ozzie

i have got 41' jag cat hull ( same as falcon ) . i have set up everything & taken boat for run,have modded 26cc omen engine . i am pretty happy boat is runnin very close to 80 km (50mph),but pullin right at full noise & to me seems a bit nose heavy. would love to know anybodys opinions & comments on balance & set up
oz

ozzie

i was told when i bought hull to mount motor as far forward as possible as i can get it . seems nose heavy, would like to c nose a bit more in the air , plus as soon as u back off nose drops & its like u hit the brakes . have heard about balance points n would love to know what sort of measurements they r .

gtdad

How modded is your zen? What prop are you running? What is the strut height? What is your rudder angle? Any pics? The more info, the easier it will be to help.....

Paul M

As mentioned, pics would really help. Under 50 mph is really slow for that hull.

Take a 1/4 in wooden dowl and put it under the hull on a flat table.

Put a piece of masking tape on the hull so you can mark where the hull balances.

Roll the dowl back and forth until the hull teeters back and forth balanced on the rod and mark this point where the dowl is on the hull.

Measure the distance from the transom to your mark. Divide this measurement by 41 (length of the hull). You want it to be about .34.

Example.

15 inches transom to your mark divided by 41 inches = .366 > Boat too bow heavy (more than likely your problem)

13 inches "" """ """" """"" = .317 > Boat too light in the bow ( Blow overs will be an issue)


14 inches """""""""""""""""""""""""""""""""""""""""""""""" = .341 > Good balance point


I am betting you have your engine too far forward for the amount of power your engine is making.

Hope it helps.

Ron Olson

My Feedback: (1)

OK, you got some bad advice. I bought mine used but never saw water. The previous owner also had the engine mounted way too far forward so I had to move it back about 3-3/4".
A quick test it to float the boat to see how it sits in the water.

ozzie

i will try n get photos on here today , i am a lot betta with with boats then i am with computers. as 4 props i have only tried prathers 270 & 275 , ihave also tried octura 1667 which seems to have a fair bit of lift & pushes nose down , i called daniel from omen race engines (where i got my motor), he has suggested a 6717x3 blades & a 7016x2 blade props, as 4 skeg i am as high as i can go & kicked back at the bottom as far as i can get it . hull is still in gelcoat so changing skegs & stuffing tubes is no major issue, as i will not bother to paint the boat until set up spot on
oz

ozzie

hope these photos come out airight

Paul M

I don't see anything bad wrong with your set up. I tried a 1667 with mine and it glued the boat to the water at about 50 as well even with the strut up and negative like you have yours.

I think your strut is too high. I see that you already tried lots of negative to get the nose up.

You need a 2716/2 15 degree. Put the strut down at neutral. You may even need a tad of negative to keep it on the water. If your engine is worth anything you should be at least 60 mph.

What's your cg?

ozzie

im guessing when u say cg , your talkin balance, i measured hull at 14 1/2'' no fuel, 15'' full of fuel
oz

MrMikeG

1st, no 2 hulls are the same so to say "put your motor as far forward as possible" is the worse advice ever! Measure your CG and compare it to others. 1 ounce more resin in the nose will change your CG by 1" or more!
Daniel (Omen) builds a good motor, they like to rev, it will all be about props to get you faster, your selection of props is not the best for cats, fine if 80 kph is all you want but if your looking for a SAW prop you need to keep buying props!

Tahoe1970

My 2cents worth is.......Your flex cable is a big problem , You need at least a 1/4 gap between the strut and your drive dog when using a collet drive. When the prop is under load it's binding with no gap. Take that 1667 off ...those props in stock form are more suited for hydros that require lift. Between the shaft and the lift from the 1667 your boat isn't gunna go very fast.
I would put a 2716/20* prop on that boat and hold on to your shorts cuz it's gunna get up and fly.

