Switch to full style
Soft Floor Inflatable Boats
Post a reply

Speed Freak :-)

02 Jul 2017, 19:12

Went to Ullswater today for my second outing! It was quite windy, very choppy and packed full of sail boats...I changed the oil in the OB midweek, I say I did, a cousin did it for me. There was 900 ml of the old stuff instead of 600 ml, not sure how much of a difference that makes, but the old oil was pretty mucky...I had the keel at the correct pressure today which made a huge difference. I went as far as I could towards all the sail boat at a steady 8 mph, this was heading into the chop and wind, I then turned cutting across and hit 15 mph at one point but averaged 13 mph, so was very very happy...

The only bad point was the bloody valve I bought for the Bravo from the Marine Store. I partially inflated the tubes before putting the floor in. Inflated the floor, and then went back to inflate the tubes. Both ends of the valve completely snapped off, the plastic seems to be very very brittle...The hand pump supplied with the boat came with two corrugated pipes, it turned out that on the larger one the valve unscrews, but only has a lip of around 5 mm to fit the pipe from the Bravo. So once the valve was inserted it was a case of holding the pipe on to the valve, pain in the butt but got the job done...
Valve Broken.jpg

Re: Speed Freak :-)

02 Jul 2017, 20:20

Average of 13mph with that 6hp is awesome going, especially for the size of the sib, at least it appears to be performing somewhat better than previously ,
I would have thought 900ml of oil would not be doing it much good, if it's supposed to only have 600ml it may be part of the reason why the performance was poor before

Re: Speed Freak :-)

02 Jul 2017, 20:56

Hello Paul :D Our lass said it sounded less muffled, hard for me to judge because of my hearing...She also said the bow was up a lot more due to the keel pressure. All I know is it was really good fun, even if a little choppy :D

Re: Speed Freak :-)

02 Jul 2017, 21:05


Good to hear that a wee bit of fine tuning is paying off mate :thumbsup
These small boats can be very 'tetchy' and the finest of 'tweeks' make all the difference :!:
Glad your 2nd voyage went well mate :drive

Re: Speed Freak :-)

02 Jul 2017, 21:43

Thanks Paul :D Something I forgot to mention. I was really surprised that it doesn't have an oil filter, I know very little about engines but I did think they all had oil filters!

Re: Speed Freak :-)

02 Jul 2017, 22:28

13mph, not bad mate.

Re: Speed Freak :-)

02 Jul 2017, 22:40

That's cracking stuff Pete.. :thumbsup

The oil situation wont have helped much, but i can't for the love of god think it'd cause you the speed problems you had.
I'd be tempted to put it down to keel pressure and the carb strip & clean i did for you buddy...

Main thing is, you increased your speed... :clappy
And i guess it got properly onto the plain then ? :drive :yay

Re: Speed Freak :-)

03 Jul 2017, 10:07

You alright fella :D I don't remember you stripping the carb, I know you took it off and said it looked alright, but then I was doing a lot of japping :D
Keel pressure had a BIG effect for sure, but I put it down to my secret weapon, the tank was half full so I topped up with Super Unleaded :D
I think a combination of things has made a vast improvement, certainly was a lot of fun though, be interesting to see how it performs in calmer conditions.

Re: Speed Freak :-)

03 Jul 2017, 10:25

Be careful with the super fuel Pete. The octane rating is a fair bit higher and your engine won't be designed to run on it.
Your manual will tell you which to use.

Re: Speed Freak :-)

03 Jul 2017, 14:40

Hi Pete, that is a great speed to get from such a small outboard. :)

I run my Yamaha F6C outboard on my F-RIB 330 on premium petrol and have done so for over 100 outings. It runs just great. The manual only stipulates a minimum of 90 RON. Both the Yamaha certified dealer where I bought it and the Yamaha certified dealer where I get it serviced recommended premium petrol as it keeps the carbs clean and runs smoother. Unfortunately none of the petrol stations near where I keep the boat stock premium so I need to bring it from Glasgow. Last year when I ran out I had to use local regular grade petrol. I found the engine more difficult to get onto the plane and it would not reach max revs at full throttle with the standard prop and one person aboard and my maximum speed was 23km/hr. Using premium petrol the motor does hit max revs at WOT and consistently gives 25-27km/hr at WOT (depending on sea state) that's about 16-17mph.

My uncle has a 40 HP Suzuki four stroke on his RIB, which is 8 years old and has 550 hours on it. He was advised by the Suzuki dealer to run it on premium petrol because it would run smother and start better. At the beginning of each season it starts first press of the button.

Based on this experience I will continue to run mine on premium.

Post a reply