1997 mariner 60hp bigfoot power trim issue

[trent0416]

hello. the power trim on my pontoon works, but when under load seems to fall on its own. any help? thanks

 

[RRitt]

Re: 1997 mariner 60hp bigfoot power trim issue

Do you have an oval or square base on your trim motor?
Oval base is notorious for trim limit spring compression. The spring just compresses with age and has to be replaced. It is a design flaw manifested on 40HP+. If so, then a new trim limit kit should give you another 10 years.

If you have a square base, then it should not drift down past 1/3 no matter what you do. About 1/3 way up there is an internal bleed-hole that prevents engine from lifting any further with prop spinning. Above this point, bleed down is usually just a spring weakened by rust or age. Below this spot the spring has no effect and bleed down could be a lot of things. You could end up spending hours and $$$ chasing problems and throwing parts at it. Better to just have it rebuilt or replaced. Ebay is good source.

 

[trent0416]

Re: 1997 mariner 60hp bigfoot power trim issue

thank you. as far as the rebuild is concerned, is this just a new seal kit or what does this consist of? thanks again!

 

[RRitt]

Re: 1997 mariner 60hp bigfoot power trim issue

i don' think mercury sells a pump rebuild kit. I think you have to buy a new pump & manifold assembly from them. It's not a diy friendly repair.

 

[trent0416]

Re: 1997 mariner 60hp bigfoot power trim issue

just wanted to follow up with my trim issue. i was going through boat for this river season and was looking at the trim. if i run the trim from the switch on the motor so i can see it operate, when going up it seems to catch a void in a spot or 2 on its way up. so with the switch held consistently in up position the trim will move up perfectly and all the sudden stop moving for a split second then start right back moving up again. the entire time the switch is depressed and the trim motor continues to run the trim just stops going up in a couple areas for a second before continuing. i will double check whether i have a square or oval base, but i believe the bottom of the trim motor is square where it bolts down. thanks again!

 

[RRitt]

Re: 1997 mariner 60hp bigfoot power trim issue

a pause in the middle is not uncommon. Mercury uses two pistons that separate from each other as the shaft extends past 15 degrees. A seal kit will probably not fix your failure to hold issue. Try tilting your engine up in driveway and leave for a few hours. If it drifts down then a seal kit will fix. It is holds then your problem is in the regulators and bypass valves.

Of course, it really doesn't matter where the problem is. If you go in to fix seals then there's no excuse to not rebuild regulators. If you go in to fix regulators then there is no excuse to use old seals. Either way, everything gets fixed regardless of problem.

 

[trent0416]

Re: 1997 mariner 60hp bigfoot power trim issue

so yet another trim issue! the tach quit working on this boat, and the trim gauge has always showed full up. bought a new set of gauges and installed them today. everything works great EXCEPT for the trim gauge. it is still in full up position and will not change when operating key or trim. didnt troubleshoot much, but the power and ground to gauge is there as it does light up as required. not sure what to check next. should i trace the sending wire from the gauge to the rear? what area should this wire be running to? it does go out the floor heading to rear, but didnt know where this typically runs to. thanks again