85 hp needs wiring etc after long non-usage

Dane Way · Aug 3, 2004

I must say that I am one of the silent majority. Not one to speak up about much, especially online, but you folks seem to be kind to guys like me that are willing to say they don't know much about outboard motors but are willing to at least try to learn. So here goes. I have a 1976 Merc 8500 serial # 4370530. It has been sitting outside for about 12 years as far as I can determine. I am slowly trying to do what I can in getting it back into running condition, but I don't have much outboard experience. First off, just by taking off the cowling I find I need to replace most of the wiring. Almost all of the wiring has corroded ends or flaking insulation. I have searched the internet and am not coming up with anywhere that I can purchase the wiring harnesses aside from the wiring harness assembly from the controls to the motor. I have on order a replacement interior wiring harness, however that is only going to take care of a small portion of the wiring. Can anyone tell me what gauge wire I need to get, and from where, that I can use to rewire the rest of the motor? I know that I need marine quality primary wire that has been specially tinned. I have been to the mercruiserpart.com site and found a couple of wiring harness assemblies that are no longer available. Does anyone have any other place I might contact about the wiring? Also I need advice on what you think about trying to follow the wiring to the stator and trigger assemblies and when I find good wire snip it and patch in with new? Or with the long lay off of the motor should I just purchase new assemblies and not worry about it because they may test bad even with the new wiring? Haven't done any tests yet. I know this is picky, but I would like to keep the wiring the same color as what the switchbox is calling for, yet I can't find any of the primary wire with stripes, ie. white/black stripe, green/black stripe, blue/white etc. If anyone can point me in the direction of somewhere I can purchase these I would greatly appreciate it. I want to take care of the electical side of the motor before starting with the mechanical. I am sure turning the switch with as many bare and crusty wires could burn up some component that might actually stiil be ok. Once I get the wiring taken care off, what should be my next move? Comprehension check, new plugs, clean carbs, water pump and impeller kits - anything else? I do have a manual on order. Again, thanks for all the help I am sure will come my way. Dane

Chucky P · Aug 3, 2004

Re: 85 hp needs wiring etc after long non-usage

I just replaced these parts you are talking about.The stater (thats what the wires are going to on the top )is $150.00 my wires were rotted all the into this. the bottom harness is $130.00. You can get them from Reynolds in TN. PH.865 882 9623. BUT I DID THE SAME THING YOU ARE FIXING TO DO AND HAD MORE TROUBLE YOU CAN EMAIL ME AT cepy@knology.net might save you alot!

Merc805 · Aug 3, 2004

Re: 85 hp needs wiring etc after long non-usage

You don't need "Marine tinned" wiring for any other reason than they will be more corrosion resistant. You can use similar amp/gauge wires as found in the automotive industry, Yes.. rather than replace stator,trigger and other very expensive parts, you can carefully cut the wires back and crimp or solder and re-insulate. Clams Canino has a good technique for this. Do a search of his posts. As far as colour, I agree .. keep them the same for the next owner.. If you can get them. If you can get the leg off (Not Stainless), Do the water pump.I would do that FIRST before you spend anything. If it is seized, you are in for a big fight.

Barnacle_Bill · Aug 3, 2004

Re: 85 hp needs wiring etc after long non-usage

If it has been sitting up for that long, I think I would be sure the pistons are not froze up first.

Dane Way · Aug 4, 2004

Re: 85 hp needs wiring etc after long non-usage

Thanks for the info so far. Chucky - I will email you later in the day. Lots on my plate right now. Castaway - I do want to find out about the water pump. Have read horror stories about stuck lower units. I will do a search of Clams and his technique(s) for wiring. Bill - I sprayed oil in each cylinder and spun the flywheel several times. Actually took a flashlight and peeked in the top 3 while turning the flywheel and things were going up and down. I should be receiving the manual in the next couple of days and will report back when I know more. Thanks for the suggestions. Dane

Chris1956 · Aug 4, 2004

Re: 85 hp needs wiring etc after long non-usage

1Danish, The Engine harness is available for ~$85 from www.surplusunlimited.com. It includes all the wiring from the plug to the switchbox and stator. If you need sparkplug wires go to www.oldmercs.com, where they are $5.95 each. Ypu can reuse the gboots and spring connectors. Use a piece of 14 ga. marine wire for the switchbox to ignition coil lead. I have not found any great discounts on impeller kits. Spark Plugs are cheapest at any auto store.

