Engine options for Humber Ocean Pro 6.3m

[xpertski]

Hi all,

I currently have a 6.3m Humber ocean pro from 2004. At the time it’s rating was 200hp / 200kg Max. I currently have a 140hp Suzuki, also from 2004, on it weighing probably in the region of 180kg.

New ocean pros of the same model and size are rated to 200hp but the weight allowance has increased to 245kg. Contacting Humber they advised to stay to the original weight limit as the layup may have increased for the new models to take the extra weight.

I’m not looking to change the engine now ... mainly because sufficient £££’s aren’t available right now, but do like the idea of increasing the hp at some stage and had liked the look of 175hp and 200hp engines, mainly to cope better when the boat is full with 4-6 people seated. I was feeling positive that I could when the funds allow make that change but cannot see what engine beyond the current 140 Suzuki that would get close to being under the 200kg weight limit. The new Yamaha 200 is 227kg so close but still over. 175s seem to be based on the larger models so still exceed 200kg. Even the 150hp Suzuki is over the weight.

Any thoughts?

[xpertski]

Reply from Humber with engine weights from 2017 engines it’s not good reading, looks like 140hp is the only option to stay with until technology produces a sub 200kg engine at higher hp than 140. Or buy a newer boat at some stage... don’t particularly think it’s a good idea to go beyond the hull rating ...

140HP
Suzuki 179kg
Yamaha 174kg
Mercury no comparable model
Honda 217kg

150HP
Suzuki 236kg
Yamaha 218kg
Mercury 206kg
Honda 217kg

175HP
Suzuki 232kg
Yamaha 219kg
Mercury 231kg
Honda 270kg

200HP
Suzuki 235kg
Yamaha 221kg
Mercury 231kg
Honda 267k

[Xk59D]

mercury 150 is probably your best bet but it is still just over your limit, i think it is 202kg, check out their website. Unless humber will replate your transom (ask them?) then you may be stuck with it.

Btw don't be concerned about only going up 10hp, the merc 150 will pi$$ all over a suzuki 140 without question, that is one of the "weakest" engines for its HP on market as it is basically a stretched smaller HP motor. the good thing about it is it is light so goes on boats that have no chance of getting a 150 on it.

[Searider]

The 175hp Optimax for sale on this site is less than 200kg......

[xpertski]

Thanks Xk59D, yes I think you are right - definitely something to consider. Might be a couple of years until funds allow for a new motor but maybe by that time either a 150 Mercury or another motor depending on advances by the manufacturers.

Sea rider - yes I like that motor, would buy it now but don’t have the funds, just the wrong timing for me - even next summer may have been a possibility to allow for the potential price of it.

[Xk59D]

if you do exceed the weight best call insurance before you part with your cash to make sure they are happy. it isn't an uncommon thing so they may be okay with it.

[xpertski]

Agree Xk59D. Can’t see they would have a major objection as within a degree of tolerance presumably it’s not really an issue if the weight limit is exceeded slightly (within reason). In addition to the main engine plenty of things add weight to the transom, A frame, towing from U bolts and an Auxiliary which can add 50kg. Suspect, again within reason and not exceeding degree of tolerance, the main issue is the power. Of course if a very heavy engine is on the back which is way over and above the recommended weight then it will adversely affect performance and be unsafe - saw a YouTube video of a 4.5m rib somewhere abroad with a 150hp Yamaha on back, was constantly porpoising and chime walking... scary stuff!

[Xk59D]

yes i have seen the same video, was pretty pointless excersise as couldn't use any of the power, i suspect the weight was more the issue than power as it was quite an angle it was sitting at.

[beamishken]

Originally Posted by xpertski

New ocean pros of the same model and size are rated to 200hp but the weight allowance has increased to 245kg. Contacting Humber they advised to stay to the original weight limit as the layup may have increased for the new models to take the extra weight.

Any thoughts?

That seems a bit vague coming from a manufacturer, surely they know the build spec of their boats both past and present?
Why not go back to them and ask what the diferance is as you would like to upgrade your transom to the later spec
Id susspect the difference is little if anything and me be a simple case of adding extra layup or stiffeners

[xpertski]

Yeah I agree, will go back asking for more detail. I suspect it was someone in sales who responded, will ask if they can get more detail from those involved in the build process. I can’t imagine there is much difference as you say and the difference between a 200kg outboard and one which is 227kg is fairly minor, even less for the Mercury 200hp which is about 216kg.