Wally

P.S from what I see....the motor is fine where it is correct the other issues first

Ron Olson

My Feedback: (1)

Wally already got you on one thing so if I may, a couple of other things. Get rid of that streamlined prop nut unless you like buying lots of props as those things are notorious for falling off when you don't want them to. If you insist on keeping it, slide a sliver of silicone tubing between it and the prop nut.
Get that rudder parallel to the transom as that will push the nose down.

scooter666

Oz...
Heres acouple of pics of my set up on the jag cat, pretty much the same but i cut off the rear tube bit on the strut and im running a exhaust bracket. I also found that vinyls are easier to replace than paint.
Cheers Scoot

benckie

Hi oz

ive been looking around alot of these falcon cats, and most with full mod motors have the cg around 34 to 35% as far foward as you can get the motor, so i would take that as good advice for that cat, i would listen to wally and go for a abc 2716/ 2 20*.

im not the most cluded up rc boater, but like on your mono, you might start snapping shafts and loosing props if you dont have more gap between the strut and drive dog, on my cat i have 1/4 inch or 6 mm gap tolet the flexi shaft to shrink under load.

im sure with a new prop and start over again on the strut adjsutment im sure you will be going alot faster, from what ive read about these cats, with full mod zens and quickdraws in them they are fast and a little flighty butmake for good fun

ozzie

your right Mike ,Daniel builds awesome motor

ozzie

thanks Wally i have never heard that before , should make huge difference , cant wait to try that out .
oz

ozzie

thanks Ron , i use a thread sealant on nut , it is actual a hydraulic thread sealant not a thread lock , as thread lock is miles to hard to undo , i use it on every nut & bolt on motor & hull that is not nylock or spring washer , works a treat. loctite 577 , good stuff. rudder angle appears far worse in photos as rudder is bolted to transom (should be parrell)
oz

ozzie

looks great scoot .
oz

martno1fan

Wally hit the nail on the head you have no gap behind the strut,you need 1/4" between the strut bushing and the drive dog .Your cables shrinking under load as they all do causing your dog to bind on the strut as you have no gap which is slowing you down big time,if you keep running like that it will lock up and snap the flex or worse.Make sure you have a gap and it will run a lot better ,also as said change the prop to one with less lift and as Ron says ditch the bullet prop nut for a zuber nut or at least a nyloc nut.
Mart

ozzie

thanks Shane , as i i said to Wally i have not heard about this gap between dog & skeg , cant wait to try as i have always tried to have no gap.took boat 4 run today , came home pretty happy (only 3rd time out).onlychangedprops, with no changesto set up
started with prathers 270 ran 53.4ml (89k) at 18,600rpm full fuel (500mls)
prathers275 ran 50.3ml(84k) at17500rpm
octura1667 ran 51ml (85k) at 18,800rpm
prathers 270 ran 55.2 (92k) at19440rpm with 1/4 tank of fuel
on last run nose of boat was tryin to get into the air a lot better.lookin forward to try all these ideas u guys a suggesting to me , i realy appreciate everybodies help & opion.
one thing i forgot to mention is that the prathers 270 is the only prop that has binprofessionaly sharpened the rest i have done myself (may explain y they r so slow)
oz

eengler

Drop the strut flat with the sponsons and use a 2716x2 20 rake like wally said. This was my cat before doing 60mph on a stock engine with a rounde, cupped 2716 20 rake. It will run really nice with the 2716x2 20 rake. http://www.youtube.com/watch?v=ibNTAUfGhC0

ozzie

hey Mart , i agree with u Wally, Ron & Shane as skeg has lost some of its positive on runs ,this explains a lot to me. thanks
oz

ozzie

Gday eengler, i have seen your video on u tube many times before , with much jealousy ,lol,but with so much good advise as i am recieving from blokes such as yourself i cant wait to as fast
cheers oz

benckie

oz, i tyred to explain the gap between the drive dog and the stringer or strut befor but im crap with words, no gap with a strut will pull the strut into the transom and slow you own and it will eventualy break and you will loose your prop.

on a stinger drive there is no movment so it would slow your motor right down most likly break the cable at the weld and you will loose your prop and shaft out the back of the boat.

my first gas boat was a square drive that used thrust washers this is the only set up you dont need any gap, but runnign welded shafts you need a good gap like 1/4 inch withc is around 6.35 mm in our terms.

55 mph is good, very good for a pantra 270 witch is more of a mono prop, try tthe prop wally recomended and it will be quicker again and run like a cat.

ive heard the omen motors are a good hydro motor and they like to rev out, ask Daniel whats the max revs for the motor and keep it just under that, as 20 k might be a bit much, but i would aks him or tony gritter to check

ozzie

thanks Shane thats the 270 i got off u . was talkin to Daniel(omen) he reckons about 17,800 is a good range , but i am very happy from what i have seen today,great motor (omen) & great hull 4 the price. from what advise all u blokes r givin me if i get to 60mph i will b very happy man
oz