Rory Posted August 17, 2014 Share Posted August 17, 2014 (edited) Hi FolksI posted a little while ago looking for help with my LRP 28 engine, Ive taken some pics now to see if anyone can spot anything I cant.The last time I took it out it ran ok for the first 5 mins of gentle warm up, then died and refused to restart. Since then Ive tried factory settings, different fuel, new glow plugs, checked glow charger etc. The best Ive managed to coax out of it is a poor run which sounded buzzy and just not the right note at all.The engines only had about 3-4 litres of fuel.It sounded similar to when I had the cylinder liner lined up incorrectly a while ago, i.e the notches in crankcase and liner weren't lined up. But having taken the head off, its still lined up correctly. So here are the pics, any help is much appreciated! Edited August 27, 2014 by Rory Quote Link to comment Share on other sites More sharing options...
mickturnip Posted August 17, 2014 Share Posted August 17, 2014 Wher ya from fella if local I wood glady help you out Quote Link to comment Share on other sites More sharing options...
Rory Posted August 17, 2014 Author Share Posted August 17, 2014 Wher ya from fella if local I wood glady help you outIm probably not local , Im outside Glasgow lol. Turning the engine over by hand there is a noticeable sticky point at TDC but is that just the normal pinch of a newish engine? Quote Link to comment Share on other sites More sharing options...
locky Posted August 17, 2014 Share Posted August 17, 2014 Cant see anything. I've just got LRP Spec 3 28 and breakin it in still. Have you removed the cylinder before? Are you re-sealing the backplate with gasket sealant or similar? Have you re-sealed the carb? Checked for splits in fuel tubing? Does buzzy mean it sounds lean? That could be an air leak. Quote Link to comment Share on other sites More sharing options...
locky Posted August 17, 2014 Share Posted August 17, 2014 Im probably not local , Im outside Glasgow lol. Turning the engine over by hand there is a noticeable sticky point at TDC but is that just the normal pinch of a newish engine? Yes, is it a new engine or second hand? Have you tuned nitro engines before? Quote Link to comment Share on other sites More sharing options...
Rory Posted August 17, 2014 Author Share Posted August 17, 2014 Cant see anything. I've just got LRP Spec 3 28 and breakin it in still. Have you removed the cylinder before? Are you re-sealing the backplate with gasket sealant or similar? Have you re-sealed the carb? Checked for splits in fuel tubing? Does buzzy mean it sounds lean? That could be an air leak.Ive removed the cylinder before yeah, was just having a nosey when it was new and accidentally pulled the liner up.Engine ran fine when back in place and all put back together.When I say buzzy I don't mean lean, I mean rough and lumpy and just not like a sweet engine runs. Quote Link to comment Share on other sites More sharing options...
mickturnip Posted August 17, 2014 Share Posted August 17, 2014 That piston is brown .....runnin too lean ...also it looks like theres rust on the crank ...for such a new engine shouldnt be like that ......wen my lrp 32 block cracked (due to peel park jumpin) been in for 15month about 4 gallons through it .I stripped it and the piston was silver no brown marks on it like the one in pics Quote Link to comment Share on other sites More sharing options...
Rory Posted August 17, 2014 Author Share Posted August 17, 2014 Im an experienced nitro user, the engine was new when I got it and it was run in carefully.I did accidentally run it a bit lean for 10 minutes, could that have warped something? Quote Link to comment Share on other sites More sharing options...
mickturnip Posted August 17, 2014 Share Posted August 17, 2014 That could have damaged it and confirms why the piston is brown ....been very hot .could have scord the piston and liner .... Quote Link to comment Share on other sites More sharing options...
Rory Posted August 17, 2014 Author Share Posted August 17, 2014 That could have damaged it and confirms why the piston is brown ....been very hot .could have scord the piston and liner ....Ive had nitro for years and never ruined an engine but I think doing doughnuts without much air flow and the bottom end too lean might have knackered it oh dear Quote Link to comment Share on other sites More sharing options...
mickturnip Posted August 17, 2014 Share Posted August 17, 2014 Yeah ..that will have overheated it ..can you see any scoring on the liner then Quote Link to comment Share on other sites More sharing options...
locky Posted August 17, 2014 Share Posted August 17, 2014 Do you get good compression with glow plug fitted? Not sure that running lean for short time will knacker it so quickly. Do you know the needle settings well? Tried leaning it out a bit from default? I've only leaned HSN by 1/4 turn so far and runs good, if a little rich, but taking it easy. Not touched LSN. Do you monitor your temps? Quote Link to comment Share on other sites More sharing options...
locky Posted August 17, 2014 Share Posted August 17, 2014 I'm not sure the colour means its been running lean, have a search and see what you think. Quote Link to comment Share on other sites More sharing options...
mickturnip Posted August 17, 2014 Share Posted August 17, 2014 Means its burn the oil in the fuel more rather then usin more oil to lube the the movin parts ......the nitro content burns and cools the oil content lubricates .....run lean means engine gets hot and the oil content in the fuel burns therfore less oil is used to lubricate ......classic sign brown piston .....tne nitro ignites at a lower temp then the oil ..thus oil drops from exhaust ..... Quote Link to comment Share on other sites More sharing options...
