tsiklonaut Posted August 16, 2018 Author Report Share Posted August 16, 2018 (edited) Cheers guys, some good tips on making a simple specialised plate removal tool. I'll seek into that once I'm there... Edited August 16, 2018 by tsiklonaut Quote Link to comment Share on other sites More sharing options...
tsiklonaut Posted August 18, 2018 Author Report Share Posted August 18, 2018 (edited) Opened the LHS case and a gulp of confirmed gearbox oil came out whre it's not supposed to be. Also found some suspicious rubber strips, apparently peeled off from the seal so I think I've found the devil - a failed O-ring. Replaced with high quality high-pressure seal (made for hydraulic pumps). Lets see if it last longer. After a longer run to clear residual oil from the exhaust - not smoking anymore, and now runs so sweet! Edited August 18, 2018 by tsiklonaut Quote Link to comment Share on other sites More sharing options...
ric h Posted August 18, 2018 Report Share Posted August 18, 2018 (edited) Those strips look like they are from installation of the original seal.If the bore it fits into has a really sharp edge,it will cut some of the outer rubber off.Be extremely careful with the tiny o-ring installation.(i use heavy grease to keep it in place)If it doesn't seal properly or blocks the oil passage,you will for sure damage the main bearing. Edited August 18, 2018 by ric h Quote Link to comment Share on other sites More sharing options...
tsiklonaut Posted August 18, 2018 Author Report Share Posted August 18, 2018 3 hours ago, ric h said: Those strips look like they are from installation of the original seal.If the bore it fits into has a really sharp edge,it will cut some of the outer rubber off.Be extremely careful with the tiny o-ring installation.(i use heavy grease to keep it in place)If it doesn't seal properly or blocks the oil passage,you will for sure damage the main bearing. Could be, or could be the bearing is loose to strip a lip off the seal. The particular needle bearing gets its oiling from a separate channel (coming from two small holes you see below the big seal below the last pic) and it was well oiled as you could tell from the leak, lol. Those two o-rings both sides of the bearing are only to stop oil from getting into crank or magneto chamber, so the bearing gets it's oil anyway and you cannot block them with those o-rings, so the question is if it leaks into a place where it doesn't belong which was my case of leaking into crank chamber. Quote Link to comment Share on other sites More sharing options...
canada280i Posted August 18, 2018 Report Share Posted August 18, 2018 Did you make a homemade puller? If so let’s see it, I like to marvel at ingenuity 1 Quote Link to comment Share on other sites More sharing options...
tsiklonaut Posted August 20, 2018 Author Report Share Posted August 20, 2018 (edited) On 8/18/2018 at 11:06 PM, canada280i said: Did you make a homemade puller? If so let’s see it, I like to marvel at ingenuity A good mate of mine made it, he's a technical wizard and even better trials rider. It's a finely machined and welded semi circle, that just fits the three alternator bolts inside (remove the alternator, stick the same bare bolts back inside, turn the semi circle around them and just pull the cover off, easy as that!), even made a spacer support that centers on the crank hole so it has a surface to rotate on. It's a top quality handwork, even the expensive pro grade tools have hard time to catch that kind of quality Edited August 20, 2018 by tsiklonaut 1 2 Quote Link to comment Share on other sites More sharing options...
canada280i Posted August 20, 2018 Report Share Posted August 20, 2018 See......ingenious Quote Link to comment Share on other sites More sharing options...
lotus54 Posted August 21, 2018 Report Share Posted August 21, 2018 Would he make more? Quote Link to comment Share on other sites More sharing options...
peterb Posted August 22, 2018 Report Share Posted August 22, 2018 Just looking at the photo of the inner plate with oil seal, it's hard to be sure but I wonder if the oil seal was in the wrong way around, you should be able to see oil seal spring from this view, the spring always faces the pressure side, in this case the crankcase inner. With the replacement seal, this should be in viton due to the temperature limitations of other usual seal materials. Bye, PeterB. Quote Link to comment Share on other sites More sharing options...
ric h Posted August 22, 2018 Report Share Posted August 22, 2018 Pretty sure the seal is correctly installed.The oil pressure is on the bearing side,not the crankcase side as per usual 2 stroke design. Quote Link to comment Share on other sites More sharing options...
peterb Posted August 23, 2018 Report Share Posted August 23, 2018 Hi Ric, I disagree, there is no oil pressure, from the gearbox to the needle roller it is a gravity fed system, oil is tapped off between two tapping points through the crankcase to the bearing. Always, the spring of an oil seal faces the pressure side of a housing, in this case the pressure side is the crankcase. But, I can't tell from the photo if the side we can see is the spring side or not, it does not appear correct. I'll have a look at a spare Ossa seal and let you know. Bye, Peter B. Quote Link to comment Share on other sites More sharing options...
ric h Posted August 23, 2018 Report Share Posted August 23, 2018 I'm well aware which side of the seal is pressure. (retired hydraulics tech) I have always assumed there was "some" pressure on the inside of the bearing race.Oil can't be compressed.The other side can.My Workshop manual doesn't clearly illustrate.Need input from someone else.Or...i could be wrong. Quote Link to comment Share on other sites More sharing options...
pauls320 Posted August 23, 2018 Report Share Posted August 23, 2018 Pressure is on crankcase side, tension spring side of the seal faces inboard towards conrod Quote Link to comment Share on other sites More sharing options...
peterb Posted August 23, 2018 Report Share Posted August 23, 2018 (edited) Here is a photo of my 2013 Ossa inner plate, that I removed to replace with a ball race conversion plate. It has the original oil seal in place. This is different to tsiklonaught's photo which I reckon is in the wrong way round and is very likely the cause of the gearbox oil entering the crankcase. Bye, Peter B. Edited August 23, 2018 by peterb Photo attached Quote Link to comment Share on other sites More sharing options...
section swept Posted August 23, 2018 Report Share Posted August 23, 2018 On 18/08/2018 at 4:15 PM, tsiklonaut said: Opened the LHS case and a gulp of confirmed gearbox oil came out whre it's not supposed to be. Also found some suspicious rubber strips, apparently peeled off from the seal so I think I've found the devil - a failed O-ring. Replaced with high quality high-pressure seal (made for hydraulic pumps). Lets see if it last longer. After a longer run to clear residual oil from the exhaust - not smoking anymore, and now runs so sweet! Oil seal deffo wrong way round Quote Link to comment Share on other sites More sharing options...
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