Speed question.

[Cliff B]

Hi guys

Do and of you experienced SIBers know roughly what sort of speeds I should expect to see one or two up in my Honwave T40 AE (aluminium floor) with the Tohatsu 18 4 stroke with just fuel and a few odds and sods on-board (not much weight).

Thanks in advance (I know this question must be boring for some of you long termers)

Cliff

[chipko]

Somewhere between 18 to 20 knots I would imagine.

[Fenlander]

I'd agree with Chipko Cliff... I've had a variety of SIBs with 15hp-20hp OBs and as long as the load's not excessive pretty well everything has fallen into that 18-20kt range.

The other thing I've found is there isn't a huge difference between a 15 and 20hp motor on top speed but the extra grunt of the 20hp mid range is noticeable when working the waves. Of course you are smack bang in the middle of that HP range so you should be in the mentioned speed range.

Not sure if you are aware your Tohatsu 18hp is one of the holy grail OBs for SIBs... there's the Tohatsu 9.8hp 2-stroke, Yamaha/Mercury/Mariner 15hp 2-strokes and yours. Some of the best portable OBs for 3m-4m SIBs.

[69cmw]

Originally Posted by Fenlander

Not sure if you are aware your Tohatsu 18hp is one of the holy grail OBs for SIBs... there's the Tohatsu 9.8hp 2-stroke, Yamaha/Mercury/Mariner 15hp 2-strokes and yours. Some of the best portable OBs for 3m-4m SIBs.

What is so special about a twatsoo 18HP 4 stroke?

[Cliff B]

Thanks guys. They are the figures i was expecting, the reason I asked was I've seen a couple of you tube videos where people have hit high 20's even 30kts. I'm still hoping I'll hit those outrageous speeds 😂😂😂😂

[Fenlander]

>>>What is so special about a twatsoo 18HP 4 stroke?

Ahh good spot. Ever since Cliff's first post my mind went straight to the thought his was the 18 2-stroke, which is a much in demand motor. Nothing wrong with the 4-stroke though... just a bit heavy for a daily inflate like we do.

Re the 30kts Youtubers Cliff. Are you sure that wasn't km/hr if on a SIB? Also ignore any speed results when the OB is on a light hard hull... much more speed with them than a SIB.

[Landlockedpirate]

I had a T40 with a 25, it didnt hit anywhere near 30kts. Chipko is on the money at 18 to 20kts.

If you want 30kts+ in a sib, you need to be looking at a big engined Futura.

[Cliff B]

I was only joking about hitting those sort of speeds. When I had my little speed boat with a 55 on the back I only used to hit just over 40kts , so know it's not achievable. 20ish as a maximum with the wife and nippers is what I got the sib for.

[Max...]

20 might be pushing it with that load but 18 for sure.

[beerbelly]

my old futura fastroller with 25 Yamaha would do 30 knts on a flat Scottish loch it was a bit scary but fun at the same time