Boat Builder Central

Venting the tunnel will cure much of the cavitation issues.

Not sure if you're looking for input on putting a tunnel in a GF, but if so you might learn from my build thread. Sponsons are going to be dictated by the swing of the motor from lock to lock. On the small transom of the little GF's I don't think you can make them very wide. You can also put an angl...

Yes, I believe the 15, 25 and 30 are all the same motor with different computer programing. I'm not really sure what the market is for a 150+ pound 15 hp, but someone must have made the case for one. As far as noise, I think it is about the same at idle as most small 4 strokes. I really haven't been...

I have an ETEC 25 on my GF-16 and love it.

You do know that ETEC's are not 4 strokes though right? That is why I bought mine.

They are about the same weight as a comparable 4 stroke, but the torque is amazing from this little motor.

Tim

Nice job Murry. Congrats and enjoy.

I realized I don't have any of the final performance numbers in my thread, and for that I apologize. Since the last update, wow over two years ago, I've made a couple of other tweaks. I had a couple of 3 cylinder 25 hp JohnnyRudes that were getting older (1996 & 2000) and starting to have miscel...

I apologize if I sounded a little sour in my last reply. Sometimes you just get tired of of repeating yourself, you know? I realized I don't have any of the final performance numbers in my thread, and for that I apologize too. Since the last update, wow over two years ago, I've made a couple of othe...

Click on the link in my signature.

It might be really similar to what you're looking for.

Look guys, this is one of the reasons that I don't reply often to tunnel threads. Very few other builders want to listen to my experience. One builder by the name of pita did vent his XF-20 tunnel and reaped all the benefits I've laid out. As far as the width, again what I posted is based on many ye...

I don't post very often any more, life takes up more time than it used to with my growing family. Let me start by saying that I am no nautical engineer or boat designer. I am an engineer and have quite a few years with tunnel boats of various designs. Search the forum for past posts by me though on ...