5.2m Kevlacat Re-Powering

[rat_catcher]

Each side has 110 litres so 220 litres for the boat and there separate systems one tank feeds one motor.

Each side is using between 10 and 11 litres per hour at cruise of between 22-24 knots so 22 per hour for the boat.

Giving me a range of about 200nm or360 km's before the need to carry extra.

These figures are bassed over the last 60 hours of use

Thanks Ian. Very interesting figures as they have more range than I thought they would. Also 22-24knots is about perfect for ocean cruising.

[Dean1]

Daniel im thinking the 5.2 ur looking at is the one at harvey bay? Nice boat, I did the figures and it weighs up to be quiet a costly outfit. $8100 each for the f 60"s is a good price, about the best I could get them for. 90's are way over the top for a 5.2, jodie told me that they were max power for them but its not the case., 60 2 strokes or fours are fine.

[Smithy]

I know a guy that went from twin 50 4 stroke Mercs to 90 two stroke Yammies on a 5.2 KC on the say so of Fred and Michelle Temminck just before they sold KC. The 50s were way underperforming but very cheap to troll with as you could imagine. The boat was called Sealord and was on the southern end of the Gold Coast. It only lasted a week or so on the secondhand market and was bought local. It should be still around. Darren loved it with the 90s. He was doing Tweed Bar and stuff with it a fair bit back then so the 50s were too scary for him in the performance stakes.

[finding_time]

I wonder how he goes with his insurance as the compliance plate on mine states ..max hp 70

Ian

[lenm5]

Yam F60 High thrusts would be nice but are they worth spending the extra$$ over the standard ones??
I don't have a KC so wouldn't know - but I have a smaller fibreglass cat (4.6m) which runs twin Yamaha 50 4strokes.
With 2 full tanks of fuel (80L each side) it planes on a single motor.

[finding_time]

Lenm

Apparently you do need the extra umph!!! have talked to 2 people who tried 50's and they didn't work real well . My KC wont plan on just 1 motor it comes close but just doesn't quite get there. The KC 5.2 is a fair lump of boat for a 5.2 meter boat just under 1.5tonne full of fuel, what sort of cat have you got?

Ian

[Smithy]

Len,

the hight thrust is to get the 25" leg over a standard 20" one. I think the Merc EFI 60s had the option but the high thrust Yammies were working out cheaper.

Ian,

I dunno but Fred and Michelle said to go for it. I know people like Stessl and that used to give you new builders plates for upgraded motors and stuff pretty easily if you talked them into it. Len's cat is one of those Raider Cats Nobbsy used to make.

[Noelm]

you will be very lucky to get ANY cat to plane on one motor regardless of HP, it just does not work with the motor on the side, so just be prepared for a slow trip home with a single should one fail for whatever reason.

[Smithy]

Here it is with the 90s.

[Deiter]

Here it is with the 90s.

Hmmmmmm......very nice. Got any more pics of that fish Smithy.

[couldbe]

Hey all,
Thanks for your help. I have finally bought my first 5.2m Kevlacat. I will pick it up on the weekend and head straight out into the deep blue see and hope that it will bring me home safely. I checked the mod. plate and the 5.2m is rated to 90HP max but I dont know what weight it is. I not going to repower her straight away but will put a few more hrs on the motors instead.

Thanks again and i will see you ont he water!!!!!

Daniel

[Smithy]

Chuck us a picture of your rig. Where did you find it?

[freddofrog]

Joining a bit late in the thread but the 1994 5.2m KC (Pro Sports) I bought came with 90hp 2st yammies @ 126kg ea. I checked with KC themselves and they said the 90st were fine.

Not sure if they are over kill or not but the max I can do so far is only around 33knots at 5,000rpm, so not too crash hot. She does however cruise very easily on around 20-22knots @ only 3600rpm, like they're barely working

cya
ff

[Noelm]

fredofrog, are you saying then that you only get an extra 10Knots for 1400 RPM increase?

[freddofrog]

When you put it like that it sounds quite sad doesn't it. I'm sure there are things I can do to get more speed but I just need time to play with it. At the moment though I'm more focused on setting the boat up to my tastes, I'll worry about speed later