Jon H Posted March 4, 2023 Share Posted March 4, 2023 9 hours ago, Jonathan W said: I wouldn't spend any money on bearings until you have stripped it all apart and checked the condition of the cylinder bore. yep this is a very good idea. Quote Link to comment Share on other sites More sharing options...
Doug Campbell Posted March 4, 2023 Share Posted March 4, 2023 Duraglo is a brilliant fuel. Ran it for years with no corrosion, engine wear minimal. Jon let’s his emotions cloud his judgement at times 1 1 Quote Link to comment Share on other sites More sharing options...
KenC Posted March 4, 2023 Author Share Posted March 4, 2023 Thanks for the tip on the fuel, I need to get some after I have rebuilt this engine . With a bit of luck this incoming horrid stuff is the last shake of the winter. Quote Link to comment Share on other sites More sharing options...
Andy Stephenson Posted March 4, 2023 Share Posted March 4, 2023 If this was my engine, before doing anything else or spending any money on it, I would take the cylinder head off and check the bore for flakey plating. This was a particular problem with the OS 46FX. From new, mine needed two replacement pistons and liners before the problem was solved. 1 Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted March 4, 2023 Share Posted March 4, 2023 37 minutes ago, Andy Stephenson said: If this was my engine, before doing anything else or spending any money on it, I would take the cylinder head off and check the bore for flakey plating. This was a particular problem with the OS 46FX. From new, mine needed two replacement pistons and liners before the problem was solved. "De chroming" a common problem with OS, Magnum and Thunder tiger, and Irvine, OS and Irvine it flaked off around the exhaust, the others mostly because of using 'bad' fuel and running them in on the bench,,, Quote Link to comment Share on other sites More sharing options...
Andy Stephenson Posted March 4, 2023 Share Posted March 4, 2023 (edited) 32 minutes ago, Paul De Tourtoulon said: "De chroming" a common problem with OS, Magnum and Thunder tiger, and Irvine, OS and Irvine it flaked off around the exhaust, the others mostly because of using 'bad' fuel and running them in on the bench,,, Yes but OS insisted on using the inferior nickel instead of chrome because the process is cheaper and easier to do. My 46 FX is the only engine it has happened to me with. PS I have to add it also happened with my OS61RF. Edited March 4, 2023 by Andy Stephenson Quote Link to comment Share on other sites More sharing options...
KenC Posted March 4, 2023 Author Share Posted March 4, 2023 Ok gents, update I removed the rear plate and had a peek inside, not too bad for my untrained eye. To remove bearings I need the head off and when I tried the screws ( key head) are so stiff as to be easier to damage than resolve any issues. I have cleaned her as best as can and mopped any water from the freeing, as best as can. I almost think the cost of a piston, liner, bearings, possibly head bolts ( 6 ) etc etc is going to challenge the value of a new unit. I feel I might swap the plug remount ( new bolts needed for the engine mount) and run it to see if it can manage as is. If it is to be replaced , what is the consensus on a replacement .... another OS 46AX £140 or something else ? Quote Link to comment Share on other sites More sharing options...
Keith Berriman Posted March 4, 2023 Share Posted March 4, 2023 How about the Force 46 around £100 Kings Lynn models Quote Link to comment Share on other sites More sharing options...
Jon H Posted March 4, 2023 Share Posted March 4, 2023 7 hours ago, Doug Campbell said: Duraglo is a brilliant fuel. Ran it for years with no corrosion, engine wear minimal. Jon let’s his emotions cloud his judgement at times Err, no, i just know more about it than an end user. its kinda my job. Duraglo is awful, castor is awful. By every possible measure synthetic oils are superior. Even model diesel engine manufacturers are no longer recommending castor. Its day is well and truly done, so lets just move on. I honestly i cannot begin to fathom why this simple fact is resisted every time it is raised. My only emotion is frustration at the complete inability of old dogs to learn anything at all, let alone a new trick. its not the 1980's any more, things have moved on. Ken, do you have a photo you can post of the innards? Might give some insight into the condition. Before considering a replacement you need to get this one apart. The head bolts should come undone without too much trouble but you do need a decent allen key of the right size. If you are using a screw driver bit it can help to fit the bit in the bolt and give it a whack with a hammer. I do this quite often at work with engines that have been together for years and do not want to come apart. The liner plague discussed is only a maybe and although a relatively common issue its not guaranteed your engine is damaged. It is worth knowing though. If its already gone you might as well just run the engine until it dies as i dont think you can get spares any more anyway. If its alright, you can still check the bearings and replace if needed giving you a good engine and peace of mind that its in good condition. All is not lost, dont give up on it just yet. On the plating, i think OS used electroless plating on their liners and it was more the process rather than the material that caused the trouble. Not totally sure but that was my understanding. Quote Link to comment Share on other sites More sharing options...
Kevin Fairgrieve Posted March 4, 2023 Share Posted March 4, 2023 A knackered liner will look like this. This was from an OS46FX that I rebuilt. When spares were still available. Quote Link to comment Share on other sites More sharing options...
