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Razor
07-11-2003, 09:11 AM
I recently bought a 1998 Classic 18, it has a 305, 2bbl and does not have through hull exhaust ot trim tabs.

When I have 4 average sized adults in the boat, it does not want to get up on a plane unless I move someone up to the front for a couple of minutes to offset the weight distribution.

I talked to the guy at the Donzi dealer and he said "Yeah, that's always been a problem with the 18, it doesn't have enough hull displacement to allow a quick or a good plane with that kind of weight".

Is this correct? Is there anything I can do? I hate eating the wake of Bayliner 18 bowrider outboards with entire families on board as we are "plowing" through the water.

Thanks in advance for any help...

Ed Donnelly
07-11-2003, 09:20 AM
Sounds like you are running a 3 blade. If this is so,a 4 blade will make a world of difference..Ed

Ed Donnelly
07-11-2003, 09:22 AM
Sounds like you are running a 3 blade. If this is so,a 4 blade will make a world of difference.You are trimmed all the way in on start up I hope..Ed

mattyboy
07-11-2003, 09:24 AM
I would look at your prop first, trim next, and then lastly look at getting the 305 tweaked a lil


Matty

riverrat
07-11-2003, 11:39 AM
Razor, I think a 305 should push that boat just fine. I'm running a 350 mag mpi & it leaps out of the water. What prop are you running? a three blade merc mirage "19 or "21 should work fine. be sure and get a vented prop. that will help to get it spinning.

Riley
07-11-2003, 12:38 PM
What prop are you running? I had a 305/thru hull set-up in my 1999 18', and never had trouble getting on plane, even with a boat load of people. I ran several different 19" and 21 " props and they would all get the boat up on plane, granted that some worked better than others. Are you tucking the drive all the way in when you are trying to plane out?

GeneD
07-11-2003, 03:08 PM
Well, when I had the 305 in 007 it had a top speed of 56 MPH. It didn't like a boatload of people that much is certain, but it did get on plane pretty good.
Listen to the other folks here, they have some good ideas on what your problem is.
I'd be checking that prop.

Ranman
07-11-2003, 03:23 PM
A 305 2bbl is not going to be a rocket, but you should have no trouble getting her up on plane with a boat load of passengers. Again, make sure the trim os tucked all the way down.

Like the others here said, the first place to check is the prop. Make sure you have a good prop that is somewhere in the correct pitch size. If this turns out OK, I would think you are down on power considerably and I'd start to look at the engine to make sure it's making good power.

Get back with us on the prop. If it's good and we have to troubleshoot the motor, try to provide as detailed info as possible and someone here will get you going.

Razor
07-12-2003, 08:27 AM
Yes, it is a three blade stainless prop. I'm defintely going to go to the local prop guy and get a 4 blade set up and see if it helps.

Thanks a lot, I really appreciate all the input from you guys. That's totally cool!

I'll let you know what happens.

Thanks again!

Cuda
07-12-2003, 10:40 PM
Razor, I just saw where you are located. We will be expecting you to be at the next SEADOGS get together! :)