Albert 888 Posted April 30, 2017 Report Share Posted April 30, 2017 (edited) Long story cut short. Im having bother bedding in my rings,its blowing oil out the breather pipe on the rocker cover. From what info I can find on the net I have a few options. Run in hard or run in 1/3 throttle lots of deceleration using engine braking. Any of you guys actually changed rings on a four-stroke and been successful. Have new rings ready to fit but weighing up my options. Edited April 30, 2017 by Albert 888 Quote Link to comment Share on other sites More sharing options...
Rupert Posted April 30, 2017 Report Share Posted April 30, 2017 How long you been trying? Quote Link to comment Share on other sites More sharing options...
Albert 888 Posted April 30, 2017 Author Report Share Posted April 30, 2017 On an off around 2 month. First I slipped up and used fully synthetic oil when I fit new piston and rings,second time new rings a chip came off an oil scraper ring but didn't notice it.in-between I've been stripping it down and deglasing the bore lightly oiling the bore using 10/40 mineral oil that's also in the engine and box. I don't want to knacker another set of rings,they are special order from ktm Austria. Quote Link to comment Share on other sites More sharing options...
Me matt Posted April 30, 2017 Report Share Posted April 30, 2017 I got shot of my 450EXC after the balance shaft snapped and split the case in two 😐 I've broken a few KTMs, never attempted tonfix a single one. Have you asked on a more related forum? Try here ; http://www.ktmforum.co.uk/content/ There's a guy called kevinyorks - he'll put you right 👍 Quote Link to comment Share on other sites More sharing options...
Rupert Posted April 30, 2017 Report Share Posted April 30, 2017 Oil ring stuck Quote Link to comment Share on other sites More sharing options...
Albert 888 Posted April 30, 2017 Author Report Share Posted April 30, 2017 (edited) Yes I have and Kevin has been a great help. I tried his method of the 1/3 throttle and loads of engine breaking but I stupidly put fully synthetic in it. Im looking to get as much info as I can before I change them again. Oil ring stuckNo they are free, all 120 degrees apart and the oil spring is butted up not overlapping. Edited April 30, 2017 by Albert 888 Quote Link to comment Share on other sites More sharing options...
Me matt Posted April 30, 2017 Report Share Posted April 30, 2017 Well as you now know- running in shouldn't be done with FS. Sounds like you'll be needing another set of rings to me. Just out of interest - what year is it? Quote Link to comment Share on other sites More sharing options...
Albert 888 Posted April 30, 2017 Author Report Share Posted April 30, 2017 I have a new set ready,it's an 07. Quote Link to comment Share on other sites More sharing options...
Hendrix's rifle Posted April 30, 2017 Report Share Posted April 30, 2017 Nikasil plated cylinder so don't need running in just get on and go. There's a chance it needs replating if it won't work. How does it run? Under powered? Don't forget there race bikes and as such you can't spend 4 hours running a piston in if you have to change it last minute. My 525 and a few other bikes I've had that are nikasil plated have never needed running in. If you 2ant to know anything pm me and il give you my number and have a chat in the phone about it Quote Link to comment Share on other sites More sharing options...
Me matt Posted April 30, 2017 Report Share Posted April 30, 2017 (edited) Nikasil plated cylinder so don't need running in just get on and go. Really? When I bought a new 6 days from Jim Aims it came with mineral break in oil that I had to change after a few hours progressive riding...... Edited April 30, 2017 by Me matt Quote Link to comment Share on other sites More sharing options...
Albert 888 Posted April 30, 2017 Author Report Share Posted April 30, 2017 Reading between the lines on all the info I have read,mineral oil is a must as it burns off in the chamber and bore, then the deceleration and forces produced forces the oil rings out. Now it's 50/50 weather I ride it hard or gently run it in going up and down through the gears and not letting the engine struggle. It's got loads of compression and power for the size of bore even though it's passing oil out the breather . I only changed the piston and rings as I split the engine to replace the semi sized big end. Had loads of compression and power before, bore was spotless and piston and ring looked quite good and it wasn't smoking or using oil. Quote Link to comment Share on other sites More sharing options...
Wb123 Posted April 30, 2017 Report Share Posted April 30, 2017 I always used to give the cylinder a quick hone to deglaze till just rough to the thumbnail when changing rings. Never worried about running in after that and seemed to get away with it. Is it definitely blowing past the rings? Could you have cooked or unseated your valve stem seals? Quote Link to comment Share on other sites More sharing options...
Albert 888 Posted April 30, 2017 Author Report Share Posted April 30, 2017 I deglased it with a flapper wheel by hand and crosshatched it. I thought about the valve seals but then it would burn oil smoke or make the exhaust manifold glow red. It was OK before. I blocked the breather pipe on purpose and it pressurised the crankcase and blew the gear selector oil seal out. Quote Link to comment Share on other sites More sharing options...