Jon H Posted March 4, 2023 Share Posted March 4, 2023 16 minutes ago, Kevin Fairgrieve said: A knackered liner will look like this. This was from an OS46FX that I rebuilt. When spares were still available. Good lord. That has to be worst one i have ever seen. Its almost all brass! I rebuilt a few with ASP chrome brass liners and they went well after repairs. Shame the old nickel plating cant be honed off and the thing re chromed in the garden. There are videos online on how to do it. Might be a fun project Quote Link to comment Share on other sites More sharing options...
Kevin Fairgrieve Posted March 4, 2023 Share Posted March 4, 2023 3 minutes ago, Jon - Laser Engines said: Good lord. That has to be worst one i have ever seen. Its almost all brass! I rebuilt a few with ASP chrome brass liners and they went well after repairs. Shame the old nickel plating cant be honed off and the thing re chromed in the garden. There are videos online on how to do it. Might be a fun project Yes, this one was rebuilt using ASP spare parts. Turned out to be a great engine. Quote Link to comment Share on other sites More sharing options...
Jon H Posted March 4, 2023 Share Posted March 4, 2023 11 minutes ago, Kevin Fairgrieve said: Yes, this one was rebuilt using ASP spare parts. Turned out to be a great engine. Ironic that the clone ASP parts made with chrome were better than the OEM parts in nickel. I think i read they changed from chrome due to its toxicity during manufacture, and environmental regs or something? I might have dreamt it, but for some reason it rings a bell. Quote Link to comment Share on other sites More sharing options...
KenC Posted March 4, 2023 Author Share Posted March 4, 2023 Here is a view with the rear plate off Quote Link to comment Share on other sites More sharing options...
Jon H Posted March 4, 2023 Share Posted March 4, 2023 6 minutes ago, KenC said: Here is a view with the rear plate off Its done. New bearings required. Quote Link to comment Share on other sites More sharing options...
KenC Posted March 4, 2023 Author Share Posted March 4, 2023 Damn ! Not what I was hoping to hear , I took the plug out and turned it over and it is very smooth . Quote Link to comment Share on other sites More sharing options...
Jonathan W Posted March 4, 2023 Share Posted March 4, 2023 Well, I've seen far worse. If they feel smooth, I think the engine would run OK with those bearings, but they would need replacing in the near future. The main thing is to get the head off and look at the cylinder bore. Have you tried some heat? A hot air heat gun is a handy thing. Get the cylinder fins and head nice and hot, then give it another go with a good fitting hexagon key. Helps to hold the engine wearing oven gloves or similar. Whereabouts are you? Perhaps another forum member more confident in these things could assist you personally. Quote Link to comment Share on other sites More sharing options...
KenC Posted March 4, 2023 Author Share Posted March 4, 2023 (edited) Tried with a second set of allen keys and they are going to damage the head screws by slipping. What do you use ? I am between Maidstone and Cranbrook in Kent Edited March 4, 2023 by KenC Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted March 4, 2023 Share Posted March 4, 2023 1 minute ago, KenC said: Tried with a second set of allen keys and they are going to damage the head screws by slipping. What do you use ? If they round off, torx bits can rescue you, tap them in first. Quote Link to comment Share on other sites More sharing options...
Jonathan W Posted March 4, 2023 Share Posted March 4, 2023 (edited) Do you have the correct size key? The screws will be metric, not imperial. Probably 2.5mm key needed. Make sure there is no debris inside the screw heads, so the key can engage to the full depth. Can also try with a small punch and light hammer to carefully apply a shock to the screw heads, but don't be too brutal! Edited March 4, 2023 by Jonathan W spelling Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted March 4, 2023 Share Posted March 4, 2023 https://www.amazon.co.uk/s?k=tork+bit&adgrpid=1181975898969545&hvadid=73873712643227&hvbmt=be&hvdev=c&hvlocphy=4076&hvnetw=o&hvqmt=e&hvtargid=kwd-73873631948997%3Aloc-188&hydadcr=5054_2345135&tag=mh0a9-21&ref=pd_sl_i2ivxttym_e Quote Link to comment Share on other sites More sharing options...
Jonathan W Posted March 4, 2023 Share Posted March 4, 2023 It's an easy job if you have the right gear and technique. I'm happy to help, but not knowing where you are located.... Quote Link to comment Share on other sites More sharing options...
Don Fry Posted March 4, 2023 Share Posted March 4, 2023 3 minutes ago, Jonathan W said: Do you have the correct size key? The screws will be metric, not imperial. Probably 2.5mm key needed. Make sure there is no debris inside the screw heads, so the key can egage to the full depth. Can also try with a small punch and light hammer to carefully apply a shock to the screw heads, but don't be too brutal! Do OS engines use metric. I seem to recall a lot of UNF. Ancient brain cell, soaked in whisky, but it says UNF. Quote Link to comment Share on other sites More sharing options...
Jonathan W Posted March 4, 2023 Share Posted March 4, 2023 Hi Don, They use UNF for the crankshaft thread. The small screws holding the engine case parts together are always metric on the modern OS engines. 1 Quote Link to comment Share on other sites More sharing options...
Jonathan W Posted March 4, 2023 Share Posted March 4, 2023 17 minutes ago, KenC said: I am between Maidstone and Cranbrook in Kent Ah, Kent not very near to Northamptonshire unfortunately! If you get really stuck, feel free to post me the engine and I'm sure I could sort it for you. Quote Link to comment Share on other sites More sharing options...
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