Should I lower my motor?

[commonarcwelder]

Alright guys...I have an 88' Allison XB2002 with a 96' 225 Evinrude/Low water pickup/31p chopper prop. My problem is this; When I get on plane @ about 4000 RPM the boat starts rocking side to side (Bad!!!!). It litterally scares the S!!t out of me it's so bad. I got it up to about 5500 RPM earlier today and didnt think I was gonna regain control! I tried trimming it every way imaginable and nothing stops it. To me motor maybe a little high.........It has a 10" offset jackplate. I got this boat 2 weeks ago and have put it on the water 3 times and have made no adjustments. Any suggestions on how to stop this?

 

[jtexas]

Re: Should I lower my motor?

good article here about chine walk:
http://www.kencook.net/Chinewalk.html

 

[commonarcwelder]

Re: Should I lower my motor?

Good article, but there is no learning to drive it to keep it from "Chining". I'm on plane nearing 4000 RPM's no matter where its trimmed and it gets crazy. Gotta literally feather the throttle down and "walk" it down to about 3000 RPM's for it to settle down. Possibly lower the motor. Maybe? Thanks for the help.

 

[iwombat]

Re: Should I lower my motor?

where does the anti-cav plate sit in relation to the keel?

 

[commonarcwelder]

Re: Should I lower my motor?

Cavitation plate sits roughly 7 inches above the bottom of keel. With motor leveled out in relation to the boat; where the prop nut meets the prop to keel is 47 inches.

 

[iwombat]

Re: Should I lower my motor?

I'd say it needs at least 5" of lowering.

 

[commonarcwelder]

Re: Should I lower my motor?

Yea I was thinking the same thing. I got it from a guy that drag races a Mirage. He told me he didnt have much pedal time in the boat. But said it was "scary fast". Right now its plum scary and not even running that fast. I appreciate your advice and will start lowering it an inch at a time to get best results. Do you think maybe it has too much offset on the jackplate? (10") Thanks!

 

[tashasdaddy]

Re: Should I lower my motor?

start with lowering it. then go from there. Dhadley hopefully will chime in on this one.

 

[ezeke]

Re: Should I lower my motor?

Before you lower the engine, you might want to try moving the thrust rod out a hole or two. Sounds like you may be forcing the boat to plow, which can cause the same kind of symptoms at speed.

 

[72SideWinderSS]

Re: Should I lower my motor?

You need more seat time to learn to drive the chine, it take time to learn. Lowering the motor will more than likely aggravate the chine walk. Start slow and easy and move up in speed when you can control the walk at that speed.
Again it just take time and practice to learn.

 

[commonarcwelder]

Re: Should I lower my motor?

uPDATE: Cured the chine!!!! Dropped the motor down 1 inch at a time. At a total of 3 inches all chining is gone and I am now in control...Havent really opened it up yet.....had my wife and kids in the boat.....5000 RPM's are now not a problem!!!! Thanks guys for the help! When I grow up I wanna be more like IWOMBAT or TASHASDADDY or EZEKE.......

 

[commonarcwelder]

Re: Should I lower my motor?

Maybe ya'll can help me with my trim problem and lower unit questions in my other threads?