Andy J Posted July 7, 2021 Author Share Posted July 7, 2021 20 hours ago, Engine Doctor said: My previous post should read "There should be a thrust washer between the prop driver and case" not an ordinary washer. Sorry got the builders in and was distracted. Engine Doctor can you suggest a source for thrust washers please. Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted July 7, 2021 Share Posted July 7, 2021 Sorry , simply answer is no. I usually make one if I get stuck from some thin steel sheet or grind and polish a washer to fit. If your engine has a lot of end float then an ordinary washer, provided it's polished will do the job. With a thrust washer fitted there should still be between 5 and 10 thou end float on crank shaft so provided it doesn't lock up when prop is fully tightened and ghee is some end float your engine will be OK. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted July 8, 2021 Share Posted July 8, 2021 Just happened to spot that Modelfixings are listing shim washers in various sizes...https://www.modelfixings.co.uk/shim_washers.htm Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted July 8, 2021 Share Posted July 8, 2021 Cool, model fixings seem good but sometimes you have to think outside the "box"...wine comes in boxes, does beer, probably not. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted July 8, 2021 Share Posted July 8, 2021 Those old ringless motors were always run on castor fuel which would soon build up a compression seal. Waste of time trying that with synthetic. When I did an (awful) lot of flying my motors were cleaned internally and re bearinged every six weeks, including ABC ones which needed the piston lapping, but a couple of tanks of castor later they were as good as new. Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted July 8, 2021 Share Posted July 8, 2021 (edited) Yes, and a few drops of MT after run oil distributed around inside the engine to keep any corrosion etching at bay during lay up over the winter. I used to fly every day back in the day, apart from in gales, off shore winds and rain. Still got my original magnum gp40 that will be fitted to an rc'd largish free flight conversion when it's time comes. Wish I lived "back home".... Why no flying in off shore winds ? I did once, never again ! I nearly crashed the plane ! I should have known better as I had watched the mist falling down the hills rolling and rolling. Just because it wasn't misty that day did I think the air was not rolling down off the hills ? Lesson learnt quite quickly I can tell you. As said I only strip and clean engines to make sure the lubrication channel for the crank is clear. Not all engines have this lubrication channel, the 35 merco has, as has the gp40. I do not clean the piston or cylinder, to keep the castor "seal"... Edited July 8, 2021 by Rich Griff Quote Link to comment Share on other sites More sharing options...
Andy J Posted July 9, 2021 Author Share Posted July 9, 2021 On 08/07/2021 at 11:23, Martin Harris - Moderator said: Just happened to spot that Modelfixings are listing shim washers in various sizes...https://www.modelfixings.co.uk/shim_washers.htm Sorry on my ignorance but is a shim washer the same as a thrust washer? Thought a thrust washer is slightly curvature to cause a continual pressure on the shaft. Quote Link to comment Share on other sites More sharing options...
Andy J Posted July 18, 2021 Author Share Posted July 18, 2021 Finally managed to get the engine to run but I find the inner cylinder lining is turning thus closing off the exhaust. Believe the issue is caused by the lack of a gasket between the lining and the cylinder head as the sleeve fits into a recess cut into the head. Given the gasket is only a few mm's wide think this is going to be difficult to cut so now need to find a 1" fiber gasket from a plumbers outlet or similar. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted July 18, 2021 Share Posted July 18, 2021 It's over 40 years since I had dealings with a Merco 35 but most 2 strokes have a method of positively locating the sleeve - often a small roll pin locating a slot in the top flange. Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted July 19, 2021 Share Posted July 19, 2021 (edited) The head gasket should I believe be aluminium. You can easily cut one from a piece of litho plate. A fiber washer will be too thick and can cause the head to warp if overtightened. The litho plate will need to be annealed first. Then use the liner to scribe the I/D & O/D . Cut the inner out with a scalpel and the outer with some sharp scissors. This will also sealthe head properly increasing compression. If you don't have any litho plate use aluminium from a beer can or similar. Martin. The Merco cylinder didn't have a locating pin as the cylinder was a tight fit in the case , usually needed high heat to remove it especially when castor oil had glued it in place and was clamped in position by the head. Edited July 19, 2021 by Engine Doctor Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted July 19, 2021 Share Posted July 19, 2021 I used some dividers from a geometry set to scribe and then cut through, wine comes in boxes ..... Make sure there is a gap between head and c/case when gasket ring is fitted and seated and the head is fitted with the screws tight, diagonally. Don't strip the head screw threads. Is the Conrod bent ? Quote Link to comment Share on other sites More sharing options...
