack of if I remember correctly)

 

[THE Cat Sass]

Yeah, that may have been my initial post, not certain. Just looking to expand upon others experience with them. For that specific issue of shaft seals failing during contraction I think his fix is the only solution really. Unfortunately thats a post warranty type of program.

 

[77charger]

Know a merc mechanic he said lot of problems with leaking and shaft breaking,We were talking outboards for ocean and he mentioned this.

 

[Doc]

There have been so many revisions to current Merc Outboard prop shafts including seals from what I know. I would call Barrett Marine and see what he can do for you under warranty as he's no rookie to these motors.

 

[SJP]

I did not see in your other posts what hull you are pushing with these. Does it roll over smooth and effortlessly? There are certain boats that have been more prone to snapping shafts. Is there any shuddering, cavitation, or vibration when coming off plane? It could also be how the previous owner drove it lending to issues.

 

[MK1MOD0]

Offshore only has a ton of info regarding the 450 and it’s issues. Prop shafts seem to be more affected on cats with high prop shaft heights. The guys running surfaces props seem to have many more issues than those that don’t, such as a center console.

 

[HBCraig]

Are there solar issues with the 400's?

Just curious

 

[RiverDave]

Know a merc mechanic he said lot of problems with leaking and shaft breaking,We were talking outboards for ocean and he mentioned this.

The shafts were the earlier 400’s. Not sure if that affected the 450’s

 

[77charger]

The shafts were the earlier 400’s. Not sure if that affected the 450’s

He told me he’s seen them on 450s too. But I guess if you have warranty why worry problem will get solved.

 

[THE Cat Sass]

Boat is a DCB M33R. It's already eaten a prop shaft and I'm guessing it started off with a reasonable amount of cavitation getting on plane as it eventually had a center tab added. My guess is that contributed to the prop shaft dying. Mine was one of the earlier M33's and I don't see many with tabs so they likely figured the set up out on later models. I run Merc Racing 36's - 18 rake and 15" diameter props.

I've driven it one time for all of 40 minutes and only rolled it on plane a couple times. I had maybe 2 seconds of cavitation but I know the sequence now and I'm confident in a couple more attempts I'll get it over with zero cavitation. It's interesting as I've watched about 100 Desert Storm boat vids and some of the 450R boats have crazy cavitation and for it seems like forever when they get on plane. That shit freaks me out...doesnt feel right so I'm going to avoid it at all costs.

 

[prorider]

Boat is a DCB M33R. It's already eaten a prop shaft and I'm guessing it started off with a reasonable amount of cavitation getting on plane as it eventually had a center tab added. My guess is that contributed to the prop shaft dying. Mine was one of the earlier M33's and I don't see many with tabs so they likely figured the set up out on later models. I run Merc Racing 36's - 18 rake and 15" diameter props.

I've driven it one time for all of 40 minutes and only rolled it on plane a couple times. I had maybe 2 seconds of cavitation but I know the sequence now and I'm confident in a couple more attempts I'll get it over with zero cavitation. It's interesting as I've watched about 100 Desert Storm boat vids and some of the 450R boats have crazy cavitation and for it seems like forever when they get on plane. That shit freaks me out...doesnt feel right so I'm going to avoid it at all costs.

Your boat came with 400s first. Brad had Dcb repower it with 450s. They added the tab then. Lots of shaft’s breaking.

 

[Warlock1]

Boat is a DCB M33R. It's already eaten a prop shaft and I'm guessing it started off with a reasonable amount of cavitation getting on plane as it eventually had a center tab added. My guess is that contributed to the prop shaft dying. Mine was one of the earlier M33's and I don't see many with tabs so they likely figured the set up out on later models. I run Merc Racing 36's - 18 rake and 15" diameter props.

I've driven it one time for all of 40 minutes and only rolled it on plane a couple times. I had maybe 2 seconds of cavitation but I know the sequence now and I'm confident in a couple more attempts I'll get it over with zero cavitation. It's interesting as I've watched about 100 Desert Storm boat vids and some of the 450R boats have crazy cavitation and for it seems like forever when they get on plane. That shit freaks me out...doesnt feel right so I'm going to avoid it at all costs.

It appears in a later response your boat was a refit with the new engines. If they have found a better position for those engines, maybe look into taking it back and having them rehang the engines in a more optimum spot instead of trying other means to fix the issue. In my brain fixing the root cause is way better than spending money and time to figure out a band-aid for an issue.