Engine performance

[Gilly65]

Thank you very much. The figures have helped me make up my mind. I think i will be going for a 6 hp As mostly I will be on my own and portability is key and I will not be going out more than a mile so i should be able to get back to shore fairly quickly if the weather turns.

[neil h]

Personally I think you should search for a nice Tohatsu 9.8 two stroke, at only 26kg

[Martin]

There’s an age old argument about power/speed etc, it raises its head from time to time in here and various other places. Gurnard & Douglas are two fairly light weight gents, I have no idea of your weight/build but I do think that even considering two people up at sea even just kids - and a 6hp, I’d advise against it.
I’ve stayed off this thread upto now, tbh ..I think your making a big mistake with a 6hp and if it was mine I’d be looking for a 9.8/9.9hp motor.
Just my 2p, bit you can’t have too much power when the wind and tide are against you.

[warder54]

A much better match

I agree with Martin here. Danny and myself were out in a 3m sib some years ago with a 5hp (Seagul) the performance was abysmal, the weather changed and sea got up, we were less than 1/2 a mile out. As we approached the harbour entrance we lost steerage as the motor couldn't move us as fast as the now following seas were pushing us. By pure luck we were lined up perfectly and surfed into the outer harbour at Arbroath. That Outboard went up for sale next day. A few Car Boot sales later we had a nice Yam 5 on the back. I'll never under power again!

[sparerib]

Martin and Warder54 have pretty much nailed it, performance if you need it at a weight that you can manage !

[Gilly65]

Thank you for your comments. My next question will be , what would a 9.9 4 stroke be like on a f rib 360. My thinking is if i have the extra weight for an engine i might as well have a slightly bigger boat. Or would I be back to square one where a 9.9 hp would not be quite suitable for a 360. This is so confusing and I respect your thoughts

[DouglasW]

Hi Gilly, first of all I have been 15 stone for most of the time I have had the F-Rib 330 and The Gurnard is heavier than I am. I have 3 engines for my F-RIB 330 Suzuki 2.5, Yamaha 6 and Yamaha 15 and have also tried my friends 9.9 so I have no particular axe to grind regarding what size is "best". I use my boat on an exposed coastal location open to the prevailing SW winds. The spring tidal range is 9m and the spring rate is 4 knots with more round the headlands where there are tide races and overfalls.

These are my GPS tracks from the last two seasons. Light blue is Suzuki 2.5, dark blue is Yamaha 6, dark grey (just a few) Suzuki 9.9 and green Yamaha 15. Obviously going out as often as I do you encounter bad weather. I have never experienced a problem with the 6HP not having enough grunt. Indeed the few scary moments I have had in rough water have been when I have applied too much power with the 15. In rough water both I and Gurnard seldom use full throttle with the 6 never mind the 15.

I would say that of the 4 engines I have tried with the F-RIB, the two best all rounders are the 6 at 27kg which will plane the boat with one big adult and the 9.9 at 39kg which will plane the boat with two big adults. The advantage with the 6 is that it is very portable and manageable by one person ashore. The 9.9 is significantly heavier and less portable especially if most of your boating is on your own.

The F-RIBS are great wee boats and although they are capable of going fast they are not comfortable speed boats in anything but calm water. I have tried the 275, 330 and 360 and top speed on each is limited by how much of a bashing your body is capable of taking. Powered by the 15 the bashing is worse with two or more people aboard and planing at a particular speed than it is with just one aboard. I never operate at anywhere near top speed with passengers aboard, if there are even small waves.

Think carefully about what you want out of your boat. If portability is your prime priority then the 6 would be best. If speed with two up is your priority then a 9.9 would be best. You might be like me and end up with more than one engine...perhaps a 2.5 and a 9.9? If you look at the GPS tracks the light blue Suzuki 2.5 trips are mostly trips out round the exposed sides of the islands a distance of 14-15km. Most of them were two up with my wife. We were not planing but we had fun.

I have shown these tracks to demonstrate the experiences with each size of engine through which I have reached my opinions. I wish you much fun with your new boat.

Douglas

[Martin]

Hi Gilly65 ..nice choice in boat ..my brother has the 330 and I have the 275 size

I have a 6HP on mine ..I weight 196lb ..and with fishing gear and lunch ..on my own..it happily goes around 15 mph. With myself and full camping gear..it wont plane unless I use a smaller pitch prop..but them it planes around 10-12 mph

Hi Gilly, first of all I have been 15 stone for most of the time I have had the F-Rib 330 and The Gurnard is heavier than I am.

Douglas

Not confrontational in the slightest, but if i'm correct, your figures don't add up Douglas..
196lb is 88.9kg or 14 stone

Gilly, be very wary of the quoted weights and speeds from f-rib website, they have been proven misleading at times.
If you want specifics on the boats you'd be as well asking the guys that own the boats if they have weighed them.


Regards,
Martin

[DouglasW]

Hi Martin, I was 15stone 4lbs when I got the F-Rib in April 2016 but am now 11 stone 4lbs due to a progressive medical problem. The Gurnard has also put on weight over the same period due to another medical problem. I did keep a note of my weight at the times when I did each of the speed tests.

Some more figures: over the 2 seasons of ownership of the F-Rib 330, I have launched it 362 times and covered 3,664km. The combination of the 2.5, 6, and 15 motors did most of that, (each seeing about a third of the total) and the 9.9 only 97km. That 3664km is equivalent distance from London to Newfoundland. It sure was a heap of fun and I feel I have got a decent insight into the boat and the motors.

I am pretty sure Gurnard will have covered a greater distance than that in his 275/6HP combination because I also windsurf, sail and kayak which limits my time in the F-RIB. I mostly operate mine from the one location on the Solway but the Gurnard has used his extensively round some pretty remote islands and headlands in the far NW. As far as I know he has never felt underpowered one up with the 6HP. I do like the power of my 15HP but it has only been off the beach for its first services.

Looking at it another way, perhaps there is an inverse correlation between boat/engine size and weight and distance covered? The smaller and more portable the boat/engine, the more likely you are to take it out and rack up the kilometres!

Douglas

[mattswan2512]

I have a 330 as ive previously said and i borrowed martins 1970 sonething (i think) suzuki 9.9.....in scotland and i was faster than a honwave with a 15 on the back and that was with a spatk issue too...dont go under 9.9 hp or you will not be happy.....why struggle with power and fast current if you dont need too....i promise you 9.9 will deliver what you need and more with a 330....

I get light is portable but thet are manageable at 10hp just get 2 stroke as they are sooooooo much lighter but yes granted a bit more thirsty.....