Dane Way · Aug 6, 2004

Re: 85 hp needs wiring etc after long non-usage

Thanks Chris, I have an internal engine harness on its way. I did also find a site that advertises that it has a couple of the other internal wiring harnesses. Will get those ordered today. Hope they are in stock. I do have another question. When I redo the water pump and impeller do I need a lower unit seal kit? I know that sometimes one repair leads to another. Just wondering. No one that I have read has mentioned needing or using a seal kit when working on their impeller or water pump. Maybe it is just a given and I am so new to working on outboards that I haven't learned that yet? Thanks for all the help. Dane

Chris1956 · Aug 6, 2004

Re: 85 hp needs wiring etc after long non-usage

1danish, The lower unit is sealed by two propshaft seals, two driveshaft seals (in the waterpump base), shift shaft seal and waterpump o-ring and gasket. I have found that the propshaft and shiftshaft seals do not usually go bad. The good news is that the other seals, gasket and o-rings are easy to install. If you suspect a leak, buy an aftermarket waterpump base kit. The driveshaft seals are already installed in the waterpump base, and although they are available seperately(dealer only), the price differential is small. I do not remember if the impeller comes with the waterpump base kit. Anyway, when you replace the impeller, replace the waterpump base gasket and o-ring. You need to match the o-ring and gaskets to the pump you have, since these kits will have several o-rings and gaskets. Also, the kits come with gaskets for the fill and drain plugs of the gearcase.

Dane Way · Aug 7, 2004

Re: 85 hp needs wiring etc after long non-usage

Thanks Chris, As luck would have it I ordered some parts - they came - but the impeller/water pump kit they sent was for a Johnson/Evenrude 85 horse. Said so right on the package and the part numbers didn't even come close to the ones I ordered. So will send that back and hopefully get the correct parts. I do appreciate everyone that has put in their advice. I am learning a lot and so far I don't think I have irreparably broken anything. Knock on wood. Can anyone tell me if my motor has a thermostat or a water pressure relief valve assembly? I received a manual today, Seloc, and in almost every exploded diagram of the powerhead they show a thermostat and a water pressure relief valve assembly. I have looked at my motor and I guess I don't know where to find them. Unless they are behind or beneath something and I haven't looked in the right places. Also there is a tube that comes out of the top of the powerhead just under the flywheel and goes behind the switchbox and then enters the lower unit. It has a crack right at the uppermost part where it bends after coming out of the motor. What is this tube and what does it do? It doesn't seem to be made out of rubber tubing such as the fuel lines. Would like to know so I can order another one or if doesn't need to take high pressures etc. maybe I can substitute some other kind of tubing? Again, thanks for the help. Please don't shoot me for asking stupid questions, but you guys are great and I've never done this before. I would rather be safe than sorry. Dane

Chris1956 · Aug 9, 2004

Re: 85 hp needs wiring etc after long non-usage

1danish, Those motors do not have thermostats or water pressure relief valves. They ate open circuit, raw water cooled. The manual is either wrong, or you are looking at a V6 motor. I can not tell what that tube is for from your description. On my 1977 inline 6 there is a small rubber tube that runs from the bottom main bearing to the top main bearing. Using a couple of one-way valves, excess oil is forced to the top the the motor to lubricate the top main bearing.

