Merc 165 in line 6 - trim operation and limit switch

[David Foe]

I am new to out drives but I am having fun with my old but new-to-me 1973 starcraft American with an in-line 6. Three (related) questions...

(1) The power trim dash control has a three button control labeled up - up/out - in . From the manual I think I understand that "up" and "up/out" pushed at the same time moves the outdrive into "trailer" position while pushing "up/out" alone is for trimming up and pushing "in" is to trim down. Right?

(2) At the moment my drive doesn't always like going up but I know that the trim limit wiring is brittle, corroded, and actually bare where it passes near the engine block on its way to the harness so it has to be replaced. How do I access the switch itself -- do I have to remove major parts of the drive?

(3) Assuming that I am right an it is difficult to reach the switch, is there anything wrong with shorting the trim limit switch and happily running the boat that way?

Thanks!

David

 

[ziggy]

Re: Merc 165 in line 6 - trim operation and limit switch

you do understand correct.
my trim limit don't work either. the switch is nla + impossible (major disassembly) to go get to R&R it even if there was one available.

either do what ya say in number 3 or. i haven't done anything. i just use trailer function. pushing in/out + out together to perform all trim/trailer functions.

 

[windsors03cobra]

Re: Merc 165 in line 6 - trim operation and limit switch

Yes the functions you describe sound like you understand it. I have a 77 American and it has the same set up "star-trim"
I re-did my limit and sender last year when I did the bellows and am happy I done em but they are useless for the most part. I am always trimmed down BTW but I am just a low speed cruiser.
I agree with Ziggy, forget splicing and just use the trailer switch to make it go.

 

[ziggy]

Re: Merc 165 in line 6 - trim operation and limit switch

I am always trimmed down BTW but I am just a low speed cruiser.

always?

i'm a slow speed cruiser too, but alas, i do get a heavy right hand once in a while. trimming out for the little extra performance and better handling... + ya gotta find out if ya can reach that magic number (4300) to be sure she's in proper working order sometimes...

 

[David Foe]

Re: Merc 165 in line 6 - trim operation and limit switch

Uh oh! Maybe I don't really understand my problem. From ZIggy's comment, it seems that the trailer function (pushing both buttons at the same time) should still work even if the trim limit switch is permanently open but my formerly intermittent and now pretty much always problem is that neither the trailer function nor the up trim functions work.


I leave the boat in the water and, when I use it now, I, like windsorcobra run it with the engine trimmed all the way down.

On a completely separate topic -- what Oil pressure do you guys see on your in-line 6? Is 15 psi too low? Is it adjustable?

 

[ziggy]

Re: Merc 165 in line 6 - trim operation and limit switch

don't know if this will help, but check out achris's post #3 from this thread.. http://forums.iboats.com/showthread.php?t=383053

neither the trailer function nor the up trim functions work.

that would be a problem there.

assuming elec. the s/m state for will not trim up or out.

limit switch open or disconnected
defective push button(s)
defective trim motor solenoid
defective trim motor field winding (''up'' circuit)

another thought, if it think's it's in reverse, trim won't work.

get yerself the oem service manual. there's a pretty good trouble shooting guide in it..

 

[windsors03cobra]

Re: Merc 165 in line 6 - trim operation and limit switch

Oil pressure. well hmm 15 hot at idle is fiine and 30 while crusing is good I would say. I have 10 at hot idle and 30 at cruise and have no issues.

The intermitent trim could be a bad solenoid, I know my 33 year old original went out last year. I used a $9 Ford starter solenoid as Mercury said their part was $60 and a week to get.

 

[ziggy]

Re: Merc 165 in line 6 - trim operation and limit switch

gee, i'm having a hard time remembering what my gauge says (guess i'll have to go for a boat ride today, i have reason now, ). so i went and looked at some pics i've taken of my gauges. best i can see. i'm getting 20psi a little above idle and 40ish @ around 3800 rpm..

 

[brhodes]

Re: Merc 165 in line 6 - trim operation and limit switch

I started out the season without my limit switch working. Had to do the bellows and replaced the switch then. As was stated, I don't think they are necessary, but I would note that when I adjusted the limit switch per the manual, I was surprised by what little amout of trim is allowed. Just be careful not to go very far up at all when under power. Have fun.

 

[David Foe]

Re: Merc 165 in line 6 - trim operation and limit switch

Great information! Thanks everyone.