J D 8 Posted September 30, 2021 Share Posted September 30, 2021 I went flying the other day with my old ARC Jupiter. A good aircraft to have a thrash about when conditions are a bit rough. It is my most flown model with its original RED Irvine 46 having reliably pulled it around the sky for years. At the field when starting it suddenly went stiff, was down on power and would not tick over even when trimmed up some. Turning it by hand one could feel it was stiff and a bit graunchy. Thought a bearing was on the way out, on this 20 year plus engine so packed up. Today I pulled the motor and stripped it to find that the red paint inside the engine fuel/air passages had peeled and was gumming thing up. Bit daft to leave paint inside the casing I recon. You can see a bit beside the engine in the pic and perhaps some more of the remains inside I am scraping out with a bit old credit card. Anyone come across this before ? As piston, liner and compression are still good will renew bearings and hope to be good to go again 1 Quote Link to comment Share on other sites More sharing options...
Jon H Posted September 30, 2021 Share Posted September 30, 2021 these were powder coated i believe and that should be quite resistant. That said, the poor thing looks a little toasted so that could be contributory? Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted September 30, 2021 Share Posted September 30, 2021 As a matter of interest, may I ask what fuel have you been using please ? Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted September 30, 2021 Share Posted September 30, 2021 Looks like the dreaded Castor to me ? Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted September 30, 2021 Share Posted September 30, 2021 hello JD 8, funny for this to happen after 20 years of use......maybe it is something else. ken anderson...ne..1..what is it dept. Quote Link to comment Share on other sites More sharing options...
Brian Sweeting 1 Posted September 30, 2021 Share Posted September 30, 2021 Looks like a fuel residue to me. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted September 30, 2021 Share Posted September 30, 2021 powder coating on the inside? sure that's what it is? 2 hours ago, J D 8 said: At the field when starting it suddenly went stiff over-primed & bent rod? Quote Link to comment Share on other sites More sharing options...
kevin b Posted September 30, 2021 Share Posted September 30, 2021 Looks more like the carb has ingested something. Good luck with cleaning the outside. My ultrasonic cleaner probably wouldn't even touch it !!! Quote Link to comment Share on other sites More sharing options...
J D 8 Posted September 30, 2021 Author Share Posted September 30, 2021 Engine has been in the Jupiter for twenty years and used as winter hack for many years [ two aileron connections, one wing bolt and away to go ] Fuel ? Well you name it its probably had it. I moved away from castor years ago but it will have seen plenty in younger days. Head is very coated but the casing is still clean and tidy . Nothing is bent or broken, rear bearing is a bit worn but still spins now the gungy old peeling coating has been removed and I am sure that what it is/was as have been able to scrape away more from the inner parts of the casing. I guess the old coating decided to give up and turn to glue. I wondered if anyone else had seen this ? Not complaining, this engine has done me very well and will go on again once cleaned up with new bearings. 2 Quote Link to comment Share on other sites More sharing options...
Christopher Wolfe Posted October 1, 2021 Share Posted October 1, 2021 G'day J D 8 Saito have been known to even paint the inside of some combustion chambers. Saito FA-100T Vert strange indeed ! Chris Quote Link to comment Share on other sites More sharing options...
Nigel R Posted October 1, 2021 Share Posted October 1, 2021 Barking! Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted October 1, 2021 Share Posted October 1, 2021 (edited) I used to use only model technics straight castor fuel then 5percent nitro in my then new magnum gp40. Yes it did get a little grubby but was easy to clean, mainly so cooling was as oe. My local club then started to sell an other brand of fuel which I used, quite a bit off. This also made the engine grubby leaving a clear hard varnish type coating on the outside of the engine, quite similar in appearance to that on your Irvine. It was much more difficult to removed, but ran well enough on that fuel. Gold something or other it was. I don't have the gallon plastic container anymore.... How do people using Weston's fuel get on, grubby engine result or clean engine ? Weston's do not use castor in any of Thier fuels I was told when I asked them. I use model technics fuels now with castor. I am not knocking Weston's fuels, I my have to buy that in future, a good deal on 4 gallons mail order, free delivery... Edited October 1, 2021 by Rich Griff Quote Link to comment Share on other sites More sharing options...
J D 8 Posted October 2, 2021 Author Share Posted October 2, 2021 I am having trouble getting the rear bearing out, the usual heat the casing and whack on lump of wood is not working. Problem is the coating limits how hot you can get it without damage. The red coating is still in good order and I would like to keep it. Went to my local Lawn mower chap this morning but none of his internal bearing pullers would fit. Head cleaned up well though after a good boiling and then a Dremel with rotary stainless steel brush. Quote Link to comment Share on other sites More sharing options...
J D 8 Posted October 3, 2021 Author Share Posted October 3, 2021 Got rear bearing out, Found in my box of bits an old type expanding bolt used to fix things into concreate. Once tightened in the bearing inner it gripped very well, a spin then made sure it was only holding in the bearing and not the casing. A dose of boiling water over the casing and then set up as in pic then two good taps had it out. The one with the blue pipe on it was a first attempt with a Rawl bolt but it did not grip enough. 4 Quote Link to comment Share on other sites More sharing options...
Nigel R Posted October 4, 2021 Share Posted October 4, 2021 On 01/10/2021 at 12:40, Rich Griff said: How do people using Weston's fuel get on, grubby engine result or clean engine ? Clean, no signs of anything baking on. Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted October 4, 2021 Share Posted October 4, 2021 hello JD 8,what an excellent idea, well done, send it in to the mag,worthy of a prize. ken anderson...ne..1..ideas dept. Quote Link to comment Share on other sites More sharing options...
J D 8 Posted October 4, 2021 Author Share Posted October 4, 2021 Hi Ken and thanks. The only problem with the Rawl bolt it was not big enough, one the right diameter would work and they are available at any builders merchant. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted October 4, 2021 Share Posted October 4, 2021 Too late now but you might have been able to sleeve the smaller modern rawlbolt with some ali sheet (drinks can?) or similar. Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted October 4, 2021 Share Posted October 4, 2021 Engineuety at it's best. 1 2 Quote Link to comment Share on other sites More sharing options...
J D 8 Posted October 5, 2021 Author Share Posted October 5, 2021 Good service from Simply bearings and Royal Mail. Ordered yesterday afternoon and here today at the edge of the world, well the edge of Wales anyway. 1 Quote Link to comment Share on other sites More sharing options...
J D 8 Posted October 6, 2021 Author Share Posted October 6, 2021 All going good, bearings in fine and all spinning nice, then fitted the prop driver with its collet and did up a prop in the normal way only for everything to lock up solid. Prop driver had split making it jam on the casing. It is an old very used engine. Ah well, another one will turn up sometime. 1 Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted October 6, 2021 Share Posted October 6, 2021 When I was searching for merco parts, I was given a possible supplier from a forum member. I will back track on the threads later this evening to try and find the possible supplier... 1 Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted October 6, 2021 Share Posted October 6, 2021 I suspect it may be the same as a 53 driver - if so, I've got a spare one. If it's any use, PM me your postal address... Quote Link to comment Share on other sites More sharing options...
J D 8 Posted October 6, 2021 Author Share Posted October 6, 2021 Thanks Martin, will see if I can find it is the same driver. Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted October 7, 2021 Share Posted October 7, 2021 If JD 8 can't help let me know. I have a few red Irinves in the breakers box. Pretty sure there is a 46 in there. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.