Will see if I can get more detail from Humber and report back

[xpertski]

Xk59D, yes was a pointless exercise that video, way too much engine (150yam I think?) for that 4.5m boat. Money no sense probably.

[HUMBER P4VWL]

Indeed - the 135/150/175 optimal are all the same block and 196kg

The newer 175/200/225 Merc 4S are just over 200kg. The 150 Merc 4S is under, but also much slower and may be closer to the 140Suz so a pointless swap.

The Opti 150/175 is a great power unit power/weight balance wise on this boat- we should know. [emoji6] 53mph 140L fuel and two up. Tried and tested.

... it’s a steal. Selling as father was 70 this year, had it retubed last winter and he wants to upgrade.

[Last Tango]

Originally Posted by HUMBER P4VWL

The 150 Merc 4S is under, but also much slower and may be closer to the 140Suz so a pointless swap........

The Suzuki 140 is a 2 litre engine, the Mercury 150 4s a 3 litre engine!!

Difference of night and day.

[gpsguru]

Originally Posted by HUMBER P4VWL

Indeed - the 135/150/175 optimal are all the same block and 196kg

The newer 175/200/225 Merc 4S are just over 200kg. The 150 Merc 4S is under, but also much slower and may be closer to the 140Suz so a pointless swap.

The Merc 150 4S is 206kg dry, and takes 6L of oil (0.8kg/L), so nearly 211kg ready to run.

The Merc 150 probably seems so much better than the suzuki 140 due to it being 3L as opposed to 2L, which means the torque band will be very much different with a lot more grunt at lower revs.

In the words of Carrol Shelby .......... "Horsepower sells cars, Torque wins races"

[HUMBER P4VWL]

Originally Posted by gpsguru

The Merc 150 4S is 206kg dry, and takes 6L of oil (0.8kg/L), so nearly 211kg ready to run.

The Merc 150 probably seems so much better than the suzuki 140 due to it being 3L as opposed to 2L, which means the torque band will be very much different with a lot more grunt at lower revs.

In the words of Carrol Shelby .......... "Horsepower sells cars, Torque wins races" [emoji41]

The 195kg optimax has 5litres of oil hanging off the transom in the oil reservoir too though [emoji6]

Suz/Merc but he’s changing from 140, and the Merc 150 4s isn’t an option due to ££

Also, even with a bit more torque, a 150 4s isn’t going to light fires on a 6.3 loaded up. Hence we’re going up to 200hp and 3.4L to try and match the 175 2S

[Jeff]

"The 195kg optimax has 5litres of oil hanging off the transom in the oil reservoir too though [emoji6]"

,,, not if you have the reservoir in the console [emoji6].... [emoji106]

[xpertski]

After much pressing, Humber say this:

I have spoken to one of technical directors. We do not give our specific details of hull layups, for obvious reasons, but they have however confirmed that yes hull layups have changed since your craft was produced in 2004.

They have suggested that you keep within the specified ratings of the craft at point of manufacture.

[Phil and Jane]

Hi, in response, I’ve done six months on a seasonal contract which involved Skippering a Humber Ocean Pro 6.3 which has a Honda 150hp fitted. The engine is too heavy for the boat and every Skipper had the same view. This boat is used for sedate Rib tours coded for a max of ten including one Crew and one Skipper. Even with just a Skipper aboard, the rib did not perform as well as a smaller 5.5 Humber with a 90hp fitted.
I’d not go too heavy if I was you.

[xpertski]

Hi Phil and Jane, I agree, with the rating being to 200kg I wouldn’t have thought going up to around 20kg over would make much difference though? I think the Honda 150 is particularly heavy, 217kg I think for the latest one, older ones presumably heavier. Was it sitting very low at transom with that weight and struggling to get over the hump?

If possible my thoughts when replacing my engine would be to see if a 175hp or 200hp could get close to the weight limit or just below - all current engines are just over, without going two stroke like an Optimax. Perhaps need technology to take another step and start producing sub 200kg 200hp outboards!

[Xk59D]

i hope they don't get lighter, they are pulling metal out them to do it, only so far you can go before you literally have chuckable engines, to be fair these modern engines imo won't last as long as old 2 strokes, i think we have got a lot more reliability now but not longevity perhaps, modern 2 strokes if anything are worse!