Greg Lukin

I got one... It's not a slalom boat. I could go on a massive rant about how we've been stuffed around /ripped off by these guys but I'll hold off until I exhaust every avenue. And yes these are the same guys coming over to the states from Aust to set up and build these things. Terribly old school hull - great footing with an outboard. They do make a smaller version called a probe - outboard wake is almost non existent - inboard is not too bad.

@Dacon62‌ - come back for a visit I got a nice little course you can have tow through. We will get there - It will take some time though - just getting into summer so its frustrating. I'm still recovering from a broken foot - the ski gods are against me !! lol cheers

I can't upload the video from my phone so I'll try and put it on youtube later. But it's very clear that adjusting the cav plate made no improvement - probably worse for cavitation. Hole shot is fine up till 3000 rpm and then it jumps to 5500 rpm before kicking back in. The cav plate did have an effect - it gave us an extra 200 rpm at WOT - now 5800 (too high prop was 13x14) The cav plate help the bot turn at "higher" speeds - over 32mph seemed to turn "ok" but still not great. Under that speed was terrible. When we loaded one person in the rear the boat turned well. So now its back to the factory for them to sort - my hunch is that they wont take the time to test and fix the handling issue which is frustrating for me. What else could make the boat perform better? Moving the engine back a few inches to get the weight off the nose? Massive job and no guarantee it will work. It might make the wash worse as well? So options are 1. Leave it and put up with the bad turning - drop the cav plate slightly more to improve wash a little. 2. add weight (lead) to the rear of the boat - not a great fix but might be the easiest answer - but could increase wash. 3. Try and move the engine to the rear of the boat - big job??? Then we have the cavitation issue - Any prop guru's around? I don't really want to drop down in size for diameter but I think with the prop shaft angle we have no choice. Next to test is a ACME 2209, 12.50, 15.5, 0.150 cup, 4 blade - not sure a 450 HP engine should have such a small diameter? but we need to gap under the hull to increase in order to stop the cavitation (well at least thats what I think is causing it) This is really frustrating... oh - and yesterday we couldn't engage neutral - it stayed in gear - pretty sure its just the cable throttle needing adjustment but still on top of everything else it got me cranky. So now it stays in the shed till next week when it goes back to the dealer to sort out - Things to repair by them. Handling issue install Zero off fix bimini - flapping around move mirror to windscreen mount (not bimini) hot water shower install fresh air exhaust install throttle cable adjustment engine cover insulation and a few other minor things rant over....

Ended up working on the cav plate last night - it's now sitting only slightly lower than the hull. Testing this afternoon - fingers crossed it helps.

Good idea Greg Hind - I'll video next time I'm out - didn't really watch the rpm for hole shot test. What actually happens is that in the first second after nailing it - it's fine - it grabs and goes - then a second or so later (whilst the boat is still getting on the plane) it cavitates for less than a second and then it stops and takes off - for the very brief moment it does cavitate id say the revs get up to approx 4500. Hope that explains - in the video I will take you will hear the moment it all happens. We are going to adjust the cav plate tomorrow after work and try and get out for a quick test late. Hoping that will stop the cavitation but it could also make it worse...

Hi again, Interesting prop testing yesterday. Tested a ACME 13x14 3 blade - WOT rpm was 5600 - good. However 1 sec of ventilation/cavitation occurred only when we flattened the throttle for hole shot test - which was the same as the previous prop (13.25x14 4 blade) - but not as bad. Remember the gap between the bottom of the hull and the prop was only about 6mm hence why we went down in diameter - which worked better but perfect. HOWEVER - when we had someone sitting at the rear of the boat there was no ventilation/cavitation?? AND the boat turned beautifully like a boat should - obviously lifting the nose of the boat helped - so that means the cav plate must be the cause of the poor turning. So now my thoughts are that I hold onto this prop and adjust the Cav plate and see how it performs then. The only other prop is a 4 blade 12.5x15 - not sure I really want to drop that low in diameter but worth a test I guess. Wayne - the rudder shaft from my limited knowledge looks to go through a nylon bush with three bolts holding it down to the cav plate - I "should" be able to simply loosen the rudder safety collar and loosen the bolts and then move the cav plate. I think your right that the cav plate has a shim creating the angle - I want to remove the shim and take it back to flat but I just don't want to stuff it up - the guys are back next week so I'll be patient for now and get them to do it and then I'll just ask them how to do it in the future so I can play around with different angles etc. There is light at the end of the tunnel!! thanks for your help so far everyone.

