trim up not working, 1978 mark twain v180 merc165 I/O

[hpcma1]

Trim up not working , it has 3 button trim setup. bottom button trims down, top button trims up,, then you press top and middle button for trailoring. it raises for trailoring, but regular trim up doesnt work. first boat so if something has to be in some position for trim up tp work i wouldnt know. headin to lake this weekend to try and learn how to captain my boat. also previous owner says it doesnt go in reverse would that be just like a loose cable or???

 

[Bt Doctur]

Need to see a pic of the sides of the outdrive to see if it has a trim limit switch, the old type is NLA
cable adjustment, shift cable components, worn out shift spool in lower unit. could be lots of things. You have checked all the fluids, including the outdrive oil level?
engine oil, bilge pump operation both manual and automatic?
Get everything tested on land, get some flush muffs to run it on a hose

 

[hpcma1]

ok after lotsa research i think its the trim switch. i have 2 one on either side.and so far the trim gauge isnt working either. so i can imagine boths are bad. i've seen that i can just push both buttons(as if trailering the boat) to adjust trim. this shall be fun seeing as how ive never driven a boat nor know a thing about trim but i like to think of myself as a smart fella, and am gonna take it out to the lake to try and figure all of this out. worse case scenario, i end up using a trolling motor, taking off the trailer should be a hoot with no reverse, but hopefully all goes well. the reverse is cable driven i can tell that much will have to see when were on the water f i can get it fixed

 

[hpcma1]

ok after lotsa research i think its the trim switch. i have 2 one on either side.and so far the trim gauge isnt working either. so i can imagine boths are bad. i've seen that i can just push both buttons(as if trailering the boat) to adjust trim. this shall be fun seeing as how ive never driven a boat nor know a thing about trim but i like to think of myself as a smart fella, and am gonna take it out to the lake to try and figure all of this out. worse case scenario, i end up using a trolling motor, taking off the trailer should be a hoot with no reverse, but hopefully all goes well. the reverse is cable driven i can tell that much will have to see when were on the water f i can get it fixed

 

[stonyloam]

Holy moley! sounds like you are going to learn the hard way! I assume you have run the boat on muffs right? You have a few things that you need to do. Like the Dr says. Sounds like the PO was pretty negligent so you need to drain the outdrive oil and put in fresh gear oil. You pull both the top and bottom plugs to drain and use a pump to pump in fresh lower unit oil in from the bottom till it comes out the top. also if he neglected the shift cable, chances are that the waterpump impeller in the outdrive has also been neglected, so watch the temperature gauge like a hawk, any sign of overheating cut the trip short. The trim limit switch is on the port side..Good luck, let us know how it goes.

 

[pureinsanity]

I agree that it sounds like a trim limit switch problem. I replaced both switches on my 77 Mark Twain when I first got it. As for the no reverse, it could be a few things. I understand wanting to get your bout to the lake and enjoy it but man you glutting for punishment not getting problems resolved be for you go. Also Stonyloam was right about the water pump. You need to just replace it that way you know it's good to go.

 

[hpcma1]

ok well i see why yall thought i was nuts...sorry we was rushing to get out to the lake lol. first i bought the boat 2 months ago never been in on around a boat got a 1978 mark twain v180 for 400 with trailer. For 400 i had figured the trailer was worth it alone so he started boat and i bought it. well it need interior bad... Well i rip out interior and fall through the floor. so i start gutting, had to remove the stringers and all. only had 30 days to replace as i had made plans for 4th of july. im a mechanic by trade, and knew the engine was good., and im pretty good at fiberglassing. well 30 days runs out way to quick so idint have much time to test BBUUUTTT (as i forgot to mention) i had gone and bought a trolling motor just in case anything went awry. Boat ran like a champ. many compliments, no one could believe it was the old 78 boat i had bout will def need to upload some pics. now heres the bad and i will run other posts for these as they come time to fix. switch panel needs replaced, had to jiggle switches a bit to get things to work right. ignition is looseish so prolly gonna get a new one of them. trim never worked, but i did fine using the top 2 buttons(trailer) and to take care not to go to high. reverse doesnt engage just revs couldnt even tell where to start. no speedo, no trim gauge. no depth finder, and no night lights around gauges. i knew i had forward gear and nav/anchor lights, and i was determined...those were enough we were just fishin round and cruisin the lake. how hot should it of ran? it seemed to sit around 200. first to replace will be impeller, and trim sensors, then will move on to speedo, and switches.

 

[pureinsanity]

Sounds like your 78 MT is sending you down the same rabbit hole my 77 MT did. I spent a whole winter doing all the wood and glass work on the floor and motor box. On your temp a new water pump may help it. My 888 (302 ford) runs about 145ish after thermostat opens. Where are you located at? I dismantled 2 other boats in the building of mine so I have some backup parts. Like I said you are about to do a lot of the same things I went through so if I can help, PM me.

 

[hpcma1]

near southern IL. and yeah i have reglassed the deck and recovered the seats. i still need to do the ones up by the bow, and i have figured out that the speed sensor is shot for the mph gauge. orderng the water pump kit tomorrow along with the new speed sensor, and hoping when drop the lower half, that i find the reverse issue. i took apart the trim sensors to clean but that hasnt helped figure i will break out the ohm meter tomorrow.