All good advice. Definitely do the alum wedge to straighten out the rudder on the transom and get it vertical.

Make sure the tabs are mounted about 1/16" above the bottom of the hull so that they aren't dragging in the water when set to level. Some monos will run ok without tabs, but 95% of them require the tabs for overall best performance. Generally I've found having 4 tabs separated (inners and outers) has been best on monos.

Hard to say how deep your drive is set, but I would start with the centerline of the propshaft at 1/2" above the keel and have a good 1/8" up/down adjustment available from that point. Keep the drive level with the keel (or the table with boat sitting on flat table). Adjusting the height will change the ride attitude and also very importantly help unload/load the prop. So sometimes you can get away with a bigger/higher pitch prop by raising the drive... often times at the expense of some propwalk though!!! Test test test.

The starboard (right) side fin should be remounted on the transom to get the bracket as low as possible without being in the water. Have the fin com e down 90deg with the bottom of the boat and right on the chine line. Looks like you have it right as is, just not deep enough. Slot the fin or bracket to give you a little bit of up/down adjustment for tuning. Can do the same with the port side fin if you intend on doing a lot of left turns. In theory you want the fins as deep as possible without touching the water (setup table) when the boat is straight. Although on some hulls it can be necessary to go even deeper.

Last thing...the pipe... looks like it's not adjustable...based on my own experience, most of those wrap-to-center pipes end up being too long to actually tune correctly for our engines, especially when modified, so this in its own maybe one of the causes of the engine not revving up to its max. You could probably accomplish the same basic setup using a 100deg header on an adjustable pipe, or even a 90deg and keeping the pipe inside the hull completely with just stinger exiting the transom. Just some food for thought. Start with the other stuff first for sure though!

Keep us posted.

Hi Darren

You are welcome to any advice I can offer. As with all advice I always take the view that it’s best to listen then bin what is not relavent.

My Lynx was bought from PBM. I opted for “Deal 1” which included practically all hardware except the radio. I then built it from the hull up.

I like the fact that you built your radio box out of ply, it looks neat and when building your own box you can get it exactly the right size.

In my opinion for the money you’ve spent you have done well.

In respect of the extra photos, I think your turn fins definitely need angling down because with the brackets quite a way up from the hull bottom, I’d suggest that you’ve only got about 25% of the blade area in contact with the water.

And yes the rudder support bracket I believe definitely needs to be re-fitted so that it is close to horizontal. It will among other things make your push rod linkage operate more smoothly (I suspect it probably binds a little at the connection to the rudder arm at present). An aluminium packing wedge would be ideal. You could I think also use some strong quality hardwood as long as it is well sealed with resin.

In respect of the 67/13 prop: Its pitch is 1.3 x diameter (67) = 87.1mm. Your prop has much less pitch than all of those I’ve tried. I can understand why it revs high with not enough thrust.

My 67/17 three blade has 1.7 x 67 =113.9mm pitch which my stock Zenoah pulls comfortably. And it runs much faster than on a 2 blade Octura X470 which though 70mm diameter has 1.4x70mm pitch = 98mm pitch.

I don’t know enough about your power plant to be able to advise you on a particular prop. Others have a lot more knowledge on props than I. Propeller theory is a very complex topic.

However just a couple of points I would offer:

I’d avoid the cheap props because in my opinion they are false economy. I started off with two cheap alloy props. When I bought a bronze equivalent at twice the price the alloy ones have not been used since.

Secondly which ever prop you use, be sure to have them very sharp and accurately balanced. These two factors alone I have discovered make a Huge amount of difference to performance and reliability.

Cheers
Craig

Hi Marc thanks for the advice its all noted,so the WTC pipes are quite restrictive then?if i had have known i would have got the other type so i could adjust the header pipe length.As im just starting out in the hobby i,ve loads to learn but willing to listen to experienced boaters who are full of useful information that helps no end.I shall look over these few issues i have with my boat soon as children allow then report back with maybe a video so everyone can see the results.Again thanks for all advice given.DARREN

I think it would be worth noting,,,Give your prop a good work over..Make sure it's balanced and is nice and sharp on the leading edge. This will also help with torq roll and prop walk..Only do this if you have a good prop balancer. I think Marc (admin) may sale them...Welcome abroad...