insultaco Posted January 15, 2012 Report Share Posted January 15, 2012 (edited) Hi I have a M159 Bultaco 350 and have consulted both Haynes and Clymer manuals Please can anybody give me a tip for removing the following bobbin that has attached itself to the crank, presumably with the O ring that appears to have died inside it? This bobbin is not mentioned anywhere, but I assume is common as the steps in the crank at this end appear common to more than the 159. Also, please confirm: 1. Remove bobbin 2. Replace O ring (about an inch in diameter) 3. Replace seals in carrier 4. Replace bobbin 5. Replace weight and re-assemble the rest of it etc.. It's just No 1. I can't find any reference to and am struggling to remove! Cheers Mick Edited January 15, 2012 by insultaco Quote Link to comment Share on other sites More sharing options...
naichuff Posted January 15, 2012 Report Share Posted January 15, 2012 The bobbin you talk about is a wear sleave for the seal to sit on rather than groove the crank Yes there is a small O ring between it and the bearing to seal the sleave and shaft. Cannot remember if there is alip on the outer side against the flywheel as I have not had mine of for along time Quote Link to comment Share on other sites More sharing options...
pschrauber Posted January 15, 2012 Report Share Posted January 15, 2012 (edited) The bobbin (Kurbelwellenbüchse) should been removed to replace the the inner O-Ring as you said. May be you need a gear puller to pull it out. After intsalling the crank seal it is first possible to mount the bobbin as the outer surface of the bobbin is the running surface of the outer crank seal. How did come the oil seal of the crank seal off if you did not detach the bobbin? As the seal has to slip over the edge of the bobbin it must have been not so easy? May be it's just some corrosion use some penetrating oil and wait, while attaching a puller small strokes with a small hammer might also help, (no force!). I personal would not try to heat up the shaft of the crank, might change the hardness of the crankshaft. Edited January 15, 2012 by PSchrauber Quote Link to comment Share on other sites More sharing options...
insultaco Posted January 15, 2012 Author Report Share Posted January 15, 2012 Hi and thanks for the replies! I've got gear pullers, but the inside of the bobbin (wear sleave..) has a rounded flange on the outer rim, meaning the pullers have nothing to snag, they just ride over the flange and pop off! I've tried applying some small heat and also pulling it with soft face grips, but it really is stuck fast and I don't want to over do the heating in case of really screwing it up. Has the wear sleeve got a smooth internal bore or is in a fixed rotation? Are there wear sleeves available anywhere? I think this may be the route cause of it eating crank seals. Thanks again Mick Quote Link to comment Share on other sites More sharing options...
insultaco Posted January 15, 2012 Author Report Share Posted January 15, 2012 I think the O ring must have been put on the outside of the wear sleeve by my mate who fitted them last time. Or they have migrated from inside the sleeve to the outside. Either way, I think they are the glue that is holding it together. Quote Link to comment Share on other sites More sharing options...
naichuff Posted January 15, 2012 Report Share Posted January 15, 2012 Itis just a push on fit straight shaft Thereis two lenths depending if your motor has one or two drive side bearings my 175 has the short one but had an older 250 it had a longer one enquire at In Motion a site sponcer Quote Link to comment Share on other sites More sharing options...
pschrauber Posted January 15, 2012 Report Share Posted January 15, 2012 If your gear puller is fitted with an additional joint it is nearly impossible, If you have a puller with straight arms mounted to a rectangle arm where they can be fixed in a adjustable position it should work as it stucks normally not very much? May just a little bit of heat or better warming up to get the rubber soft and then turning with a good plier on the edge not the surface for the oil seal? To the part itself, may be Bultaco UK have them, if not Orlando Calonder should have them, or just refabrication, not a so difficult part to reproduce as it is round and you "only" need a lathe. Quote Link to comment Share on other sites More sharing options...
rhinouk Posted January 15, 2012 Report Share Posted January 15, 2012 Hi and thanks for the replies! I've got gear pullers, but the inside of the bobbin (wear sleave..) has a rounded flange on the outer rim, meaning the pullers have nothing to snag, they just ride over the flange and pop off! I've tried applying some small heat and also pulling it with soft face grips, but it really is stuck fast and I don't want to over do the heating in case of really screwing it up. Has the wear sleeve got a smooth internal bore or is in a fixed rotation? Are there wear sleeves available anywhere? I think this may be the route cause of it eating crank seals. Thanks again Mick Quote Link to comment Share on other sites More sharing options...
