alan p Posted October 21, 2012 Share Posted October 21, 2012 Hi All Brought a Merco61 back in 1984 as part of a job lot. Only bench run a couple of times pristine condition. Remained unused and have now dug it out of the archives, unfortunatly all the oil inside has transformed into brown sticky gunk plus the prop driver has no intention of letting go of the crankshaft. It is stripped down to basics but as said, crank is still firmly in as driver will not let go. Knowing there are some very sav vey folks on the forum the question is have any of you suggestions for dissolving said gunk to leave a nice clean engine and bearing.Also the best material for nice thin paper gaskets??? Quote Link to comment Share on other sites More sharing options...
Ady Hayward Posted October 21, 2012 Share Posted October 21, 2012 I have had some success with soaking the parts in petrol over a few days. Gunk or Jizer (Both available from Halfords I believe) do work as they are degreasers. I have heard of Nitromoors being used in very extreme cases, but it is very caustic and needs handling with care. As for paper gaskets I have used the brown paper used in the thick brown envelopes on Merco 49's a long time ago, but card should suffice if it is for the crankcase gaskets. Ady Quote Link to comment Share on other sites More sharing options...
Alan B Posted October 21, 2012 Share Posted October 21, 2012 Hi Alan This one has been asked several times and is in the archives somewhere. Personally I have used Carburettor spray (available at any motor factor) Spray a fair amount into a plastic bag and drop the engine in (parts) and leave overnight to soak. For the outside of the engine fairy Power spray leave for about 30 mins and scrub with an old tooth brush and rinse with water. Other guys will have lots of suggestions eg boling in a pan of water with soap powder. solvents etc. the choice will be yours! KR Al Quote Link to comment Share on other sites More sharing options...
gary davies-jones Posted October 22, 2012 Share Posted October 22, 2012 Acetone is my solution. I soak the engine in the stuff for a few hours. It works a treat and doesn't dissolve anything you don't want it to. After a soak a good scrub with an old toothbrush removes the goo easily. 'O' rings do blow up like balloon though, however leave them to "dry" out and they return to their origional dimmensions. The only fly in the ointment is getting hold of the stuff. the chemists will not sell it in more than 50ml bottles for legal reasons. However if you go to a fiberglass supplier they will sell you as much as you need, usually in 5litre cans for about £8 to£10. As a finnishing trick I use Solvol Autosoll and the old toothbrush. When "dry" and dull another old toothbrush brings out a great shine even in between the cooliPlenty of elbow grease and patience will pay dividends in shine. Paper gaskits? I agree, thick manilla envelopes. P.S. Its safe on Mercos by the way. I've done both my marine 61's this way and they stilll run well (as well as any Merco ever did) and they look really good. Quote Link to comment Share on other sites More sharing options...
Greybeard Posted October 22, 2012 Share Posted October 22, 2012 I've used Nitromoors paint stripper to get the burned on oil off but would try a long soak in a thinner solvent, petrol, alcohol or similar for the propdriver. You may need a sharp rap on the prop shaft to get the crankshaft out, protect the thread with a couple of locked prop nuts before you hit it. Quote Link to comment Share on other sites More sharing options...
FlyinBrian Posted October 22, 2012 Share Posted October 22, 2012 Soak for a few days in glow fuel then clean with a stiff bristle brush. To get the prop driver to release you will need to heat it either with a hot air gun / blow torch (gently) or put the complete crankcase in a hot oven for 20 mins or so. Place the rear of the crancase on a solid wooden block, place a piece of wood on the front of the crankshaft and "tap" it out - this "tap" may need to be quite hard and its better to use softer taps with a big hammer than hard ones with a little hammer. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted October 22, 2012 Share Posted October 22, 2012 Try dunking it in a bottle of coke (any brand) for 24 hours and then brush it off with an old tooth brush. Martyn Quote Link to comment Share on other sites More sharing options...
Solly Posted October 22, 2012 Share Posted October 22, 2012 I would recommend you use a puller to remove the prop driver. Machine Mart do a one for removing battery terminals for a few pounds. I have one and it's very good, - I usually heat the front end up first to soften the deposits before using it. Quote Link to comment Share on other sites More sharing options...
TheFlyingCrust Posted October 22, 2012 Share Posted October 22, 2012 I took a risk on an old motor last year. As the castor deposits can turn into a varnish when heated I had a go with paint stripper! Didn't leave it on the castings for any longer than to get rid of the gunk. Just used an old toothbrush to get it in all the awkward bits. No corrosion from the stripper was evident after (don't forget to wash in warm soapy water after). The motor came up like it had just come out of the box. Paint stripper is quite corrosive and will burn if it comes in contact with skin so wear appropriate protection! I'm not saying I'd recommend this method but it worked for me. Ian Edited By Rentman on 22/10/2012 12:29:30 Quote Link to comment Share on other sites More sharing options...
Braddock, VC Posted October 22, 2012 Share Posted October 22, 2012 By the time you've bought a puller, some stripper and a new set of bearings you won't have much change from £25, I'd spend that on a s/h sc 61 and at least you'll have a half decent, quiet engine that is at least 50% more powerful than the merco, has a far better carb and silencer and is. iirc, more economical. There'll probably be somebody on e-bay who'll bid recklessly for the merco..... Quote Link to comment Share on other sites More sharing options...
David Davis Posted October 22, 2012 Share Posted October 22, 2012 You could try simply heating the engine in an oven! That will probably bake the brown stuff onto the outside of the engine but it will melt the gummed up castor oil inside. Then remove the engine with suitable gloves and squirt a suitable oil into the innards. Quote Link to comment Share on other sites More sharing options...
alan p Posted October 23, 2012 Author Share Posted October 23, 2012 thankyou to everyone Iam trying a selection of suggestions on various parts to see the best results. She who lives indoors was some what puzzled as to why engine parts and not ice was going into the coke!!! Alan Quote Link to comment Share on other sites More sharing options...
Jonnor Posted October 23, 2012 Share Posted October 23, 2012 Soaking it in coke will get rid of years of solidified crap? My god, I'm never going to drink the stuff again................!!!!! Quote Link to comment Share on other sites More sharing options...
Keith Berriman Posted October 23, 2012 Share Posted October 23, 2012 Maybe try Fairy Power Spray from under the kitchen sink Keep a check on its actions and then remove with an old tooth brush Quote Link to comment Share on other sites More sharing options...
gary davies-jones Posted October 24, 2012 Share Posted October 24, 2012 A lot of people are recommending highly corrosive cleaning agents (either acid or alkaline). As a metalurgist, I would shy away from anything corrosive as aluminium is almost unique in that it is highly reactive to both acid and base. Really not a good situation considering the limited ammount of meat and the tolerences involved. Thus my choice of acetone as a substnce capable of disolving the oily residue. By the way the polishing with autosol can then be further enhanced with brasso, BUT ONLY EXTERNALLY, just in case any body has a go at the inside. "Well thats what I think anyway." Gary Quote Link to comment Share on other sites More sharing options...
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