kevlarr Posted October 18, 2019 Report Share Posted October 18, 2019 Evening, I have to replace crank bearings on my ST 300 Factory 2016, I have been quoted silly money for labour to have a shop do the work so am thinking of doing my self. Any advice or tips would be helpful. TIA. Kev Quote Link to comment Share on other sites More sharing options...
suzuki250 Posted October 18, 2019 Report Share Posted October 18, 2019 (edited) Does it need the bigend replacing or just main bearings? Edited October 18, 2019 by suzuki250 Quote Link to comment Share on other sites More sharing options...
faussy Posted October 18, 2019 Report Share Posted October 18, 2019 (edited) You do know its a pretty big job for the uninitiated? Do you have the tools to do it correctly? A flywheel puller, bearing puller Are you sure its silly money? Edited October 18, 2019 by faussy Quote Link to comment Share on other sites More sharing options...
lineaway Posted October 19, 2019 Report Share Posted October 19, 2019 Having to have it redone again is really silly. Have you ever split a motor before? Quote Link to comment Share on other sites More sharing options...
huski Posted October 19, 2019 Report Share Posted October 19, 2019 How much have you been quoted? Quote Link to comment Share on other sites More sharing options...
kevlarr Posted October 19, 2019 Author Report Share Posted October 19, 2019 Bike was smoking and was told that bearing seals needed replacing , £200 later and still smoking . Now quoted £240 labour plus parts for bearings if I take engine out, I have access to pullers etc I have never done it but thought this may be an ideal time to learn. I have no time limit, it takes as long as it takes. Thanks for your replies. Quote Link to comment Share on other sites More sharing options...
2stroke4stroke Posted October 19, 2019 Report Share Posted October 19, 2019 £40 more than just the seals sounds infeasible, but £200 to change seals is somewhat OTT I would have thought. I would expect RYP website to have a video but Sherco owners may give more detail. Quote Link to comment Share on other sites More sharing options...
faussy Posted October 19, 2019 Report Share Posted October 19, 2019 (edited) 1 hour ago, kevlarr said: Bike was smoking and was told that bearing seals needed replacing , £200 later and still smoking . Now quoted £240 labour plus parts for bearings if I take engine out, I have access to pullers etc I have never done it but thought this may be an ideal time to learn. I have no time limit, it takes as long as it takes. Thanks for your replies. Cant you take it back to the guy that did the initial work and tell him his fix wasn't a fix? 240 with the engine already out is excessive, id be expecting around 150, to a bike mechanic its maximum a 3 hr job Edited October 19, 2019 by faussy Quote Link to comment Share on other sites More sharing options...
lineaway Posted October 19, 2019 Report Share Posted October 19, 2019 (edited) Well if you really feel the need to do it, it`s a good time of year to waste some time. Once you do it you feel confident to fix about anything in the future. First off leave the motor completely assembled in the frame. This will give you more leverage to get everything apart. Do the flywheel and stator first. Then everything off from the clutch side. The hardest thing and this point will be primary gear on the crankshaft. Take lots of pics and be organized about it. Do not take off the top end, untill you are ready to remove the motor. Now go watch as many u tube vids as you can. Cut up an old inner tube into 4 small strips to hold the transmission togerther once you have split the motor. It really is not hard to take it apart. Remember to always have the transmission in nuetral while splitting the cases and assembling the cases. What fun you are going to have! Edited October 19, 2019 by lineaway 2 1 Quote Link to comment Share on other sites More sharing options...
huski Posted October 19, 2019 Report Share Posted October 19, 2019 What makes you think it needs a rebuild?Is it noisy with more than usual vibration?Does it start and run ok apart from the smoke? Quote Link to comment Share on other sites More sharing options...
kevlarr Posted October 19, 2019 Author Report Share Posted October 19, 2019 Original diagnosis and quote was for seals and didn’t know it wasn’t them until back together and running. Bearings are a little noisy and that is what they believe may be the problem. Starts and runs fine until riding to sections then smokes excessively Thanks for the tips Lineaway Quote Link to comment Share on other sites More sharing options...
b40rt Posted October 19, 2019 Report Share Posted October 19, 2019 Can someone explain why slightly noisy mains would make it smoke excessively, especially if crank seals have just been replaced ? Quote Link to comment Share on other sites More sharing options...
mcman56 Posted October 19, 2019 Report Share Posted October 19, 2019 Starts and runs fine until riding to sections then smokes excessively If the exhaust is full of oil, it may catch fire and smoke excessively when riding to sections. It will also run funny and have a weird smell, sort of like a rancid barbecue. You could be burning off the oil that built up from the bad seals. There are some posts on here about cleaning out the exhaust. Another way is just to run it hard and keep a lot of heat in the exhaust until it burns out. This could be a long ride at the speed it starts smoking on the way to sections or a nice long hill climb. Repeat until it stops smoking. 2 1 Quote Link to comment Share on other sites More sharing options...
lineaway Posted October 19, 2019 Report Share Posted October 19, 2019 (edited) 1 hour ago, b40rt said: Can someone explain why slightly noisy mains would make it smoke excessively, especially if crank seals have just been replaced ? Too much play in the main bearings will cause the seals to leak. But while he is taking it apart I would make sure the seal is new and properly seated. Edited October 19, 2019 by lineaway Quote Link to comment Share on other sites More sharing options...
kevlarr Posted October 19, 2019 Author Report Share Posted October 19, 2019 Mcman56, I did think about oil in exhaust packing as a cause of it still smoking . Do you guys think I should leave alone for a while and see if it calms down. I could change packing first I guess, cheaper option to start with. Quote Link to comment Share on other sites More sharing options...
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