Dane Way · Aug 11, 2004

Re: 85 hp needs wiring etc after long non-usage

Thanks for the imput Chris, The manual is a bit sketchy in many respects. Probably makes all kinds of sense to someone that has worked on outboards before, but takes a bit of trial and error for the neophyte wrench to understand what it means. I know it is tough to cover the many models in a given hp range so maybe it is as good as it gets and I have to get smarter. I will assume the tube is for oil, however it doesn't have any kind of clamp that holds it on - slides on over a serrated fitting but looks as if any kind of pressure could pop it off without much effort. I installed new impeller and water pump housing. Actually went fairly smoothly until trying to put the lower unit back on the motor. Very difficult to get the water pump and water tube lined up and push it all together by yourself. Took me about an hour of futile shoving before my wife came out and helped me line it up. Still then it didn't want to pop back together. Had to pull it all together by tightening bolts in rotation. A bit at a time until it went back in place. Hope that is a proper procedure. Did get forward, neutral, and reverse by shifting and rotating the flywheel. Haven't finished the wiring so don't know if it will pee and shift into the correct gear when in the water, but I am hopeful. Just got word that the company that I thought still sold wiring harnesses doesn't, so I think I will make my own. Been wanting to have the same colored wire from the switchbox to coils etc. as the manufacture calls for, but can't find any wire with stripes. Might make a quick search of automotive wire - I know it should be marine tinned AGW wiring but can only get it in solid colors. Does anyone know where I could purchase a flywheel puller? To all of you that have responded to my posts, I greatly thank you. You all have helped beyond what words can describe. I am sure I will have more questions as I work my way through cleaning the carbs and testing procedures for the stator and trigger. Hope I don't come across as too much of a fool. I am learning a great deal and who knows, maybe I might be able to post a reply to somebody else's question in the future and put them on the right track. Thanks again for all the helpful advice.

Chris1956 · Aug 12, 2004

Re: 85 hp needs wiring etc after long non-usage

1danish, That motor has a two piece flywheeel. You can use a harmonic balancer puller with fine thread 5/16" bolts. However, I just remove the flywheel nut, reinstall it upside down, even with the top thread, apply some presure to pry the flywheel up, and smack the nut gently with a hammer. It will usually pop off w/o much issue.

MercMark · Aug 12, 2004

Re: 85 hp needs wiring etc after long non-usage

I just tore apart my 850. You're going to find that universal pullers won't work on your flywheel. Mercury had a bad habit of making custom tools. I had to buy their flywheel puller which threads in around the nut in the flywheel. There are no holes on these merc flywhells for universal pullers. I paid about $100 Canadian for mine. They're available through quick silver. I tried old fashioned methods that involve tappign the crank with a hammer and none worked, although I was pretty shy about using a lot of force. You get the puller give it a couple of cranks and violla. Heck, I'll sell you mine for $50. Mail me a cheque with your return address. My serial number was 7033755. Check and make sure they're the same. I can post a pic of my flywheel with a verier in the hole to see if they're even close.

Dane Way · Sep 2, 2004

Re: 85 hp needs wiring etc after long non-usage

Hi Guys, Wanted to give an update because everyone has been really helpful and I think I am getting close. Can't start smoking the victory cigar just yet, but close enough that I am now starting to think that it is a possibility. With a project like this - motor sitting out in the elements for 12 or so years I am sure I should expect two steps forward and one back for a while. I am hoping that I am getting closer to three or four steps forward for everyone back. Anyways.... Here is what I have been able to accomplish so far. Replaced water pump housing and impeller. See above post. Because the wiring was worse than I orginally thought -insulation flaking and corroded from one end of wires to the other, (on all but 3 wires) I ended up replacing both the trigger and the stator. Went ahead and replaced the "mercury "switch." Replaced every ground wire I could find. Replaced the internal harness assembly that connects to the harness assembly from the key/control box. Had to make the ground wire harnesses from each coil because they are no longer available to purchase. Also replaced the coil to switchbox wires. Couldn't get the green with proper stripe for this, but with a few daubs of red fingernail polish, black liquid plastic, white-out was able to at least make it look like I tried to keep to the factory specs. Bought a new deep cycle and starter battery. New gas tank, hose,fittings, gas and oil. When I got that all finished I couldn't help myself. I had to give it a try. Hooked up the new battery and fuel hose, pumped until the bulb got hard - gas running from bottom carb. Clamped on the muffs, jumped in the front seat, pulled the fast idle handle forward, held down the choke button and turned the key. Click - all I got was one click. Wouldn't make another sound. My heart sunk and I felt a bit depressed, but went back to problem solving. Came back to this forum and read more posts. Slept on it. The next time I had a chance to get back to the motor I cleaned and polished the main positive and ground wires from the harness that connect to the battery. Primed the bulb again, turned the key and it ran!! It turned over about 4 times and started running!!! WHOO HOOO!! Old plugs and wires to boot!! Not great mind you but it was running. Quickly looked for pee stream - none. Immediately shut down the motor and cleaned out the hose, disconnected it from the head where it comes out between cylinders 2 and 3 looked in and couldn't see any obstructions. I don't have any compressed air so I tried to force water in the hole hoping to dislodge anything that may be clogging up the system. Please don't laugh but I used a turkey baster. Fit perfectly in the hole and I could force water in and out. Must have done a little good because I when I started it again it peed a very small spittle. Not good enough to keep it running for more than 15 - 20 seconds but at least enough to make me think that the impeller was at least turning. Still have to get it better. I still want to rebuild the carbs and do have a new fuel pump diaphram. Have new spark plugs. Does anyone have any suggestions about not getting a good tell tale stream? If I can't get any better volume I will probably pull the lower unit again to see if I put something together incorrectly. I don't know if I will be able to tell but can't run the motor like it is. Any advice would be appreciated. Also - How tough is it to get the carbs off to overhaul? I haven't really looked hard at them, but that bottom carb looks like a bear because it is mostly even with or below the bottom cowling. I have big hands and it looks like a small space? Will give it a go however because I can tell this motor really wants to run. Thanks for all of the help so far. This forum is a wealth of knowledge. If anyone has any ideas of how I should proceed from here I would grealtly appreciate it. - Dane

