If not a spun hub, then what?

TickledPink

So, as you know, I'm still learning about all this boat stuff. I haven't picked your brains for a while but I definitely need some advice now.
I have high revs but low speed. Researching this ,I figured it's a spun hub. OK, cheap enough and easy to replace. 
But now I've read that the Bravo 3 has no hub, so what is damaged? I can see this being expensive 😳

PickleRick

Hopefully it's your shift cable isn't fully engaged but it could be time for a tear down as the clutch cone is worn/slipping 

PickleRick

SEI now has bravo 3 upper and lowers, not sure of their quality.  The alpha they offer has good reviews....for an alpha.   The pricing is good vs Merc. Might be worth looking at if you determine it's an internal issue and not a shift cable issue 

aero3113

It could be your engine coupler.

PickleRick

Ouch if it's a coupler.  I am pretty sure I can see the rubber bushing on mine by sticking a cell cellphone back there but on a V8 that's going to be hard.  And if the splines themselves are gone you'll have to pull the drive to inspect. 

aero3113

If you can reach, put a paint stripe on the housing and rubber part of the coupling. Run the engine and put it in gear then back to neutral then shut off. Check if the paint mark is still aligned.

YYZRC

What pitch are the props?

aero3113

Yea, I guess we should’ve asked what revs and speed you’re getting…?

captkevin

Knowing exactly what you are getting for low speed / high revs would be helpful

PickleRick

They wanna know if your hull below the water line looks like a chia pet or has more barnacle than the flying Dutchman 

rasbury

Coupler is not to terrifying ..out drive off and motor pulled forward but probably not out..

TickledPink

The revs go up to 3.5 and the max speed is 8mph 

TickledPink

I'm having the engine pulled out in the new year. Hopefully that will make it easier to fix.

TickledPink

YYZRC said:

What pitch are the props?

22

TickledPink

PickleRick said:

They wanna know if your hull below the water line looks like a chia pet or has more barnacle than the flying Dutchman 

The hull has been cleaned up. It made no difference. 

TickledPink

PickleRick said:

SEI now has bravo 3 upper and lowers, not sure of their quality.  The alpha they offer has good reviews....for an alpha.   The pricing is good vs Merc. Might be worth looking at if you determine it's an internal issue and not a shift cable issue 

I'm on the Isle of Wight UK. I hope I can get a good price here.

YYZRC

How old are the plugs/wires/cap/rotor?

PickleRick

3500 isn't high revs, I'm not sure what V8 you have but 4500 to 5500 would be in your WOT range. 

3500 means you're not getting enough rpms or power.

As @YYZRC mentioned you could just need a good tune up. 

Before pulling the engine get it to normal running temperature and pull all the plugs to do a compression test.   

Keep the plugs labeled as to which cylinder each one came out off for a visual inspection,  plug color tells a lot about an engines running condition.

Formulaben

TickledPink said:

PickleRick said:

They wanna know if your hull below the water line looks like a chia pet or has more barnacle than the flying Dutchman 

The hull has been cleaned up. It made no difference. 

What do the props look like?  It doesn't take much for cavitation to kick in and you'll go nowhere fast.

YYZRC

He’s only hitting 3500 rpm. If the props were cavitating he would be at redline. 

TickledPink

YYZRC said:

How old are the plugs/wires/cap/rotor?

No idea. I bought the boat in January 23. Used it 3 times and then lost performance. I got a mechanic to look at it and he found a shed load of things wrong, including a sticking starter motor, leaking transom shield (looks like steering pivot seals), exhaust risers leaking externally, rusty pulleys, bilge pump breaker keeps popping, lots of rust.
With all that in mind, he wants to pull the engine out to see if there's anything else that he can't see, 
All in all its turned out to be a money pit but I'd rather get it all fixed up than get rid of it.
A part of the skeg is broken off too but that was done after I bought it. I don't recall hitting any rocks or anything but it's a weld job.

TickledPink

TickledPink

TickledPink

Before the skeg break.

YYZRC

Not sure I see the point of pulling the engine. It's a very time intensive job. It sounds as though you haven't yet investigated the simple/common maintenance items.

I would replace the cap/rotor/plugs/wires as a first step. Couple of hours of relatively easy work not terribly costly in boat terms at about 500 quid.

I wouldn't worry about the skeg, it is not an urgent repair by any stretch. At only 8mph you aren't going fast enough to derive any benefit from it!

captkevin

What size/weight is your boat? 5.0 mpi is not alot of power for a cruiser. With a heavy load not surprising it would struggle to get on plane. What pitch are the props? Might be time for Hill 4x4 upgrade.

YYZRC

TickledPink said:

Based on this pic, I would drill a 1/2" or larger hole in the inside transom as low down as you can and just through the inside layer of fiberglass/gelcoat into the plywood. Those rust stains on the starboard side are interesting.

LaRea

YYZRC said:

Based on this pic, I would drill a 1/2" or larger hole in the inside transom as low down as you can and just through the inside layer of fiberglass/gelcoat into the plywood. Those rust stains on the starboard side are interesting.

Hah -- I thought you were going to say drill it all the way through!  But yes it does look like the transom is probably full of water.  

(BTW the blower needs another section of 4" duct that extends down into the bilge.  You want the blower pulling air from the lowest point, which is where gas fumes would end up.)  

TickledPink

YYZRC said:

TickledPink said:

Based on this pic, I would drill a 1/2" or larger hole in the inside transom as low down as you can and just through the inside layer of fiberglass/gelcoat into the plywood. Those rust stains on the starboard side are interesting.

No idea what those vertical rust stains are. Very random.

TickledPink

LaRea said:

YYZRC said:

Based on this pic, I would drill a 1/2" or larger hole in the inside transom as low down as you can and just through the inside layer of fiberglass/gelcoat into the plywood. Those rust stains on the starboard side are interesting.

Hah -- I thought you were going to say drill it all the way through!  But yes it does look like the transom is probably full of water.  

(BTW the blower needs another section of 4" duct that extends down into the bilge.  You want the blower pulling air from the lowest point, which is where gas fumes would end up.)  

I've bought the duct so I'll get that put on 🙂

TickledPink

captkevin said:

What size/weight is your boat? 5.0 mpi is not alot of power for a cruiser. With a heavy load not surprising it would struggle to get on plane. What pitch are the props? Might be time for Hill 4x4 upgrade.

It's an FV 250. Length is 27.23ft and beam is 8.5ft. Weight is 2.8 tonnes.
I'd like to get the Hill 4x4. Not sure I can get it over here but I'll do some googling.