Andy J Posted July 19, 2021 Author Share Posted July 19, 2021 Engine Doctor is it the inner gasket that is made from litho or the outer? Have plenty of litho in the workshop so could always try making both as noticed several screw holes on the outer gasket have already torn. Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted July 19, 2021 Share Posted July 19, 2021 (edited) Goto mecoa and see the merco parts section exploded view and if the gaskets etc. are listed... As far as I know, the 35 aero only has the gasket that is recessed into the head. I will check the parts list in my ripmax old catalogue but not untill this evening to try and help. I have sourced another 35 carb complete with good jet assembly, the spray bar etc. which should be with me by the weekend, happy days... Once test run it will be going into a period RC plane, possibly a tauri or super tourism... The 29 when test run will be going into an "enlarged" aspis RC, possibly with aelerons... Lovely day again today but since I am not a dog or English I will be busy in the shade ! Edited July 19, 2021 by Rich Griff Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted July 19, 2021 Share Posted July 19, 2021 Toauri not tourism, stupid phone... Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted July 19, 2021 Share Posted July 19, 2021 The head gasket is a fiber, I can supply ones for both 29 and 35 Quote Link to comment Share on other sites More sharing options...
Andy J Posted July 19, 2021 Author Share Posted July 19, 2021 PM sent Jeff. Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted July 19, 2021 Share Posted July 19, 2021 (edited) 20210719_172313.heic I'm selling these,2x35 and 29 anyone interested pm me please Edited July 19, 2021 by jeff2wings wrong pic file Quote Link to comment Share on other sites More sharing options...
Andy J Posted July 27, 2021 Author Share Posted July 27, 2021 On 19/07/2021 at 13:22, jeff2wings said: The head gasket is a fiber, I can supply ones for both 29 and 35 Thanks very much Jeff, more than generous as to the number of gaskets provided. Not sure I will use this amount so happy to pass one on if anyone else needs one for a Merco 35. Quote Link to comment Share on other sites More sharing options...
Andy J Posted August 4, 2021 Author Share Posted August 4, 2021 Gave the engine a short run yesterday and already the compression is a lot better after fitting the new gasket so thanks again Jeff. Yet to run my Merco 61 but that is next on the list of jobs to do. Quote Link to comment Share on other sites More sharing options...
Philip Williams 2 Posted March 11, 2023 Share Posted March 11, 2023 Hi Andy J, I am in the process of stripping and cleaning a very old '35, a 'red head' exactly like the one I bought from 308 Holloway Road in April / May 1961. Yes, I did regret selling it many years ago, however, this one was gummed solid both inside and out. I gave it a 20 minute boiling in a good litre of water dosed with about a tablespoon of the wifes 'non bio' wash powder, which took off all of the outside hardened castor oil crud. It did this without discolouring the finish on the engine at all and all the screws came out without any fight too. I too used a carefully applied heat gun to free up the Head and Backplate, together with the Cylinder Liner and finally the Piston and Con Rod. The Carb' (or should I say 'barrel throttle', - this was the first British production R/C engine after all) came out easily. So, yes Andy if you still have those fibre head gaskets, I would much like a couple please. Contact me via the moderator I think, Phil W. Quote Link to comment Share on other sites More sharing options...
Andy J Posted March 11, 2023 Author Share Posted March 11, 2023 Have no idea now as to their location Philip. In the middle of decorating in time for a new carpet to be fitted so being allowed to play in the shed is currently off limits. Should be back to normal ops by the end of the week so will go in search of the items. Quote Link to comment Share on other sites More sharing options...
Philip Williams 2 Posted March 12, 2023 Share Posted March 12, 2023 Cheers Andy, I'm not busting a spring to get the engine back together, I am in the process of making a 'Brian Winch' design bicarbonate of soda blaster to assist with some of the more reluctant surfaces. Thanks a bunch for your help, and remember, any costs are my costs not yours. Phil W. Quote Link to comment Share on other sites More sharing options...
Robert Cracknell Posted March 13, 2023 Share Posted March 13, 2023 Phil, I am intrigued and interested in the Brian Winch bicarbonate of soda blaster. Where did you get the details from? I have one of the Badger airbrush sized grit blasters and have used it with table salt (the grit supplied and fine sand is too aggressive). The table salt cleans effectively but leaves a dull finish. I don't know if you can buy Guyson beads small enough for this gun but they leave a very good finish. Quote Link to comment Share on other sites More sharing options...
Andy J Posted March 15, 2023 Author Share Posted March 15, 2023 Philip, found a couple of gaskets, so if you ping me your address via a PM I will put them in the post. Quote Link to comment Share on other sites More sharing options...
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