netley Posted August 23, 2018 Report Share Posted August 23, 2018 Just used my 1981white wonder 349 after a couple of months standing. After an hour of blatting about on a testing trial I noticed an oil leak, which seemed emulsified, from the plug below gear lever and then shortly after bubbling from clutch actuating arm where it goes into the engine case. What could be the cause? Is an engine strip/rebuild on the cards? I haven't touched the engine since I've owned it. Any advice gratefully received. Cheers. Neil Quote Link to comment Share on other sites More sharing options...
feetupfun Posted August 24, 2018 Report Share Posted August 24, 2018 Sounds like the casing has pressure inside for some reason. Maybe the vent is blocked and when the motor warms up due to expansion of the gas inside it generates pressure that is not being relieved. Could also be a drive side crank seal leaking. 1 Quote Link to comment Share on other sites More sharing options...
peterb Posted August 25, 2018 Report Share Posted August 25, 2018 It's possible that you were riding through a stream and water was sucked into the gearbox and clutch, hence the emulsified oil. I'd drain the oil and run a flush through it then try it out with fresh oil. Bye, Peter B. 1 Quote Link to comment Share on other sites More sharing options...
netley Posted August 25, 2018 Author Report Share Posted August 25, 2018 No water involved. Quote Link to comment Share on other sites More sharing options...
netley Posted August 25, 2018 Author Report Share Posted August 25, 2018 On 24/08/2018 at 3:45 AM, feetupfun said: Sounds like the casing has pressure inside for some reason. Maybe the vent is blocked and when the motor warms up due to expansion of the gas inside it generates pressure that is not being relieved. Could also be a drive side crank seal leaking. I thought it would have to come apart at some point. The rest of the bike is pretty tatty so I think it's had a tough life. Quote Link to comment Share on other sites More sharing options...
section swept Posted August 25, 2018 Report Share Posted August 25, 2018 Condensation in the transmission oil. Blocked breather allowing hot oil gassing to build up pressure forcing oil out of easiest escape route usually an oil seal lip. This doesn’t mean the seal is shot just that the lip has lifted slightly to allow the pressure out. Drain oil, check breathers for blockages, check drained oil for metal particles or worse...hopefully it’ll just be cruddy oil. Fit drain plug back, tip into gearbox some white spirit or similar and shake bike about to stir up the spirit rock bike back and forth, drain spirit and leave to drain for a few minutes. Fresh oil back in and try again. ?? 1 Quote Link to comment Share on other sites More sharing options...
netley Posted August 25, 2018 Author Report Share Posted August 25, 2018 That sounds, hopefully, like it could be a possibility. I'd certainly take that as a result. I will look in to it but probably not until the end of next month due to house moving. Cheers. Neil. Quote Link to comment Share on other sites More sharing options...
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