KCHOTBOAT

Finally got the boat done but can't get it to plane out. Here is my problem. My HTM cat came with a IMCO drive extension like the ones land and sea makes. I no longer have it. This last weekend was the first time I had the boat on the water in almost four years. When I bring the motor up to 2000 rpms the boat will not plane and the prop blows out. I am thinking my X dimension is way to high. With the drive all the way down the prop shaft is still higher by about three inches than the sponsons. What is the correct height? I looked at spacers and was surprised on the $ amount.

tbanzer1

I have an sr24 and its touch to tell exactly but I would say the centerline of the lower units prop shaft is right at the bottom of the sponsons or a little lower. By the way I was the one who was in contact with you for several months interested in buying your boat. Glad to hear you finally got the boat done, I bought a 2000 sr24 about 6 weeks ago. If you need any exact measurements you can call me @ 716 549 0260 regards Tom.

KCHOTBOAT

I may try and call you this week. I did try a different prop I had and it does come up to plane now. But sure I need to lower the drive some.

zt260

What props have you run? Many cats like high drives and 5 blades.

KCHOTBOAT

I first put on the Hydro 4 blade prop I use to run on the boat and it would just blow out. I then used a outboard 4 blade with more of a rounder blades and it planes out now just takes a little time to.

zt260

Do you have any numbers? gps speed, rpm, ratio, and pitch

I slip a bit at 22mph before I plane, but the top end is much better with the higher X dim, and a properly labbed 5 blade maximus.

KCHOTBOAT

I don't have any real numbers yet since the motor also is new and breaking it in and getting it jetted correctly. I was doing in the low to mid 70's turning 4000 rpms with 1:36 gears and a 26 pitch foour blade.

zt260

You must be off a little on those numbers otherwise your slip would be around 0%. Is that speed on a GPS?

If your anywhere around 10% when your able to check it precisely. I would not go down. Rather lab what you have or go 5 blade.

KCHOTBOAT

I am thinking about going with a 5 blade. I need to do some testing this weekend with a GPS.

Pwrbt33

iTrader: (2)

I built a 30' Motion for a customer and I had to come down on his to make it "user friendly". I remember endimg up at 1" up from the bottom with no boxes. I also used IMCO Extreme drives. I to ended up with 5 blade props. Its great for him because he dont have to "drive" it to get it on plane. Before he really had to work it to get it up.

Just my .02.

John S.