T's GF12

[Prarie Dog]

26.7 mph out of a 14 foot boat with 833 lb total weight doesn't seem too bad to me. If I can manage 20 mph with a passenger in my FS14 I'll be happy.

Going by what I experienced with mine and what months of looking for a 30 here's what I discovered. The 20hp 4 strokes are available used all over the place because they have a deserved reputation for not being very powerful. According to the guys at Bridge City Prop, the problem with the F20 is it has the same gearcase as the 10HP. It doesn't have much gear reduction nor does it have room to swing a very big prop, so what happens is they are tough to prop in marginal applications. If the hull is slightly overloaded or has a little more drag for a variety of reasons the boat won't run to plane. I have a 9 pitch blade for my F20 that had the cup changed three different ways and it would never plane. The guy told me when I first called that I didn't have enough motor for the boat/gear reduction/prop blade area etc. He also told me that the F20 was considered a dawg by guys that were experienced with the old 25HP 2 strokes. These guys aren't happy with current regs that have put us in this place. Longer wider boats that will handle the weight of the heavier 4 strokes don't suffer as much as smaller narrow hulls.

[jaydillyo@yahoo.com]

I hear ya. If the F20 doesn't do it, I'll have to sell her... or build another boat that it can power.

Should I need to get something else, I have my eyes on the new Suzuki DF30A. 30hp, electric start, ptt, 158lbs. I'm anxious to see some actual reports. I'm going to stick with 4 stroke as I'll be doing a lot of canal cruising at slow speed. Of course I want to get the boat up on plane with a passenger though.

http://www.suzukimarine.com/Product%20L ... DF30A.aspx

So ends the thread hijack.

[timoub007]

Hi PD,

Been a long time. Merry Christmas and Happy New Year. Let me know how this thing is running and if I can offer any insights. I'm way behind on reading these boards so I don't have a clue where you are other than seeing you got a "better" motor. (I put a 25 ETEC on my GF16T)

Tim

[Prarie Dog]

Hey Tim, Happy Holidays to you too. The GF 12 needs to have the motor raised and perhaps a wedge. I had a small manual jackplate built for it that doesn't have enough height to get the job done, that plate also has some setback that isn't good for this setup. I recently bought a cherry picker to hold the motor at the right height so we can get some good numbers on exactly what we need so I don't build another plate that's unsuitable. In addition it's been very cold here so the shop isn't exactly a nice environment to work in. When the weather warms some we'll get back on it. The 30 Etech is nice.

[jacquesmm]

Hi PD,

Been a long time. Merry Christmas and Happy New Year. Let me know how this thing is running and if I can offer any insights. I'm way behind on reading these boards so I don't have a clue where you are other than seeing you got a "better" motor. (I put a 25 ETEC on my GF16T)

This is about a heavily modified GF12: a tunnel with what looks like a step in it has been added and also sponsons.
It does not mean that a regular GF12 needs that much HP: I have seen one planing easily with a 10 HP.
I don't want people to think that a GF12 needs such a big engine.
This is an experimental boat and I wish they'll get the boat running but I can't help much.

[deuce_454]

erhm... im sorry to be the one to suggest this... i have a s suspicion that im not the only one to think this.... and i mean no offence by this... but how about building different boat ?

even just a GF14 built with emphasis on keeping the weight low will in my humble opinion fit your bill much better than your experiment ... it looks heavy as is and adding a bigger engine will make it sit even lower... negating all the work with the tunnel...

im not trying to piss anyone off and it looked like you are having a blast building this thing.... but it looks like it has gone thru a lot of design iterations and my suggestion is to build a 2.0