Chucky P · Sep 3, 2004

Re: 85 hp needs wiring etc after long non-usage

tHIS IS CHUCK GOOD TO HERE IT STARTED. CARBS ARNT HARD TO REBUILD.YOU DID TAKE COMP TEST OK . IT MIGHT BENA GOOD IDEA TO RUN EXTRA OIL IN GAS FOR A MAYBE 1OR 2 TANKS. JUST A IDEA I WOULD AND IT WON'T HURT. GOOD LUCK CHUCK

Dane Way · Sep 6, 2004

Re: 85 hp needs wiring etc after long non-usage

Thanks for the suggestions Chuck. I went ahead and cleaned/rebuilt the carbs and added new seats and valves. Wasn't as hard as I thought, although a couple of those lower bolts holding the crazy air horn jobby were a bit time consuming to get out and back in. Everything back together. I still need to overhaul the fuel pump. I am able to get the motor to start and run nicely at fast idle with the fast idle lever up just a tad. After adjusting both carb's idle screws I am able to get it to idle with the lever all the way down - but only for about a minute then the motor will die. When I go to restart it acts like it needs extra fuel. So I am thinking (hoping) that the old fuel pump diaphram is good enough to keep the motor going at fast idle but not at slow. Will let everyone know after I get that finished as to if that helps. I went ahead and took the lower unit back off to have a look see at the waterpump etc. because of the lack of pee stream. When I pulled the unit off the entire copper water tube came with it. At first I bad thoughts, however, the tube looked ok. Neither end was mashed, squished or bent. It wasn't kinked, crushed or worn through anywhere. I was able to push it back up into its proper place then I reattached the lower unit. Pees a good steady stream now. I am much happier. Just need to work on getting it to idle properly. I haven't checked the timing yet. After swapping all of the electrical parts I don't think it would hurt to make sure. Will try to get that done sometime this week. My book says that it should be timed to 27 degrees. Anyone have any other ideas about that? I have read in other strands to decrease that a couple of degrees because of the lower grade fuel we get nowadays. Just wondering what anyone thinks. Thanks - Dane

Chucky P · Sep 6, 2004

Re: 85 hp needs wiring etc after long non-usage

Sounds Good. You can set up your idle by adjusting idle stop. Set the idle stop after she warms up.Use the Idle lever till it warms up.I got to take mine out to Booms day. They have a large Fire works display on the river,and across the Bridge.I try to go to it every year but thought We would miss it this year with boat down. Once you get the boat on the water,You might have to open the needle screws to richen up a little to stop bogging Just 1/8 turn each carb at a time(counter clock)GOOD TO HEAR FROM YA Chuck :

Clams Canino · Sep 6, 2004

Re: 85 hp needs wiring etc after long non-usage

ALSO - Use a can of Mercury Power Tune as directed - twice even. Sticky rings are common in those things. -W

85 hp needs wiring etc after long non-usage

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