davdeborg Posted July 20, 2013 Report Share Posted July 20, 2013 hi just done service and change my oils on my 151 325 Sherpa replaced the oil in clutch with atf as suggested and used by many now when I go to start it and kick over 9 times out of 10 clutch slips so engine wont fire up is it the oil ? clutch all adjusted ok and pulls like a train when riding with no sign of clutch slip only up on starting any suggestions or any one else experienced this using atf any help appreciated cheers Quote Link to comment Share on other sites More sharing options...
bondy Posted July 20, 2013 Report Share Posted July 20, 2013 hello no cant see it being the oil mate. when ive had this problem its usaly the clutch needs ajusting. have you ajusted anything? or it could have nothing to do with the clutch it could be the woodruff key on the magneto or the 1 on the clutch side i had the same problem not long ago i to thought it was the clutch tunes out the clutch weight woodruff key had shearerd just has you say kept sliping so before you do anying rash just first check the 1 on the magneto first if its ok check the clutch side if thats ok then turn to the clutch plates check there not worn or check that the littel throw out ball is in. it wont be 2 hard to short. cheers bondy. Quote Link to comment Share on other sites More sharing options...
davdeborg Posted July 20, 2013 Author Report Share Posted July 20, 2013 magneto key all good I know that for sure as just done points and condenser . wheres the woodruff key clutch side the basket fits on it ? and where is throw out ball? all I done was adjusted clutch un done big nut and unscrewed centre of clutch quarter of turn it did slip now and again about 1 in 20 now its everytime just started it and it slipped 6 times before starting on 7th kick cheers Quote Link to comment Share on other sites More sharing options...
p@ul250 Posted July 20, 2013 Report Share Posted July 20, 2013 (edited) Hi Davdeborg ATF is fine in your Bultaco. Make sure the clutch is adjusted properly I.E slack off the cable. open up the clutch access plug and undo the lock nut, screw in the adjuster until you feel it touch down, back adjuster screw out about a quarter turn and then tighten lock nut. Adjust cable's slack at handle bar. If the clutch still slips a new set of clutch springs from Bultaco UK may be called for (£12.00 a set) or one of their excellent clutch kits with modern style friction plates(£85.00) I know it sounds a lot but it really transforms the bike. After all your Bulto is about 40 years old and I bet the spring's are the original one's I have one of these clutch kits on my sidecar outfit and before I fitted it I hated having to slip the clutch (something we need to do a lot with a sidecar) I always got finger pump and half way through a section the clutch would be grabbing and totally unpredictable. Now it is a joy to ride and my 12 year old girl can pull it in! Edited July 20, 2013 by p@ul250 Quote Link to comment Share on other sites More sharing options...
davdeborg Posted July 20, 2013 Author Report Share Posted July 20, 2013 think its needed mate just stripped clutch and plates badly worn they are quite slick you can only just make out a few of the dots on them on some plates you cant see any. just put back together and mixed plates up and its a lot better but I know I need to spend out soon . I only ride for fun so not like riding trials every week I have looked at those kits on inmotion that's the way I will go but cant find spring compresser hard work with pliers and the wife pulling pins out with pin nosed cheers 1 Quote Link to comment Share on other sites More sharing options...
boghopper350 Posted July 20, 2013 Report Share Posted July 20, 2013 If it's ok when you're riding it should be ok when you start it. I know my 199a has a lot of compression and is a bit tricky to kick over. Is it slightly better when it's warm? ( if you can start it) I sometimes pull the clutch in and prod the kickstart when it slips, then try again (seems to help for me, I don't know why) Or just try backing the adjusters off a tiny bit. Quote Link to comment Share on other sites More sharing options...
davdeborg Posted July 20, 2013 Author Report Share Posted July 20, 2013 yes mate its better when warm just does my head in slipping all time trying to start and yes I got very good compression . and she pulls well in every gear cheers Quote Link to comment Share on other sites More sharing options...
guys Posted July 20, 2013 Report Share Posted July 20, 2013 think its needed mate just stripped clutch and plates badly worn they are quite slick you can only just make out a few of the dots on them on some plates you cant see any. just put back together and mixed plates up and its a lot better but I know I need to spend out soon . I only ride for fun so not like riding trials every week I have looked at those kits on inmotion that's the way I will go but cant find spring compresser hard work with pliers and the wife pulling pins out with pin nosed cheers Here are some pictures of a home made spring compressor: http://www.trialscentral.com/forums/gallery/album/168-bultaco-clutch-spring-compressor/ I had the same problem: the clutch slipped to hard when kickstarting so it would not start. And when it finaly started after a half hour kicking it would ride fine without the clutch slipping. I had mounted the new type clutch plates kit, but I had to put 2mm thick shims under the clutch springs and now it starts fine... Quote Link to comment Share on other sites More sharing options...
p@ul250 Posted July 20, 2013 Report Share Posted July 20, 2013 I made a simple clutch spring compressor from a piece of 12 mm O/D tube and a piece of plate. Cut a slot in one end of the tube to clear the pins, weld piece of plate to other end. with this against my chest/gut i could compress the spring and still have hands free. Quote Link to comment Share on other sites More sharing options...
