What could be wrong here then?

[Andy JC]

Floater:

Thanks for the pic, my keel looks similar to the one in your picture.

Did you find that the engine cavitated/ventalated more than it should?
Did your floor move around quite a bit when planning?
Did tou try playing around with toggles, ie undoing some/one?
After it was repaired how did the boat handle?

Cheers for any advice...

[J S]

Regarding your picture i have a 2005 model 340 acti-v zodiac. Mine blows up in exactly the same way with the keel slightly off centre. The thing i found that made it cavitate was having the trim tabs on (i now never fit them to the boat). I ordered them with the boat thinking it would help and it did help get it up on plane faster but it seemed to hold water back and create a bulge in the floor towards the back of the boat and then release it all at once every few seconds causing it to cavitate. I also found if you have too much weight too far forward it cavitates. When i first got the boat i spent a day playing aroung with the trim i found the best setup for everything was to have the trim bar out two holes from the transom that was where it cavitated the least and best acceleration and top speed.
Mine now rarely cavitates except in very tight turns

Just out of curiosity what do other people get top speed wise with a 15hp on I have a Honda 2005 model. I have yet to get an accurate top speed reading.

Ian: I had the same problem with the weed making the engine cavitate. My engine stalled at low speed ( Very rare for a Honda ) so i started it back up no problem and started to accelerate and it just kept cavitating so i lifted up the leg and i found two feet of seaweed attatched removed it and it was fine.

Picture attatched: i have found no problems with the boats handling because of the off centre keel e.g tracking off to one side.

James

[Mollers]

Originally Posted by ian parkes

surely if the keep wasn't fitted strait then thats the problem . It would be creating a wierd and inconsistant flow past the prop .
What you want is nice little Honda Air floor none of that hassle with floor boards and keels , as it happens I just

My sis wants a Sib.

[floater]

I Messed with every thing and anything to try and fix but apart from doel fins nothing seamed to work

i returned back to MGA i rochdale who sent it to an approved repairer in cornwall, it was better when i got it back but as i said i tried my mates bombard 420 and my other mates Zodiac pro, another mates medline 1 and then my brother in law bought a pro 9 as well so sold on ebay and bought avon 400 week later

also be very very care full with the handles as mine rubbed through the fabric
! and the seam in the bow split and the air deck rubbed through on the self bailer

[J S]

sounds like you got one of the bad boats

[floater]

i tried to track it one up on a hand held gps but i was all over the place !
the best i got was 1 up no seats half tank of fuel with the tide touched 30mph according to my mate who was along side

then hit big bow wave and went air born S**t my self

i know my boat looks in a mess in some of the pics but it was cleaned honest

and i do miss it every now and then do wonder where it went, sold to some guy in portsmouth for 1500 who sold it 2 months later for 1900 to some body over nottingham way ? and used my origional advert !

ebays great

Andy

[Andy JC]

Thanks for that floater, know where you're comming from regarding a bigger boat but I've been there (experimented with 2 others this year already) and have found that the size/weight combo of the cadet is just perfect for my beach sinario, provided I can get it to run right.

Good to hear from J S that hopefully the 'off-centre keel' shouldn't make too much difference. Might try undoing one or two of the toggles, have some experimenting to do this weekend - all part of the fun

[ian parkes]

I don't like the look of that , what if the boat flexes into a big wave , surely the keel could move ?

[floater]

dont get me wrong i loved that boat and had from nearly new
warrnty is good and dealer service was excellent
we had some good days out caught 68 mackrel in a hour off that there dinghy


heres a better picture doing what it did best

Andy

[floater]

Originally Posted by ian parkes

I don't like the look of that , what if the boat flexes into a big wave , surely the keel could move ?

the boat tends to either slap the wave or bend with it

remember inflatable air deck to 11psi its very ridgid but still flexises

please excusses spelling getting late

Andy

[ian parkes]

don't worry i couldn't spell earlier .

Does seem to me that Honda have the inflatable v floor sorted . It too flexes and gets uncomfortable in a chop , but I guess all sibs do . However you just blow it up and go no friggin about with toggles and keel trips etc its just one piece .

[floater]

i think that that is the problem

the earlier <2002 and zodiac310 and below have a seperate inflatable keel that is inflated through a hole in the air deck, whilst the later and 340 models the keel is connected via a pipe to the underneath on the main floor and takes its pressure from the main air deck

so its not possible to inflate the air deck fist then the floor as both go up at the same time

i did get mine straight once or twice by inflating air deck with boat on its side and sticking my knee in to it ! whilst misses blew it up (huumm)

not best choice of words

[Andy JC]

30 Mph in a cadet!!!

must've felt rapid...fair play though

Certainly does sound like you had a dodgey one, glad you had some good times in it, hopefully so will I in mine oh and doesn't mackrel tatste great on the bbq (I'm sure it's the hunter/gatherer thing)

[floater]

the best fish to BBQ

pics attached from last weekend

some where between Phillwi and shell island just off Ccricith

Andy

[Andy JC]

Ok, just checked the dimesions of the propeller and it's a 9-11. Presume this means it's a 9" prop with a 11" pitch.

I've got a 17 years older(1988) version of the same engine which I've been using on a 3m Avon for years without any ventilation problems at all. This one has 9 1/2-10 stamped on it which I assume means it's slightly bigger in diameter but with a shorter pitch?

Could this mean that the newer engine I'm getting problems with is geared slightly too low and hence slipping when accelerating or would the different proportions in diameter and pitch cancel one another out (ie smaller prop with longer pitch is the same as larger prop with shorter pitch) ?

The prop from the old one fits ok so will give it a go next time I'm on the water but I just wondered what people's thoughts were on this...

I know there's loads of posts regarding pitch etc but couldn't find anything specific to my problem.

Thanks for any comments

[The_Heretic]

Ok, hi all just registered

Im a total newbie to all this, but having use my own Cadet fastroller acti-v 340 a couple of times now, I have noticed something similar.
I drive it on an old (20rys) Evinrude 10hp 2-stroke, and occasionally itll "spin up". I thought this to be the prop leaving the water through ?
Ive used it only on Loch Lomond, which can get a bit wavey in the perpetual wind you get there, and I had assumed it was this which was causing apparent "slipping" of the engine.

Last weekend I was out, and the water was dead calm, I was able to whip about carving tight turns, without any hint of this phenomena.

On another note, I can always let rip with the throttle from a standing start and whilst the bow rises up like an angry elephant, theres no slippage. My point is Ive only noticed it when Im haring along and there is a swell (say, 2feet) in the water.

Dont suppose this actually helps , but it is possibly another line of thought to consider. ie see how it runs on a nice calm day before doing any drastic mods

On a completely different note, how do you find a 15hp runs on your boat ? I thought 10hp was the max allowed - Im thinking of a new engine
Ill maybe open a new thread for that question.

Next time Im out, Ill be sure to experiment and see when and where I can reproduce the effect.
Thankfully my own keel runs pretty straight down the line (first thing I checked when I got it).

rgds,
Heretic.

[J S]

10hp is the max recommended but the max allowed is 15hp. I find mine runs very well with a 15hp the boat can cope with it. I did a speed run along side another boat this weekend and got 26knts gps with very low fuel 1 person and minimal kit onboard That was early one morning with flat water it was running perfectly you can feel the wind lifting the boat up of the water. I find if you have a few people in the boat the extra hp helps. I also did a bit of kneeboarding off my boat for the first time i thought it towed very well. Two people in the boat driver and spotter and relativly light person on the board.

James