Tunnel removal

[Syd Marsden]

I have the same boat and when researching it, Mr Furnell told me that it was there to help reduce the chance of a blow over. With not knowing much about engine set up and using a stock mk25 powerhead on a quickie lower unit and mid with the 16/21 gears I have had it up to 49.6. Still a far cry when it ran in the mid 80's back in the 1980's with the merc 44.

[johnsonm50]

After reading all this the 1 thing I agree most with is to try it before you change it. Not big on experience here but I have raced 3 hydros in CSH so far. A tunneled like yours, a straight [no tunnel or step] & a step currently. So far Ive done best with the step, but stopped racing the tunnel while still very green. Of the 3 the tunnel is the one I've never ended up 'out' of. It is fast, airy but very forgiving. Ive hunkered down at speed several times thinking it would dump me but no. Fast is of course important but good driving & almost fast can work too. I'd call it worth a try, you can always fill it later. Good Luck

[Dew1us]

Leave the tunnel there. IF you change it to non-tunnel you risk making the change for the worse.

Dad designed it for the purpose of stability at high speeds.

[JBM]

Thanks to all for the great input on this. I did run this boat once with the 125 on it, and it was a nice ride, until my chamber broke in half. I was asking questions on how to set the motor up on a tunneled boat and it was mentioned to fill it in. The bottom is very rough and I was planning on resurfacing it anyways. I will take the advice of leaving the tunnel in and just resurface it.
I also noticed a hook in the tunnel. Should that be flattened out like the bottom?
John

[ZUL8TR]

tunnel hook?

Thanks to all for the great input on this. I did run this boat once with the 125 on it, and it was a nice ride, until my chamber broke in half. I was asking questions on how to set the motor up on a tunneled boat and it was mentioned to fill it in. The bottom is very rough and I was planning on resurfacing it anyways. I will take the advice of leaving the tunnel in and just resurface it.
I also noticed a hook in the tunnel. Should that be flattened out like the bottom?
John

Do you mean a hook if a straight edge was laid fore aft from where the tunnel starts to the transom and looking at the space from the tunnel plywood to the straight edge and the tunnel plywood is not a straight line?

Explain or show a pic with the straight edge.

[mercguy]

[QUOTE=JBM;235348]Thanks to all for the great input on this. I did run this boat once with the 125 on it, and it was a nice ride, until my chamber broke in half. I was asking questions on how to set the motor up on a tunneled boat and it was mentioned to fill it in. The bottom is very rough and I was planning on resurfacing it anyways. I will take the advice of leaving the tunnel in and just resurface it.
I also noticed a hook in the tunnel. Should that be flattened out like the bottom?
John[/QUOTE

tunnels are for wimps!!!! Don't play dumb John......we all know what you are capable of....