rhinouk Posted January 15, 2012 Report Share Posted January 15, 2012 Hi i recently had the same problem on my 151 tried pully extractor etc it would not budge,so took it to local garage who have gas welding kit ran the torch around for only a few seconds and it fell off. Regards Gary Quote Link to comment Share on other sites More sharing options...
b40rt Posted January 15, 2012 Report Share Posted January 15, 2012 If you have a puller with straight arms mounted to a rectangle arm where they can be fixed in a adjustable position it should work as it stucks normally not very much? This type I think ? http://www.google.co.uk/products/catalog?q=steering+wheel+puller&hl=en&safe=off&rls=com.microsoft:en-US:%7Breferrer:source%3F%7D&rlz=1I7GPEA_en&prmd=imvns&bav=on.2,or.r_gc.r_pw.,cf.osb&biw=1280&bih=933&um=1&ie=UTF-8&tbm=shop&cid=9827572766606814572&sa=X&ei=fyQTT6S9Jsuc-wbg-7njAQ&ved=0CF0Q8wIwAA Quote Link to comment Share on other sites More sharing options...
pschrauber Posted January 15, 2012 Report Share Posted January 15, 2012 Yes this is one I believe, I'am not so familiar with the brand, there are different puller models available, here some others that also will do the job without arms popping off, this one is very study and helpful also in other situations: This one would do the job getting off any smaller bushes or bobbings from axles too: Quote Link to comment Share on other sites More sharing options...
insultaco Posted January 15, 2012 Author Report Share Posted January 15, 2012 I'm looking at one of these, coupled to my existing pull jig should do the job, Quote Link to comment Share on other sites More sharing options...
john collins Posted January 16, 2012 Report Share Posted January 16, 2012 Hi Insultaco Everyone has given you correct advice re sleeve and seals etc Quote Link to comment Share on other sites More sharing options...
insultaco Posted January 21, 2012 Author Report Share Posted January 21, 2012 I'm looking at one of these, coupled to my existing pull jig should do the job, Quote Link to comment Share on other sites More sharing options...
insultaco Posted March 9, 2012 Author Report Share Posted March 9, 2012 Hello all My problem repeated (and has been a constant problem since my original purchase), even with the new wear sleeve, the bike chewed the new O ring up and it started with all the symptoms of blown seals again. I stripped it down again (now able to do blind fold) and started re-assembly. While I was doing this, I noticed that the gaskets on the inside of the crank seal baskets were well used, so I contacted BultacoUK for a new pair. The bike had arrived with me 15 months ago as a none starter and no matter what I replaced, renovated, twiddled or buggered about with, I kept having this same old problem with knackered seals and the stuck wear sleeve described earlier in this thread. When I got the bike it had gaskets on the left and the right beneath the crank seal retainers and also had the two sets of O rings left and right. When I ordered the full gasket set I got new everything I needed for the complete engine with a couple of extra bits, as normal when you buy generic gasket kits and so on I went with the re-build and re-re-build and re-re-re-build The guys at Bultacouk are very knowledgable (like many of you people reading this I have to also state) and when I asked for the new gaskets described above as a one off order, they quite rightly explained that my model didn't have any! I THINK this is what has been my problem all along, I've been repeating the same mistake made by previous owner(s) who have twice sold it on as a none runner. The gap of around 1/4-1/2mm created by the gasket on the right hand side where the sleeve sits has been preventing a full seal when the wear sleeve is compressed around the inner O ring. I think the hot gasses from the crank bearings have been getting in to the O ring therefore welding it on to the crank with the melted rubber and this has been causing the constant blown seals and stuck wear sleeve. Time will tell, but this is a lesson on reading things like the manuals carefully and not taking anything you find for granted! If this is what my problem has been all along, then they have been a very expensive set of gaskets that I shouldn't have had on in the first place! Cheers Mick Quote Link to comment Share on other sites More sharing options...
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