Git Yur tape measures out...

[Shnick]

ok, im wondering about the placement of this here engine... the boat is 29 1/2" long, planning on a K&B 3.5cc, 16 oz tank...

whats the distance on YOUR boat from the transon to the plug???

ive heard 33%, 25%, and 28% of total length...

i dunno...

Thanks, Shnick

 

[Ron Olson]

Are you racing this boat or using it for fun or both? 16 oz. is a lot of tank if you're racing it, 8-10 oz. is plenty.

It used to be that 27-28% was about right, now some people are running the weight a little farther forward, as much as 33%. Start at around 27% then see what the boat likes. I like to jump a small wave to see how level it flies to determine mine. If you are going to race, you might want to make it a little tighter on the water, they loosen up in race water conditions after the course has a few laps on it with 6 boats.

 

[Ian Inverarity]

Shnick,

I presume you are talking about a mono? Most monos are set up with the flywheel of the engine approximately at the CG. The CG is more important than the engine position in general.

Having put together a few monos over the years, one of the things I have found is that one CG does not always apply to different hulls. A particular design suits a particular CG. In you case I would start with about 28% and adjust it from there if it needs it.

Ian.

 

[Ian Inverarity]

Ron is right about the tank too, 8oz is plenty for a 21!

Ian.

 

[nitrotoys]

Shnick,

What boat are you setting up??

Just a guess, a Seaducer?

If it is, I will take measurement of my ducer.

I have a .21 CMB. So should get you close.

If not, I went with 28% CG, seems very good, with a 14oz tank.

Now guys, am i right or wrong, you set the CG up DRY WEIGHT RIGHT????

 

[Ian Inverarity]

Nitro,

I set up my boats CG without fuel. My last couple of monos had the tank next to the motor, so the CG difference between full and empty was not that great. But I have changed my current mono to put the tank at the back next to the radio box. Thus as the boat gets lighter as the fuel load comes down, the CG moves forward to compensate. Seems to work okay.

Ian.

 

[nitrotoys]

Ian,

I Just went by the Seaducer where the tank was in the front of engine. Now if i put the tank in the back of the boat, Would i have to move my motor forward some then?

I am open to try differnt things with the boats, But to do so need more info.

Some day, Some way, the boats will ALL Be set up to my likings and i will not have to change around everything on every new idea.

Some work, Some dont, Dont know if they do or not unless you try it.

 

[Ian Inverarity]

Nitro,

If you are setting up a Seaducer, I would stick with what the instructions say.

My boat is a 46" Kingcraft, and I was trying to reduce the tendancy for the boat to start riding lighter as it used more fuel. With a 20oz tank, it looses a fair bit of weight as the tank runs out.

I am always changing stuff to try to find the optimum performance! This boat is on it's 3rd motor, 2nd pipe, 2nd strut, 3rd tab configuration, 3rd tank configuration etc! :

Ian.

 

[Shnick]

its not a seaducer, its just a mono hull i got from hong kong, i call it "Project Lemon" lol its just for fun, hence the reason for the larger tank, more run time... just getting ideas before i blow money on parts...

thanks, Shnick