Setup

The Docta · 25-09-2006, 01:59 PM

Hi Everone

Recently upgraded from a Ring 18 to a Ring 21 (divertoms old rig). She's equiped with a 250 3.4l merc coscast turning a bravo prop on a gill bracket, with trim tabs, twin batteries and fuel tanks at rear but no balast tank.

Problem is that it chine walks (i think this is right term - i.e. boat leans when given throttle) quite badly and feels v unstable - the chine is not so bad as it can be countered with trim tabs and by trimming out.

However, when we've tried to trim her right out for more speed, she get a wobble on (snakes uncontrollably) and feels like she's gonna go over - scared the shite out of me really!. No choice at this point but to throttle right back when this happens.

She seems to be right on the edge all the time and is really fiddly to get right.

Our old rig was nothing like this. It was really stable and although it chined a little whilst trimmed right in, it could be trimmed right out no probs to such an extent it would put up a 10ft rooster and still feel as stable as could be!

When we tried the new rig for the first time she had several v large sandbags in the bow - now removed these as they were not strapped down and concerned me - should this improve things.

With all the experience, what do you guys think? Is it set up wrong?? - Engine too low? Try a different prop? Need ballast?

Or should we just get more seat time and get familiar the present set up-

On the plus side managed 60 mph out of her without too much difficulty running at just over 6000rpm

Bad Boy 717 · 25-09-2006, 02:47 PM

Bow tank sounds like the solution to me . . . . . now lets sit back and see what the other boatmadders have to say

Cyco · 25-09-2006, 03:24 PM

Got a freind with the same set up, his doesn't chime walk but he does have a bow tank.
His boat steers to the left by it's own accord when flat out, almost like a hook but a bit slower.

Those engines aren't really god for much apart from drinking fuel.

Jon Fuller · 25-09-2006, 03:36 PM

ding dong

sinkunit0 · 25-09-2006, 04:15 PM

is it a 25" shaft

BluFin · 25-09-2006, 04:18 PM

Engine offset ?

Dan · 25-09-2006, 04:40 PM

Bow tank. I went out a few times when Tom had it and he used to put sand bags up the front which seemed to work

The Docta · 25-09-2006, 06:02 PM

Cheers everyone

I appreciate that the motor drinks fuel like a glaswegian getting stuck into tennants superstrength

but is very low hours and is absolutly spotless. From what I understand though, it should be a reliable workhorse.

So until I get a bow tank sorted should I re-balast it with sand?

By offset, are we talking offset to the left or right? I think its dead centre at the moment should it be offset and if so left or right (and is this determined by prop rotation?)

Was it worse befor the ballast then Dan??

Aso with the trim tabs, only ever used them on a larger cruiser (Falcon 27). Should we start with then right down, and work up or visa versa.

Think is an XL shaft

Thanks again for all the input - Al

sinkunit0 · 25-09-2006, 06:15 PM

Think is an XL shaft

i think thats the problem

The Docta · 25-09-2006, 06:21 PM

any suggestions for supplyer / fabricator of bow tank

So if it is an xl shaft can it not just be jacked up to compensate??

Dan · 25-09-2006, 06:35 PM

Quote:

Originally posted by The Docta
Cheers everyone

Was it worse befor the ballast then Dan??

Aso with the trim tabs, only ever used them on a larger cruiser (Falcon 27). Should we start with then right down, and work up or visa versa.

Think is an XL shaft

Thanks again for all the input - Al

Bit of a story really, I think I'm right in saying that Tom only put them in after the first time he tried to lauch it. He told me it sat so heavy arse end when it went it that he was worried it might stay on top of the water while lauching, hence I dont think he ever run it with out the ballast. As for the trim tabs, I dont think Tom really got round to using them in any detail, as me me I sart all the way down while going through the 6knots area to keep the nose down so I can see!!
It is a nice boat you got Docta, if you are going to tow it any great length you may want to look for a twin trailer apart from that its mint.

The Docta · 25-09-2006, 06:53 PM

Cheers Dan and thanks for the advice mate

Shes clean as a whilstle and a credit to Tom! I'm sure Tom has mentioned, I share her with a mate so we can split the running costs. Need to as wel with that motor We did £60 in 2 hours on our maiden voyage

Only towing short distances so trailor should be ok. Just very concerned about set up.

Im relatively experienced but still got scared when it got a wobble on. Converted it back to foot thottle so should at least have a little more control next time - Tom's a brave man for driving it via hand throttle.

PS was looking at the pics and hotshot and she looks sweet!

Burty · 25-09-2006, 07:33 PM

dude the leaning is having it trimmed in to far with that prop / setup just trim it out more.
the chine walking (wobble as you call it) could be down to the steering / play in midsection what steering are you running?

Cyco · 25-09-2006, 08:07 PM

It could be down to poor set up of the boat.
Where are the batterys located?
Also where is the trim pump and the trim tab pump?

Maybe take a couple of photos of the rear of the boat?

Including the fuel tank position.

Taz · 25-09-2006, 08:26 PM

My 275 was xl shaft tried jacking engine up making it worse, Moving battery and pump made alot of difference, I even tried fitting a nose cone to the gearbox but didnt make no difference.. The boat was great up to around 60 then it was a waste of time trying go faster.

Taz · 25-09-2006, 08:39 PM

Taz · 25-09-2006, 08:39 PM

Taz · 25-09-2006, 08:41 PM

This engine dwarfed the p20 was so clean but way to big and heavy!!

The Docta · 26-09-2006, 08:27 AM

Only pics ive got of setup were taken by previous owner - attached

The Docta · 26-09-2006, 08:28 AM

Stern