davdeborg Posted July 20, 2013 Author Report Share Posted July 20, 2013 is it true that the clutch plates are the same for all models as I have just been offered a set of new old stock plates from a 1968 t 250 although my bike is a t 350 I know my crank cases are the same as a 250 cheers 1 Quote Link to comment Share on other sites More sharing options...
bondy Posted July 20, 2013 Report Share Posted July 20, 2013 yes i agree with the coments my plates where worn but it wasnt that i did buy the friction plates new but got them abit cheaper on ebay havant put them in yet as the bike is ok now it was the woodruff key on my clutch side had sheared off. you aske where it was on the clutch side its behinde the weight you have to take the clutch basket off this comes off at the same time as the weight its abit tricky. but easy after a few gose. the thro out ball is behind the clutch plates you only need to take the front plate off the clutch then you will see the mushroom take this out and its behind it may need a magnetic screwdriver to get it out are take the magneto case off and push it out with the push rod cheers bondy. Quote Link to comment Share on other sites More sharing options...
woody Posted July 20, 2013 Report Share Posted July 20, 2013 Clutch plates from the 250 will fit your bike yes, they're the same. It's not unusual at all for the Bultaco clutch to slip on the kickstart. They can do it with brand new plates, so fitting a new clutch won't necessarily cure it. I have Barnett plates in mine which offer more bite than standard plates and it can still slip on the kickstart even with the clutch correctly adjusted - but never when riding. The kickstart gearing is high and the shaft is also high up on the engine. Also, the kickstart is angled quite a way forward because of the amount of rotation needed before it engages, so it generally means people stab and thrash at it when trying to start them. Once you're used to it, you'll find it doesn't slip nearly so often. Pull the clutch in and take the kickstart down to a position that your leg is comfortable with and so that you will be pushing straight down, rather than trying to move the kickstart backwards first. Let the clutch go and slowly push downwards until the piston gets to TDC which you can obviously feel by the compression. Now let the kickstart back up a couple of clicks on the ratchet, back to a position that feels as though you can just push straight down. Now just push firmly but don't thrash at it. It should turn the engine without slipping this way. If you just lash away at it, then it will slip, regardless of new plates and being correctly adjusted. The Sherpas can and often do, actually fire when your just fiddling for TDC, without actually trying to start it. Once you're used to it, you'll find it rarely slips. 1 Quote Link to comment Share on other sites More sharing options...
woody Posted July 20, 2013 Report Share Posted July 20, 2013 magneto key all good I know that for sure as just done points and condenser . wheres the woodruff key clutch side the basket fits on it ? and where is throw out ball? all I done was adjusted clutch un done big nut and unscrewed centre of clutch quarter of turn it did slip now and again about 1 in 20 now its everytime just started it and it slipped 6 times before starting on 7th kick cheers It is nothing to do with the woodruff key on the clutch as if that was sheared and the crank was spinning inside the clutch drive sprocket, you wouldn't be riding the bike either as it would have no drive from the crank through the clutch to the gearbox. As you've had a go at adjusting the clutch, you could have unknowingly made it worse, even though you turned the centre adjuster out. When you re-tighten the lock nut, you have to ensure that it doesn't turn the adjuster screw back in again - which it can and probably will do. If that happened you could have actually ended up with it screwed further in than when you started, which could be why your clutch slip is now worse than before. Ideally, what you need is a box spanner cut right down so that you can see to hold the slotted screw adjuster steady when you tighten the nut. Or, when you're used to doing it, you can finger tighten the nut and then just put the final turn on it with a spanner. It will still turn the centre adjuster but if you have set this slightly further out than you want it and can judge how much it will turn with the nut, it will tighten in the position you want. Box spanner is better though. Adjust the clutch again. See the previous post from P@ul250 but it's better to actually remove the cable both ends. Then move the clutch arm on the casing as far backwards as it will go (there should be some play in it, if it is solid and already as far back as it will go, it's definitely adjusted too much, so see latter part of this explanation) Assuming there is play, when you screw in the adjuster, watch the clutch arm. As soon as you see it move it means there is no slack between the adjuster, pushrod and arm. This is where Paul refers to it bottoming out. If you now try to move the clutch arm on the casing, you'll find it is solid. Now just back off the adjuster a little. Now try moving the clutch arm and there should be a few mm of play from fully backward position to where you feel it engage the pushrod. That's how it should be. Reconnect and adjust the cable. 1 Quote Link to comment Share on other sites More sharing options...
p@ul250 Posted July 21, 2013 Report Share Posted July 21, 2013 is it true that the clutch plates are the same for all models as I have just been offered a set of new old stock plates from a 1968 t 250 although my bike is a t 350 I know my crank cases are the same as a 250 cheers Yes they are the same. all models all years of trials and MX bikes Quote Link to comment Share on other sites More sharing options...
bondy Posted July 21, 2013 Report Share Posted July 21, 2013 hi woody yes i agree with what your saying about the woodruff key on the clutch side i was just pointing out that it could have been. this is what happend on 1 off my bults i couldnt understand why i just had it runing then when i whent to start it again it was just like the clutch was pulled in nothing was biting. so i took the clutch basket of and weight and there it was sheared key. Quote Link to comment Share on other sites More sharing options...
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