Hendrix's rifle Posted May 1, 2017 Report Share Posted May 1, 2017 Really? When I bought a new 6 days from Jim Aims it came with mineral break in oil that I had to change after a few hours progressive riding...... Yeh, don't need a break in with piston and rings. Gearbox may be different. You have an event, at practise just prior you notice it's low on compression, you change piston and or rings. You think you have time to bed them in? Steel bore the fair enough but like I said its plated for a reason. If your competing you don't have time to bed a new one in. Bmw did the same thing in one of there cars I think it was an m3 a few years back, unfortunately for them the plating was an issue and had a few problems with them. I deglased it with a flapper wheel by hand and crosshatched it. I thought about the valve seals but then it would burn oil smoke or make the exhaust manifold glow red. It was OK before. I blocked the breather pipe on purpose and it pressurised the crankcase and blew the gear selector oil seal out. Did you check all gaskets were correct and oil ports were unobstructed? Could be a reason for over pressure Quote Link to comment Share on other sites More sharing options...
Albert 888 Posted May 1, 2017 Author Report Share Posted May 1, 2017 Everything was spot on,cleaned everything in the pats cleaner at work,all oilways clear as I blew them out with compressed air. I used ktm genuine gaskets. Quote Link to comment Share on other sites More sharing options...
Hendrix's rifle Posted May 1, 2017 Report Share Posted May 1, 2017 Did you gap the rings? They may be out of spec from the factory. If the rings have too big a gap pressure can return down them pressurising the crank cases. If you didn't measure them that's the first thing id be checking Quote Link to comment Share on other sites More sharing options...
Albert 888 Posted May 1, 2017 Author Report Share Posted May 1, 2017 I didn't gap the rings,will have a look how to do it thanks. I just presumed they would be ok,I always seam to learn the hard way, atleast I won't forget. Quote Link to comment Share on other sites More sharing options...
Albert 888 Posted May 1, 2017 Author Report Share Posted May 1, 2017 Sorted now thanks, gap is 004" per inch of bore. insert ring into bore measure gap with feeler gauges and file to suit,do compression ring and the two oil scraper rings. Quote Link to comment Share on other sites More sharing options...
Hendrix's rifle Posted May 1, 2017 Report Share Posted May 1, 2017 With a bit of luck that should sort you out. We've all done it before wiseco pistons come with a data sheet for measuring gapd dependint on what your doing with it for e.g., dirt riding, fast street and drag racing with nitro fuel and what not. Quote Link to comment Share on other sites More sharing options...
Albert 888 Posted May 2, 2017 Author Report Share Posted May 2, 2017 Gaps measured New rings Compression ring 008" Oil scraper rings 018" Quote Link to comment Share on other sites More sharing options...
bornfree Posted May 2, 2017 Report Share Posted May 2, 2017 I wouldn't do it on your KTM but years ago when I worked on lister engines we had a lot of blow by problems on canal barges ( caused by light loads and low revs for hours) now the official job was strip down and deglaze the bores. But we used to get them hot by tying the barge up and revving them flat out the take off the air filter and sprinkle some vim down the intake. It worked in a couple of minutes. Quote Link to comment Share on other sites More sharing options...
Saltings Posted May 3, 2017 Report Share Posted May 3, 2017 (edited) as above vim will give you a second chance at bedding the rings in together with mineral oil until run in, synthetics glaze the bores and will not allow the rings to bed in if it fails a strip down and rebuild vim has got me out of trouble a few times Edited May 3, 2017 by Saltings Quote Link to comment Share on other sites More sharing options...
Albert 888 Posted May 4, 2017 Author Report Share Posted May 4, 2017 Stripped it down cleaned it all up rode it lively and I had no oil out the breather BUT the pig dropped an exhaust valve and snaped it and gauged the valve seat,just bought a second hand one will fit when it arrives. Im buying a two-stroke next Quote Link to comment Share on other sites More sharing options...
Me matt Posted May 4, 2017 Report Share Posted May 4, 2017 I feel your pain ☹ I had a 2007 exc 400 that dropped a valve, was on full chat at the time...... It was terminal Quote Link to comment Share on other sites More sharing options...
Albert 888 Posted May 4, 2017 Author Report Share Posted May 4, 2017 Oh dear it does look bad. Mine not too bad I can recycle my old piston use the new rings and fitting a good used head and valves, new ones are £100 a pop,I'm definitely going two-stroke next, will just have to learn to use the rear brake,it's not that bad as my mate has broke his wrist whilst on the trials bikes so been borrowing his 250 exc. Quote Link to comment Share on other sites More sharing options...
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