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Montesa 348 .. Overtight Clutch Nut?


telboy1969
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I know its been a couple of months since I last posted but been mad busy at work so havent had time to play! The good news is that the old girl has taken shape and is looking like a trials bike again. Once fully complete i will post some pics of the restoration, next project is a ty80 restore so I'm learning all the time at the mo!

Back to the 348 though, the clutch did not work, nada, nothing, so got a replacement basket and plates off ebay for cheap money! fitted them today, the balancer nut had been loctited on so after lots of heat, rattle guns, long bars and grips it finally came away. Put the new (2nd hand) basket on, finger tightened the nut, fitted the casing back on to test and wahoo working clutch!! Took casing back off refitted the balancer and tightened both that nut and the clutch nut and put everything back together thinking I'd solved the problem but sadly no... pull the clutch and the kickstart goes floppy but put it into gear and the clutch does not work...

My conclusions are that it was working when finger tight, can't imagine the balancer is the culprit, and the only thing I've really done is tighten the clutch nut up to the hilt and bent over the tab washer so question is am I over tightening the clutch nut? should it be just past fingertight or have a torque setting? Or am I missing something obvious? All this has been done with the engine not running, so does the clutch need to be spinning to work properly. Any pointers would be greatly appreciated!

Finally, the seat base was rotten so have had to use this as a template and slowly build it up with fibreglass to the right shape, final piece of the jigsaw nearly done (apart from the clutch), got some VW mars red to respray the tank unit then its time to play ....hopefully!!

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when the clutch nut is finger tight the pressure plate is not in the same position relative to the spider fingers as it is when it is tightened. There is no point testing the clutch action with the nut finger tight. A common problem with those clutches is the fingers on the spider bend and wear. I would also check the button that pushes on the spider for wear or damage

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Just out of curiosity what is the part you are calling "a balancer"

The 348 and I believe a lot of other Montesas have a heavy additional flywheel attached to the end of the crankshaft on the clutch primary drive side of the engine.

They are keyed to the shaft and if not torqued up properly shake about, split the keyway and snap the crank shafts. They over hang the end of the crank by an inch or so. in hindsight and at 40 years old something of a timebomb.

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Thank you so much for the replies... had another play today , put in a brand new longer brass push pin and have nearly got a clutch back... real fine line though between it working and making the kickstart floppy so it won't kick over. will check the settings of the clutch nut with a torque wrench later this week when I get chance but my guess is that the nut is way over 15ft lbs so am betting that if I slacken that off and torque it correctly I might get a proper clutch ...

Does the manual say the torque settting for the balancer nut? I made that one very tight again as I don't want that to make an appearance out of the side of the casing, it was very very tough to get off so was guessing the tighter the better on that one...

Will let you all know how I get on but once again many thanks.

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telboy1969 I've had this issure before, for me the solution was the brass push pin that pushes the clutch. If you take it out and look at the back of the pin, you will see on one side it is slightly angled. This needs to go in the correct way round. From memory I think the cut out angle needs to face towards the primary. When it's put in the other way round it was sticking out a couple of mm too far which was causing the clucth to engage slightly and the kick start to slip. Hope that helps.

Also.. How many clutch plates did you out into your clutch? I'm in the process of changing mine, I took 13 plates out of the old clutch and I have 15 plates to go back in.

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I'm having the same 'classic' 348 clutch issues.

My Spider's tip-top, so is the (8mm) brass pusher; the clutch lever's been tweaked to give maximum travel / span, and I'm using 300ml of ATF.. but if I slacken the cable just enough for the kickstart, the bike creeps in gear- and finding neutral with the engine running is virtually impossible.

Having tried everything else, I've put a 10mm pusher in, but this has taken up all the cable slack. Fingers crossed!

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Hi Sam- TBH it's the one thing I didn't check. What's reckoned to be best?

As a Montesa newbie, I'm learning as I go- and finding my bike has a number of 349 parts fitted. The clutch cover is definitely a 349 one-piece type, so hopefully I won't have too much trouble ironing out the niggles.

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Right, hmmm the sodding clutch..... Thanks big shiney will check that today or tomorrow when I take the casing off yet again!! Will clamp it and see whether my torque wrench is up to the job.....Just to give you all an update, torqued the clutch nut to 20 newtons (just over 15lbs), have an old short pusher and a brand new 10mm one, and two of everything else including spiders, retaining pins, tab washers... the lot. I've come to the conclusion that the old pin is too short to work it and it would appear the 10mm is too long and just gives me a floppy kickstart, HOWEVER take the clutch out of the lever and I get compression back will just and so work without the handlebar adjuster, think I've spotted what may be the problem with it now though.... Up until now I've disconnected the lever and left it dangling to work on the clutch, when I came to put it on last time the nipple popped out and as I went to press it back in I saw that it wasn't a nipple but the end of a bolt with a hole drilled through and the wire soldered/welded/stuck/whatever into place!! Now its beginning to make a bit more sense.... the cable has obviously snapped at some point, probably near the nipple and someones done a repair which means of course that the clutch cable is that little bit shorter.... So when I try and put in the new 10mm push pin it presses the plates straight away hence kickstart slipping.... Probably my schoolboy error that I didn't spot this before, it never dawned on me, but logic now says that a new proper length cable and the 10mm may just work... will buy one and see, fingers crossed..

Samwisemcg, have 13 plates in both clutches, one set has side slots for the rattle springs and the other set look like aftermarket ones with no spring slots, definitely 13 though not 15, I'm guessing it ill be down to the thickness of the plates though so you'd have to stack them next to the old ones to see how much difference the 15 plates make. I'm also guessing you're changing them cos they're worn so would expect the new ones to be a slightly bigger pile at the right amount if thats logical...

Mind you what do I know about montesa clutches.....hahaha

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