Mercury 450R - any issues ?

[McKay]

I'm interested if Mercury will allow the new motor mounts to be installed if the current units haven't failed. Mine seem fine, but I feel the same way, I'd like to get them replaced before my cowls get beat to shit because the mount fails.

Have you found any data on prop shaft failure rate with the updated "Rev B" shafts? I know you have had good luck with yours and been running it heavy and hard.

I have not heard of anything first hand on the Rev B's breaking.

 

[TVMNick]

Just broke my second shaft last month. So that makes both motors now. Around 140 hours on mine. Also lost a alternator.

What boat are you running? I was really surprised at how easily the shaft broke, my motors were produced 08/20 so they were prior to the Rev B shaft.

 

[prorider]

What boat are you running? I was really surprised at how easily the shaft broke, my motors were produced 08/20 so they were prior to the Rev B shaft.

28 Speedster. I baby it till it’s on plane. Not convinced anything but a larger shaft is going to eliminate the problem.

 

[TVMNick]

28 Speedster. I baby it till it’s on plane. Not convinced anything but a larger shaft is going to eliminate the problem.

I'd be interested in an aftermarket shaft if someone builds something stronger, I wish we could get the stress/strain data for the current shaft so we have a basis to compare to.

I do the same thing now, I baby mine onto plane and I'm running lower pitch props to help reduce strain. My boat will plane with no cavitation on my lower pitches, so that is what I will continue to do. Mercury warrantying the failed shafts is good, but it still sucks because you lose your time, and generally they fail in an inconvenient location.

 

[KingofBeers]

I'd be interested in an aftermarket shaft if someone builds something stronger, I wish we could get the stress/strain data for the current shaft so we have a basis to compare to.

I do the same thing now, I baby mine onto plane and I'm running lower pitch props to help reduce strain. My boat will plane with no cavitation on my lower pitches, so that is what I will continue to do. Mercury warrantying the failed shafts is good, but it still sucks because you lose your time, and generally they fail in an inconvenient location.

Im not sure its a question of building a stronger shaft. Ive spoke to a number of people about this issue as I went through 3 shafts on an early 300r. One of which was the most updated 450 shaft. The consensus was that there simply isnt enough shaft support due to needing a bunch of room for exhaust to exit. If the bearing carrier could be made larger they may last. Think about the lowers on big inboards, those boats are way heavier making waaaay more power. Difference is they have a ton of bearing area to support the shafts. Sure the shafts are larger, but it is proportional to the amount of torque they are sending though it. Maybe I dont know what im talking about, but ive talked to some of the big drive builders seeking advice as well as a couple people at Merc and they seem to be saying the same thing.

I got lucky on the 450 shaft as it broke way inside the case the second i cracked the throttle to get on plane and I somehow didnt lose my prop. Oh, and Merc told me to pound sand on the last one because my boat "wasnt rigged properly".

 

[TVMNick]

Im not sure its a question of building a stronger shaft. Ive spoke to a number of people about this issue as I went through 3 shafts on an early 300r. One of which was the most updated 450 shaft. The consensus was that there simply isnt enough shaft support due to needing a bunch of room for exhaust to exit. If the bearing carrier could be made larger they may last. Think about the lowers on big inboards, those boats are way heavier making waaaay more power. Difference is they have a ton of bearing area to support the shafts. Sure the shafts are larger, but it is proportional to the amount of torque they are sending though it. Maybe I dont know what im talking about, but ive talked to some of the big drive builders seeking advice as well as a couple people at Merc and they seem to be saying the same thing.

I got lucky on the 450 shaft as it broke way inside the case the second i cracked the throttle to get on plane and I somehow didnt lose my prop. Oh, and Merc told me to pound sand on the last one because my boat "wasnt rigged properly".

I can definitely see what you are saying with the bearing support, the torsional load could cause significant stress in the shaft causing failure no matter the strength of the shaft material.

Hopefully Mercury addresses this on the 500 and I can just re-rig my boat to those

 

[Duramax]

Im not sure its a question of building a stronger shaft. Ive spoke to a number of people about this issue as I went through 3 shafts on an early 300r. One of which was the most updated 450 shaft. The consensus was that there simply isnt enough shaft support due to needing a bunch of room for exhaust to exit. If the bearing carrier could be made larger they may last. Think about the lowers on big inboards, those boats are way heavier making waaaay more power. Difference is they have a ton of bearing area to support the shafts. Sure the shafts are larger, but it is proportional to the amount of torque they are sending though it. Maybe I dont know what im talking about, but ive talked to some of the big drive builders seeking advice as well as a couple people at Merc and they seem to be saying the same thing.

I got lucky on the 450 shaft as it broke way inside the case the second i cracked the throttle to get on plane and I somehow didnt lose my prop. Oh, and Merc told me to pound sand on the last one because my boat "wasnt rigged properly".

View attachment 1071309

How in the hell was your boat not, "rigged correctly"? Also, I had a bunch of problems with a timing sprocket on a turbo charged VW Caddy years ago. I finally took my third new sprocket and sent it back east to get a Cryogenic treatment done. Never had a problem again and ran way more boost than I originally did.

Maybe an option?

 

[KingofBeers]

How in the hell was your boat not, "rigged correctly"? Also, I had a bunch of problems with a timing sprocket on a turbo charged VW Caddy years ago. I finally took my third new sprocket and sent it back east to get a Cryogenic treatment done. Never had a problem again and ran way more boost than I originally did.

Maybe an option?

My boat is not rigged properly because they dont have a solution to prop shafts breaking. Even the high dollar, state of the art hulls like Skater, MTI, DCB, etc are eating propshafts. Dont tell me that a brand new right off the showroom floor MTI 340x isnt rigged properly. But, not gonna win a fight with mother merc so wtf do you do?

I had called my old 4 wheelin buddy that runs a fab shop/machine shop up in Lincoln, CA about cryo treating a shaft to see what happens but I never followed through with it. He had done some toyota 8" gearsets for me back in the day that lived through numerous snapped axles and a grenaded detroit before being replaced with D60s. I think when im done throwing money at the Skater im going to put a Porta-Bracket on the Liberator. Getting the prop deep to get out of the hole is the answer I think even though im not much of a fan of hydraulic jackplates.

 

[Duramax]

My boat is not rigged properly because they dont have a solution to prop shafts breaking. Even the high dollar, state of the art hulls like Skater, MTI, DCB, etc are eating propshafts. Dont tell me that a brand new right off the showroom floor MTI 340x isnt rigged properly. But, not gonna win a fight with mother merc so wtf do you do?

I had called my old 4 wheelin buddy that runs a fab shop/machine shop up in Lincoln, CA about cryo treating a shaft to see what happens but I never followed through with it. He had done some toyota 8" gearsets for me back in the day that lived through numerous snapped axles and a grenaded detroit before being replaced with D60s. I think when im done throwing money at the Skater im going to put a Porta-Bracket on the Liberator. Getting the prop deep to get out of the hole is the answer I think even though im not much of a fan of hydraulic jackplates.

You will never be done throwing money at the Skater....=)

 

[KingofBeers]

You will never be done throwing money at the Skater....=)

Lol...you are probably right about that.

 

[HST4ME]

If there was another support bearing right behind the reverse gear this would probably tame down the issue.

 

[lake p.a.l.]

You will never be done throwing money at the Skater....=)

None of us idiots will ever be done throwing $$ @ floating money pits that we love.........