3.1m suzmar with single skin hull

[iaind]

Hi can anyone help.I have a 3.1 Suzmar rib with a single f/g hull.It says it can take a 15hp 4 stroke engine which weighs 46kg.I have just had our 15hp engine stolen(great) and have purchased a 2 stroke 25hp weighing 47kg.
Do you think the boat will be ok useing a 25HP.Has anyone done anything like this??

[simmons0]

In our experience a 25 2/s on tiller on a 4m inflatable was fun but a handfull. On a 3.1, you'll have to be careful put it that way!

[codprawn]

Go for it - I use a 15hp 4 stroke on a 3.1m sib and it's fine - yours will go like stink.

As Simmons says though watch the throttle!!! Keep your eye on the transom though - it could twist with the power.

If you think that's a load of power remember the new Avon and williams jet RIBs are the same size with 105hp............

[Richard B]

You're going to need a lot of caution with this rig! The torque of the 25hp motor on a tiller steer will wrench sideways with a lot of force if you open it up and it all depends on where you use it... if you use the boat in rough water watch your speed as 3.1m boats fly in a swell. Just make sure that you never, ever drive without the kill cord attached.

[codprawn]

RNLI use 40hp tiller steered and the zapcats are 50hp so a "puny" 25hp can't be that bad!!!

[Richard B]

1. They are both bigger than 3.1 m
2. You've tried them yourself?

[codprawn]

Originally Posted by Richard B

1. They are both bigger than 3.1 m
2. You've tried them yourself?

Yes had a brief go in a D class - great fun but they put lines/ridges on the tubes to force you to kneel instead of sitting on the tubes - most uncomfortable!!!

Anyway the size of the boat has nothing to do with tiller steering.............

[Richard B]

It's got a lot do do with the stability of the whole rig though. V short boats will steer very sharply with tiny tiller movements and can be very disconcerting at first. Zapcats have "rails" on the base of each tube so they are hardly comparable with a shallow V hull. Did you push the D-class to the limit in a choppy sea and take off over some swells?

[simmons0]

Originally Posted by codprawn

RNLI use 40hp tiller steered and the zapcats are 50hp so a "puny" 25hp can't be that bad!!!

The D class is 5m long and weighed down with 3 blokes and a lot of kit and the Zapcats are a different breed altogether.
Personally I think 25hp is too much for a family boat, you'll have to be so careful on the throttle, particularly if your on your own. But give it a go, just be cautious.
And if you let anyone else drive, especially if they haven't used a tiller throttle before make sure they know if they are too heavy handed you'll all be in the drink.
H

[Stoo]

And there's the issue of insurance. If the motor is over the rating on the plate, and there's a problem, so long coverage!

[codprawn]

Originally Posted by Richard B

It's got a lot do do with the stability of the whole rig though. V short boats will steer very sharply with tiny tiller movements and can be very disconcerting at first. Zapcats have "rails" on the base of each tube so they are hardly comparable with a shallow V hull. Did you push the D-class to the limit in a choppy sea and take off over some swells?

I didn't get anywhere near the limit of the D class considering the RNLI mechanic told me he once took it out in a Force 12 to recover the crew of the all weather boat which had engine problems.

We did have some fun in the rough stuff though - strange feeling as it bends over the waves which a RIB obviously doesn't do!!!

[ribfan]

Years ago I had a 12.5 ft Dynous SIB with a 25 HP Yam. It went well and fast. The rig had tiller steering. The boat handled well, although the steering was very tight.

Only problem was with the front floor board cracking from hitting waves. After re-enforcing boards, no problems, so excercise care, but have fun!

www.eclecticwonders.com uncommon art