Crestliner Fishhawk Issue

Hello all. Maybe someone out there has an idea on this. I have a 97 Fishhawk 1650 I bought used this past summer with a 1996 75 Merc with a 21 pitch stainless LaserII prop. Boat rolls severely to the left at speeds over 27 mph. I've had the boat up 37 mph according to the GPS and it is a handful to say the least. At 37 I still had throttle left but this thing feels so unsafe I don't dare go over 30. If I'm alone in the boat it's not too bad but with just one other person sitting next to me it's bad !! I have to lean over the side to try and balance it out. The motor is straight and centered. With that said it is mounted an inch up, off of the transom. I have two 12v bats up in front (battery box, centered) There is nothing wrong with the hull, nice and straight. I have tried putting an lesser pitched aluminum prop on it and it still does it. I plan on dropping the motor down and trying that. If that does't do then I'll move it up. One problem with the Merq is that it automatically trims it's self all the way down at over 2,000 rpm. Would be nice to have control over it for rough water. Ideas? I know the newer fishhawks are wider now. Bad hull design? Thanks, Sideways in West Bend

I found my answer hopefully.... "Trim tab adjustment will have little effect reducing steering torque if the outboard is installed with the anti-ventilation plate approximately 50 mm (2 in.) or more above the boat bottom." I found this in the link that nihsif posted....Thanks! I checked mine and the AV plate is about a 1 1/2 in ABOVE the bottom of the boat!! it also said to have the AV plate 1.2-2 in below the hull and I can tell the motor was raised on the transom by the markings on the other bolt holes. looks like its time to go find out more info from a dealer and see how much its going to cost to have them lower the motor Thanks Bill

see page 64 for trim tab adjustment, page 40 for motor installation instructions http://www.mercury-marine.eu/cache/Documents/Mercury/SeaPro%2015/0/en-GB/DocumentFull.pdf trim tab adjustment should be same on any motor so, steers to right, adjust trim tab towards starboard, left, adjust toward port

Anybody have any thoughts?? thanks Bill

Recently picked up a 2000 1750sc with a 90 merc on it. I'm having a problem with it pulling to the right. I noticed that the motor has been raised on the transom, its 2 in. higher than the transom and when doing cruising it seems like the motor isn't into the water far enough and I was wondering if this could make it pull to one side! When its under power you can see the top of the fin on the motor thats just above the prop. It also looks like the motor was lower on the transom because the finish on the other bolt holes was scraped off! thanks Bill

Think I fixed it. After much forum searching this seemed to fix my list on plain. Moved one of the trolling motor batteries from the front bow battery compartment to under the console. (Bow Steer) Raised the motor up one set of holes. 2" above the transome now. (Cav plate too low) Switched from the 22 pitch Laser II prop to a 19 pitch Black Max. (Prop torq) Gets up on plain faster. Runs nice and level. Almost feels faster/quicker. Didn't have my GPS hooked up during the test run so not sure of my top speed but the max RPM's are now perfect per Mercs specs. No prop blow out in tight turns. Very stable ride now, felt unsafe before. Happy happy

No way of telling. Based on the info provided, your tilt/trim system might not even be serviceable in the eyes of Mercury. They change tnt systems faster than I change trucks (about every 3 years). So they stop making parts, and super-cede part numbers up to the replacement system. Those are $700-$800 just to show up in a box. Remember, guesses only cost more money in the long run. Get it looked at by a reputable repair shop. Might be a $90 fix, might be a $900 fix. Good luck. Give us an update when you get it figured out.

Thanks again Boat Doc. Boat's in storage now so I'll have to wait until spring to try your procedure. Given the info, what is something like this going to cost me to fix? Ballpark figure. Ken W.

It will "tilt" down. Tilt is the high volume, low pressure side of the pump. It's not tilting because of the RPMs, it is tilting because of the pressure. If your interpretation of the definition were true, you could run your motor on a flusher (over 2000 RPMs) and the motor would lower itself without anyone touching the electric circuit of the TnT. Try that see if it works. Hook up a garden hose and report back to me. TRIMis the high pressure low volume side of the pump. Trim is designed to hold the pressure of wide open throttle operation. It's two systems in one, yet completely different animals. Here's an easy test for you, without looking for open water: TILTthe motor up about 75% up, while the boat is on your trailer. Remove any transom savers or travel locks obviously. Have a person who is 200 lbs or heavier stand completely on the back of the motor and bounce up and down(both feet on the area the exhaust housing curves back away from the boat, above the prop) The motor should slowly leak down to about a 25 degree angle and stop. That stopping point is whereTRIM begins. If your trim circuit is working correctly, you couldn't put a heavy enough guy on there to get a proper trim circuit to leakdown. In temps under 50 degrees it may take a 1/2 minute or so. The trim circuit should kick in at about a level where the motor cover still has a forward angle. If it doesn't stop, and keeps going to the absolute lowest mechanical area it can, you have a pump problem. If it doesn't move at all, get a heavier friend.

Thanks Doc but. The Merc's manual actually states the motor auto trims down over 2,000 rpm. I thought like you said that there is a problem with the pump until I read that in the manual. The motor will stay in any position when off or under the magical 2000 rpm. 1996 2 stroke 75 Mercury. ????

"One problem with the Merq is that it automatically trims it's self all the way down at over 2,000 rpm. Would be nice to have control over it for rough water." There are no motors that automatically trim themselves down. Your trim pump (specifically the valve body) has a problem. Your motor must be running in the all the way down position, therefor creating your planed level issue. The deeper a prop goes in the water, the harder it twists the boat counter clockwise, or as you say left. Have your tilt/trim repaired properly. Then have someone go out on the water with you, and show you how to trim a boat on plane properly. The best candidate would be a technician from the repair shop.