Strange Trim Issue

[Chris Droke]

Yesterday I was out on Reelfoot Lake and noticed some strange trim issue. Reelfoot is notorious for it's stumps and most of the time you just idle with the motor trimmed up as far as possible. While trimmed up high I increased the throttle and the motor came down without me hitting the trim switch at all. It appears to be holding position while I'm on plane, but I have never had one do this before. I was thinking that maybe the trim cylinder is having fluid leak by internally allowing the motor to pull down? If this is the case then why does it not do that when on plane running WOT? Also my cranking gremlin showed up again yesterday. I have checked wiring and cleaned terminals, replaced the main fuse holder to the engine and everything was going well. Went to crank up and nothing, just like it has the battery removed. The guages come online when you turn the key but no starter engagement. All of the sudden after continuing to attempt a start if fires up. Any ideas on these two problems?

 

[Dan J.]

Thrust defeating trim. Your pump may be going bad and internally bypassing under load. Unless you see fluid leaking or have air trapped in the pump, that is where I'd start. Your starting issue could be the bendix in a bind on the flywheel, solenoid going bad, ignition switch going bad, or as simple as a corroded connection at the starter leads (big 6-8 gauge wire at starter) or a switched lead under the cowl at the solenoid, ignition lead(s) at the back of switch on the console or a weak main battery connection (like corrosion or a loose terminal). Throw away the wing nuts on your batteries and lock down all of your connections after cleaning with the appropriate SS locknuts. Good luck!

 

[Chris Droke]

Is there anyone out there that rebuilds trim pumps. If I'm correct the trim consists of a pump and an electric motor? Can you send the pump out for overhaul or would you replace with a new one? I have checked and feel like the connections are good on the starter. I think I may put a new ignition switch on and see what happens.



Thanks

 

[Dan J.]

A lot of hydraulic shops will rebuild a pump. Check with your dealer and see if they know someone close by. If not, call C&O Marine in White Bluff. They'll get you fixed up. Good luck!

 

[Lamar Gilbert]

I had a similar problem starting my 75 last month. Had to replace the starter solenoid. A real simple change out.

 

[David Munaretto]

I believe that is a feature, if you are trimmed too high and give it too much throttle it automatically trims down on mercury motors, you were probably up above where the pistons meet the plate and gave it too much throttle

 

[Dan J.]

A V6 will drop to the rams, but your 90HP should bow rise that hull like an Apollo liftoff when throttled up and trimmed out, unless something is a miss. Good luck!

 

[Chris Droke]

Thanks lamar, i had not considered the solenoid. Sometimes it acts like the starter is dragging so maybe you are dead on with the solenoid.





I agree Dan J, I owned a 170 back in 1993 and it never trimmed down, just pushed the nose up.





Thanks to all who respond. I can't say enough about how helpful all the input is when trying to fix a problem. I don't have a local dealer worth a dime so I try to do most of it myself.

 

[Scott Hammer TOXIC]

Also don't forget to check your kill switch. Could be corroded or bad connection or bad switch. Always start simple and work your way up.



TOXIC

 

[Chris Droke]

Changed the starting solenoid today and what a difference. The starter now turns over like it has 24volts instead of twelve. I think this may have fixed the starting problem. I did ask the local shop about the trim and they said it was designed to do that. I'm no expert but it did not do it until Saturday so I have to respectfully disagree with them on this one. I will check the kill switch too I had not really considered it. It's hard to remember all the possible sources to the problems. Glad you all are out there with experience to help out!

 

[Chris Droke]

WELL I STAND CORRECTED. ACCORDING TO THE MANUAL ON MY MOTOR ANYTIME YOU ARE TRIMMED WAY UP AND EXCEED 2000RPM THE MOTOR WILL TRIM DOWN AUTOMATIC. MY APOLOGIES TO THE MERC. MAN AT THE SHOP ON THIS ONE.