Photos as promised

The plate is attached with three hex bolts through the running surface of the hull - that small part of the hull has been molded to fit the plate flush to the running surface - I'll get pics which will make more sense.

Greg - thanks for that. Got the prop size wrong. We are going to trial a 13x14, 0.135 cup not a 12 diameter. The cav plate is "not" adjustable. I'm not sure how they have set it but I presume they use a packer of some sort to create the desired angle (I'll get some photo's soon)- to do that we need to undo the bolts and change the angle and then bolt it back up. Also the rudder goes through the cav plate so that bush might need adjusting if we change the angle. It's not a 5 min job and since it's new I'm not keen on adjusting it myself until after I talk to the guys in the factory about how to do it without breaking things - problem is they have closed the factory for another couple of weeks so I need to be patient and wait (although I have been close to pulling it off and seeing if I can adjust it - it should be easy) We have gone the 450 - why? We just thought get the latest and greatest as we tend to keep our boats for a while. We certainly foot a fair bit but my main aim over the next summer is slalom course work - yes it will have zero off as soon as it goes back to the factory - it was an option we ticked but they didn't get "time" to install it before they closed the factory (quite annoying). I'm confident the boat will be great once we iron out the issues. Cav plate adjustment, prop selection and installing zero off should make a lot of difference. Cheers

Aussie summer kicking in here - can't wait -

Wayne - that is exactly what my thinking was - thanks for that - I'll get it set to roughly 3/16" and see what that does to the handling of the boat. Top speed isn't a problem - especially once we get the right prop - with the PCM 450 engine there is plenty enough power down low and at top end. We tried a 13.25x14 four blade and it sucked air causing cavitation. Now we are going for a 12x14.25 with a bigger cup size - 3 blade - (sorry don't have the Acme codes with me) hoping that will give us a max rev of 5500 and still plenty of hole shot.

Hi all. The steering is fine. It's just that the nose of the boat digs in when turning sharp. We are taking it back to see what they can do. It's a custom protege. The boat they use in the barefoot worlds but ours is an inboard. PCM 450. Should have gone with the 409 as we are stuffing around with props and no one knows what to expect from it as not many are in boats over here in oz

Hi all. Our new boat has a cav plate but is angled down a fair bit~ about an inch below the hull. They reckon it makes the wake better for skiing which I understand but we ski in a narrow lake and need to turn sharp. The problem is that when we turn the bow of the boat pushes down and makes turning very difficult due to the amount if water it is pushing... Question is. If we lift the cav plate to half the angle will that make the boat turn easier? Any thoughts?

Go Joel!!

Can you use Rec mode for free skiing ie: not in the course? Or do you need to use trick mode?

@mmosley889 I've been trying to get onto you about purchasing an OB4 system?? can you pm me or reply to emails sent - thanks - I know you must be busy but it's warming up over here in OZ and I'm keen to test this foot of mine on a ski.

Hi guys Looking at buying a HO A3 soon - I found a couple of good looking second hand 2013's - is there much difference between them? I've read a bit about the base but don't really know if it's worth the extra $$ I'm running 36mph - aim of having a few attempts at 28 off - so nothing spectacular. Thanks

Hi guys Currently looking at getting into 36mph and my goal next summer here in Australia is to get into the 14 metre line - training twice a week. I'm 95Kg's or about 210lbs (looking at getting that down a bit) 6 foot 4 I currently ski on a 69 but looking at dropping down to a 68? Also found a Radar Vapour Lithium 68 for sale for $1000 on ski it again and thought it would suit me?? I'll be adding the OB4 boot system for sure - after my broken foot recently. thanks all