Piers Bowlan Posted June 15, 2016 Share Posted June 15, 2016 Sorry, not aircraft related but I wondered if one of you engine buffs out there can help me with a problem with this engine, it's is in a four year old strimmer. It fires OK and, with the choke out, will start and give a short burst before dieing. After a bit of perseverance it keeps running with the choke out - then dies. After several attempts, presumably when it has warmed up a bit it will run rather lumpily with the choke in, but any attempt to open the throttle will cause it to instantly die. It seems like it is a fuel starvation problem, so is it is getting a lean cut when I open the throttle? It may well have some fuel residue clogging up the carb as a result of the winter lay off but is stripping the carb down with some carb cleaner the only thing to do now? Should I try something else first? What else should I check. I did clean the air filter by the way. All suggestions gratefully received. Quote Link to comment Share on other sites More sharing options...
Eagle 899 Posted June 15, 2016 Share Posted June 15, 2016 I had the same problem with my hedge trimmer (not Ryobi). It turned out that the carb had become slightly loose and was allowing excess air in. Refitted the carb using threadloc, problem solved. HTH Shep Edited By Eagle 899 on 15/06/2016 10:37:47 Quote Link to comment Share on other sites More sharing options...
flight1 Posted June 15, 2016 Share Posted June 15, 2016 Have you tried new fresh fuel? as you said been laid up and with all the ethanol in the petrol can cause problems. If you got a new spark plug at hand try that first , then i would get some B3C mechanic in a bottle use as directed . for general use get some B3C Ethanol Shield Fuel Stabilizer for long laups or or use thier two stroke oil like from here they do a smaler bottle as well Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted June 15, 2016 Share Posted June 15, 2016 If you've checked fuel tubing etc google a video to help with carb sorting Quote Link to comment Share on other sites More sharing options...
Subalib Posted June 15, 2016 Share Posted June 15, 2016 Not sure what brand of carby is fitted but the symptoms suggest that the metering diaphragm has hardened. If it is a Walbro style of carby the diaphragm is easy to replace as it is under the metal cover that is held on by 4 Philip head screws. Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted June 15, 2016 Author Share Posted June 15, 2016 Shep, yes the carb is secure but it would have been a nice simple fix if that had been the cause. Thank you Flight1, B3C Mechanic is on order with Amazon as it looks like good stuff. I will let you know how it goes. John, I have watched several videos, so I am now a Ryobi expert - I hope! I am about to strip the carby down and hope to find some foreign objects causing an obstruction which again would be a simple fix. I will probably need to get a new gasget set so replacing the diaphragm at the same time would be sensible Subalib, so thanks for that. I noticed the priming bulb reluctant to fill with fuel and prime so I will be checking the fuel lines, tank and filter for leaks. Thank you one and all, I will keep you informed... Quote Link to comment Share on other sites More sharing options...
cymaz Posted June 15, 2016 Share Posted June 15, 2016 Have you cleaned the air cleaner, by chance?. Easy to do while everything is in bits. Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted June 16, 2016 Author Share Posted June 16, 2016 Yes Cymaz I cleaned it, although it looked OK. I also tried to start it without the air filter but with no improvement. Thanks for your input. Quote Link to comment Share on other sites More sharing options...
Andy48 Posted June 16, 2016 Share Posted June 16, 2016 I had a Ryobi strimmer. Basically it was cr**. It was very very susceptible to the wrong fuel oil mixture. It needed to be exactly right otherwise I got the same problems as the OP. Eventually replaced it with a Titan one from Screwfix, which runs a dream and has a super starter system on it. Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted June 16, 2016 Share Posted June 16, 2016 The fuel filter/clunk is felt filter and these can clogg with congealed oil . fit a new one first . Next look at changing carb diaphragm and filters. These don't last more than a couple of years usually and with the modern fuel seem to fail even more frequently. Fresh fuel with decent oil will also help. No need for expensive synthetic oil . Autolube two stroke from most supermarkets is a decent oil and is only £2 for half a litre from Morrison's. Spark plug should be oknas it is starting but if when you get it started it misfires when you rev it replacecthe plug. Provided the engine is mechanically sound these measures should get it up and running. Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted June 16, 2016 Share Posted June 16, 2016 Looked at a strimmer for a mate a couple of weeks ago with exactly the same symptoms. Turned out to be a blocked filter in the fuel tank - runs a treat now. Quote Link to comment Share on other sites More sharing options...
Shaunie Posted June 16, 2016 Share Posted June 16, 2016 As its a four stroke, I remember reading somewhere that these can have a plastic camshaft! **LINK** There you go! Don't know if it's relevant but worth checking. Shaunie Quote Link to comment Share on other sites More sharing options...
onetenor Posted June 16, 2016 Share Posted June 16, 2016 Petrol deposit remover works well too. Having done everything else as advised adjust valve clearances too. Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted June 16, 2016 Share Posted June 16, 2016 That threw me  good and proper , never heard of that .A four stroke with a plastic camshaft , almost a april fool joke ! Do Ryobi make chocolate tea pots and glass nails ? Edited By Engine Doctor on 16/06/2016 20:37:58 Quote Link to comment Share on other sites More sharing options...
Andy48 Posted June 16, 2016 Share Posted June 16, 2016 Said they were cr**! Quote Link to comment Share on other sites More sharing options...
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