Rib jet

skovmand · 30 May 2015, 21:52

Problem steering

I have had My weedo 22d in the sea for the first time

But I have a problem with the steering it is almost impossible to sail it in a straight line.

It Will go from side to side the hole time .

Any one that have an idea with this ?

Best regards
Jesper Denmark

willk · 30 May 2015, 21:56

Excuse me for asking, but have you driven a "jet" before?

skovmand · 30 May 2015, 22:01

No i have not it is the first time ever thats why i thought that some one here could help 😉

willk · 30 May 2015, 22:12

Quote:

Originally Posted by skovmand

No i have not it is the first time ever thats why i thought that some one here could help ��

Ah, OK. They don't drive like prop boats. You will either have to play about with it or get someone with jet experience to show you the technique. It's not difficult, but it's not intuitive either. That said, maybe someone on here can give some good advice.

Last Tango · 31 May 2015, 05:57

Had a V8 jet boat for a couple of years. Just wouldn'd go in a straight line till it was at semi-displacement speed. Was also guilty of sucking pebbles of the bottom in shallow water and firing them through the jet, kept damaging the impeller.

biffer · 31 May 2015, 07:37

You lose your steering when you lower your revs, if you try to drive it like a normal boat you'll be in trouble, take it somewhere quite, pull the revs up to about 2k, move the bucket till you're stationary, put your steering over to full lock then move your bucket control from neutral to forward and then reverse, it will take some practice but you should get the boat doing circles in its own space.
When working at one rib builders we were experimenting with skegs to get the jet boats going in straight lines better at speed, politics at the company didn't let us finish our testing

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Razorbill RIBs · 31 May 2015, 07:59

What jet (manufacturer ) are you running?

skovmand · 31 May 2015, 08:19

I have the setup of a VW engine and a castoldi 05 jet

Last Tango · 31 May 2015, 10:56

Quote:

Originally Posted by biffer

You lose your steering when you lower your revs, if you try to drive it like a normal boat you'll be in trouble, take it somewhere quite, pull the revs up to about 2k, move the bucket till you're stationary, put your steering over to full lock then move your bucket control from neutral to forward and then reverse, it will take some practice but you should get the boat doing circles in its own space.

Problem I found was trying to stop it doing circles in it's own space. Didn't really have a "neutral" so even idling it tended to try to spin. To encourage it all that was required was to give it a little bit of throttle in "neutral" and the combination of the bucket and nozzle position pushed the stern sideways without any forward or reverse movement, but it was a pain, if you were trying just to sit still the engine had to be stopped. (PP Jet)

biffer · 31 May 2015, 11:10

They are buggers to drive for sure

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Daniel · 31 May 2015, 11:23

I've taught myself to drive a jet rib recently. Some minor collisions were an important part of that process, so lucky it wasn't a jet hard boat is all I can say.

Most but not all have back-to-front steering in reverse. You've probably worked that out. I still have to think it through and remember wheel clockwise boat turns clockwise in F or R and visa-versa.

Like others have said. More RPM at all times (minium 1800-2000) and control thrust on bucket. Never close the throttle to tick over.

And yes it will always wonder. Once you're tied up switch it off - simples.

What's interesting is I parked my outboard RIB badly yesterday as the pivot points are so wildly different in the jet rib...

willk · 31 May 2015, 12:10

One of the recent big Redbay jetboats was fitted with hull mounted fins from new. I'd have guessed that they were intended to improve linear tracking?

skovmand · 31 May 2015, 12:29

Thats not My problem because in a castoldi jet is There a neutral position so that the jet is standing still .

My problem is when i sail with low speed it wont go in a straight line

biffer · 31 May 2015, 13:27

Pull the revs up, to stop it going faster pull the reverse bucket down slightly to combat the higher revs, remember you're driving a water pump low revs, low pressure, no steering

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skovmand · 31 May 2015, 19:25

Thanks for the answers i Will try that the next time i have it in the water

Razorbill RIBs · 31 May 2015, 19:55

As has been said, there's no getting away from the fact they can be a pain to keep in a straight line at low speed / off power, but seeing as it's a Castoldi it uses steering flaps rather than a directional nozzle....it's also worth checking for movement / wear in the steering flaps on the jet... Not sure if the 05 set up is as per the 06 (likely very similar) but we found that the brass gears which mesh to give steering wear with time and allow the flaps to be sloppy, results in worse steering and less control.... Replaced ours and was very surprised at the improvement....

skovmand · 31 May 2015, 20:33

Thanks i Will take a look at that part to

Rokraider · 05 June 2015, 12:46

I have a Pacific 22 that is fitted with a Hamilton HJ273 jetdrive. As others have pointed out, for manouvering at low speeds, I keep the revs at around 1200 RPM and then put the bucket down approximately half way, which effectively diverts half the thrust downwards and check my speed by raising or lowering the bucket. I can literally inch up very gently to an obstacle with virtually no speed, yet the engine is revving a little.

Keeping it in a straight line is quite an art and requires practice. It is easily influenced by waves and windage. I have passive hydraulics on the steering, which doesn't help either. There is a certain amount of slack in the system and the wheel never points in the same direction twice, so you can't judge where the nozzle is pointing. I am thinking of converting it to cable, so the system is more positive and the wheel will tell me where the jet is pointing.
Have been considering a couple of skegs to improve the straight line accuracy.
I have a couple of large Bennets hydraulic trim tabs that help a bit, by getting it on the plane quicker which helps with the straight line.

They are tricky, but rewarding when you get the hang of it.

skovmand · 10 August 2015, 20:29

Thanks rokaider
Now i have been out on the water a couple of times .
And you advice works realy nice.