Rory Posted August 17, 2014 Author Share Posted August 17, 2014 Do you get good compression with glow plug fitted? Not sure that running lean for short time will knacker it so quickly. Do you know the needle settings well? Tried leaning it out a bit from default? I've only leaned HSN by 1/4 turn so far and runs good, if a little rich, but taking it easy. Not touched LSN. Do you monitor your temps?I put it back to factory after it stopped running, then leaned in a little as I know factory is super rich. I usually always monitor temps when I run but the time I now know it was a bit lean I didn't.I didn't see any scoring on the liner. It has lots of compression, Im very confused why it wont fire. Definitely getting fuel in. Maybe a carb issue, might see if anything is blocking that. Quote Link to comment Share on other sites More sharing options...
locky Posted August 18, 2014 Share Posted August 18, 2014 Do you have a fuel filter that needs checking? Quote Link to comment Share on other sites More sharing options...
RCbutcher Posted August 18, 2014 Share Posted August 18, 2014 It looks rough it's the first engine I've seen look like that with so little run time mayb you tuned it right but something made it lean anyway. I would pull it all apart clean all the internals with the dremmels wire brush bit scrub it with nitro fuel then rinse it with new fuel making sure no bits are left inside. Then check the bearings don't leak front bearing especially then strip the carb down take the needles out and flush the whole thing with fresh nitro fuel making sure there's nothing in there blocking fuel flow. I did all of that with a new picco engine that the original buyer could not get running and sold it on. After the full strip , clean and seal plus I found a small flake of metal stuck to the tip of a needle it started running perfect. Bolting it up with the head backwards might have caused some damage a good strip won't solve tho or mayb even knocked the timing out idk if that's possible but something to look into if strip clean doesn't work. Quote Link to comment Share on other sites More sharing options...
Rory Posted August 20, 2014 Author Share Posted August 20, 2014 Well I think its warped internally. Put it back together and ran it again tonight, got a few minutes of it running but still didn't sound right, sounded sticky. Temps also got high much quicker than normal, it just wasn't sweet at all.So maybe at some point I'll come back to it and try to overhaul it, but in the meantime going to buy somethingelse to throw in the ST. Quote Link to comment Share on other sites More sharing options...
Anthoop Posted August 21, 2014 Share Posted August 21, 2014 What fuel are you using? I would not imagine anything inside the engine is warped, if it still has compression then it should work. I expect there is a carb. blockage or problem....or a fuel supply problem. 1 Quote Link to comment Share on other sites More sharing options...
Rory Posted August 21, 2014 Author Share Posted August 21, 2014 What fuel are you using? I would not imagine anything inside the engine is warped, if it still has compression then it should work. I expect there is a carb. blockage or problem....or a fuel supply problem. I've tried 2 fuels in it. It doesn't sound like it's lean at all, it's not running away at high revs. It sounds rough. I lifted it off the ground and gunned it and it did rev up high with lots of smoke so I'm sure it's getting fuel ok. Turning it over by hand it's very sticky at tdc, I can't remember if it was that bad before. Quote Link to comment Share on other sites More sharing options...
locky Posted August 21, 2014 Share Posted August 21, 2014 Did you remove the carb and needles and give them a clean? I just cleaned my fuel filter and its was full of crap. Quote Link to comment Share on other sites More sharing options...
Rory Posted August 21, 2014 Author Share Posted August 21, 2014 Did you remove the carb and needles and give them a clean? I just cleaned my fuel filter and its was full of crap. No I didn't , I guess I can try but don't expect that to be the problem Quote Link to comment Share on other sites More sharing options...
Rory Posted August 27, 2014 Author Share Posted August 27, 2014 Ive fixed it - what an idiot I am! lolTaking it apart to put a new engine in, I find the clutch spring broken. It just has a 2 shoe clutch so one spring wraps around the shoes. I checked the clutch by spinning it which it managed to do, but on taking it apart I could see the spring was broken and was allowing the shoes to drag all the time.Quick spring change and its running perfectly again.So now I have a spare axial 28 engine ... maybe gives me a good excuse to get a roller to put it in Quote Link to comment Share on other sites More sharing options...
Anthoop Posted August 28, 2014 Share Posted August 28, 2014 (edited) Well...glad it is fixed. ...but this thread shows how hard it can be to diagnose a problem with the written word...and even pictures... Edited August 28, 2014 by Anthoop 1 Quote Link to comment Share on other sites More sharing options...
locky Posted August 29, 2014 Share Posted August 29, 2014 Good news, just takes time and some patience. Thought you couldnt damaged the engine. What pipe are you using with it? Quote Link to comment Share on other sites More sharing options...
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