'69 Mark Twain Tri Hull 160 Mercruiser Trim Pump Issues...Hair Pulling Time

[painthorsman]

Hi Everyone, I'm new here and pretty new to the I/O world. I bought a 69 18' Mark Twain tri hull runabout this past weekend. Went and looked at the boat, we fired it up on the muffs... engine started up instantly and ran smooth, all gauges working, trim went up and down fine, indicator gauge on the dash worked great... in all, everything worked as should... only issue is the vinyl on the seats and engine cover are shot and there is a couple of small soft spots in the floor in the drivers seat area. The only other thing I could find is the rubber exhaust bellows has a small tear in it.

Now the hair pulling part... I get the dang thing home and re check everything and suddenly the tilt trim pump wont work. It is in full up ( out ) position. If you click the rocker switch up... solenoid clicks, if you click it down .. nothing. I checked with a test light.. switch sends power out properly both directions, but the solenoid ( single ) only clicks in up... not in down. Motor doesnt run either way.... Battery is hot enough because it will start the engine.

When I apply power to the large green wire directly...as it shows in the Mercruiser manual I found online... nothing happens. Could the trim pump motor take a dump that suddenly in the trip home? It sounded and worked great when we initially looked at this boat.

Engine / Outdrive is a 160 6 cyl Mercruiser ( 250 cid Chevy ) The trim pump is a large all metal reservoir black Mercruiser Full Power Tilt with a single solenoid on the front of it. Any help or ideas on why this suddenly isnt working would be appreciated.... or if it did take a crap on the two hour drive home for some reason... where to look for a replacement trim pump. Like I said earlier... I've had gobs of outboards but not I/O boats.

 

[Bondo]

Re: '69 Mark Twain Tri Hull 160 Mercruiser Trim Pump Issues...Hair Pulling Time

Hi Everyone, I'm new here and pretty new to the I/O world. I bought a 69 18' Mark Twain tri hull runabout this past weekend. Went and looked at the boat, we fired it up on the muffs... engine started up instantly and ran smooth, all gauges working, trim went up and down fine, indicator gauge on the dash worked great... in all, everything worked as should... only issue is the vinyl on the seats and engine cover are shot and there is a couple of small soft spots in the floor in the drivers seat area. The only other thing I could find is the rubber exhaust bellows has a small tear in it.

Now the hair pulling part... I get the dang thing home and re check everything and suddenly the tilt trim pump wont work. It is in full up ( out ) position. If you click the rocker switch up... solenoid clicks, if you click it down .. nothing. I checked with a test light.. switch sends power out properly both directions, but the solenoid ( single ) only clicks in up... not in down. Motor doesnt run either way.... Battery is hot enough because it will start the engine.

When I apply power to the large green wire directly...as it shows in the Mercruiser manual I found online... nothing happens. Could the trim pump motor take a dump that suddenly in the trip home? It sounded and worked great when we initially looked at this boat.

Engine / Outdrive is a 160 6 cyl Mercruiser ( 250 cid Chevy ) The trim pump is a large all metal reservoir black Mercruiser Full Power Tilt with a single solenoid on the front of it. Any help or ideas on why this suddenly isnt working would be appreciated.... or if it did take a crap on the two hour drive home for some reason... where to look for a replacement trim pump. Like I said earlier... I've had gobs of outboards but not I/O boats.

Ayuh,.... Welcome Aboard,.... Check, 'n make Sure the pump has a Solid Ground connection,....

Ya need a full circle circuit for electrical stuff to work,....

Also make Sure both the Positive, 'n Ground circuit Connections are Clean, Shiny metal Clean,...
Then grease 'em to keep 'em that way,...

 

[painthorsman]

Re: '69 Mark Twain Tri Hull 160 Mercruiser Trim Pump Issues...Hair Pulling Time

Hi ... Thanks for the quick comeback All connections appear clean... took em all apart and checked n put em back together... funny it worked great when I went and picked the boat up in Lebanon MO on Sunday... Monday morning... it suddenly doesn't work at all.. there is power from the red wire in the trim harness feeding the dash switch, then back down to the plug in on the motor when switch is activated each direction....solenoid clicks in up position... ( I think the solenoid isnt used for down because it takes less current to go down? ) Maybe I'm All wet there? At any rate... it worked great during initial pre buy inspection of the boat.... then doesn't do squat the next day when I'm tinkering and re checking everything...... Frustrating to say the least... but then thats part of owning a boat... right?

 

[Bondo]

Re: '69 Mark Twain Tri Hull 160 Mercruiser Trim Pump Issues...Hair Pulling Time

Hi ... Thanks for the quick comeback All connections appear clean... took em all apart and checked n put em back together... funny it worked great when I went and picked the boat up in Lebanon MO on Sunday... Monday morning... it suddenly doesn't work at all.. there is power from the red wire in the trim harness feeding the dash switch, then back down to the plug in on the motor when switch is activated each direction....solenoid clicks in up position... ( I think the solenoid isnt used for down because it takes less current to go down? ) Maybe I'm All wet there? At any rate... it worked great during initial pre buy inspection of the boat.... then doesn't do squat the next day when I'm tinkering and re checking everything...... Frustrating to say the least... but then thats part of owning a boat... right?

Ayuh,.... As with Everything in life,... it works, til it Don't,....

It's 45 Years old, ya gotta expect Problems,...

 

[harleyman1975]

Re: '69 Mark Twain Tri Hull 160 Mercruiser Trim Pump Issues...Hair Pulling Time

Had same problem. turned out to be the trim motor on mine. try tapping on the motor assy a few times while a friend is applying power. FYI this motor will be a bugger to replace. rebuild is best option.

 

[redneck joe]

Re: '69 Mark Twain Tri Hull 160 Mercruiser Trim Pump Issues...Hair Pulling Time

welcome. I bought my first 'adult' boat in Osage Beach, 66 'Twain.

re: trim. on my latest love, I had the same issues and it was a connection on this thingie:

side note - in Lebanon MO, you ran on muffs - WINTERIZE or keep in garage with a heater on the block. Yer gonna get cold again real soon. Lost my 'Twain first winter....

 

[haulnazz15]

Re: '69 Mark Twain Tri Hull 160 Mercruiser Trim Pump Issues...Hair Pulling Time

The easiest option is actually just to replace the whole assembly with a used or reman'd unit. Plenty of them on eBay. Heck I even have one I pulled out of a Webbcraft last year just sitting on the shelf if you're interested, but I'm not sure on the solenoid arrangement.

I had mine go out in the '76 Twain a couple of years back, and didn't feel like trying to get a shop to redo the motor windings.