750 SF Starter Clutch guidance.
- Thread starter alpinista
- Start date
1200ts
Hero member
- Location
- USA - Riverside CA
As for removal you need the Laverda puller. Although on my 750GT, hitting it with a rubber mallet usually will break the taper free. Also the nut is left hand thread. If it has not been serviced in a while, the plungers, springs and rollers will probably all need to be replaced. Sometimes the plungers and springs will be stuck in bloody tight! A light coating of thin grease before assembly and your good to go. Also I get rid of the rivets holding the plate on and replace with screws and nuts. And finally you need to take the starter clutch off and clean and re-grease as a normal part of maintenance. Don't wait for problems to happen.
Laverda SF
Hero member
The Biggest Problem with the 750SF Starter Clutch is the stupid Back Plate Rivets come loose causing the Back Plate to FLEX. The Dog's will rattle and destroy the Springs. The Dog's Pins are probably OK but you buy new Dogs and Springs from Wolfgang Hearter. Either Drill and Tap the Fly Wheel for Bolts or Mig Weld the Back Plat onto the Flywheel will solve the problem. I use an 80 SAE Moly-Kote as a lubricant.
The Back Plate or Cage as it is called has to be true and not excessively warped.
Guess we are all saying the same thing.
The Back Plate or Cage as it is called has to be true and not excessively warped.
Guess we are all saying the same thing.
chrissoz
Senior member
- Location
- Sydney, Australia
Also I belive you need to lock the drivetrain or use a rattle gun to get the LH nut off (at least I had to do this on mine!).
Where in the world are you?
Where in the world are you?
Laverda SF
Hero member
Yes the FlyWheel Nut is a Reverse Thread - Best to use an Impact Gun.
Change the Seals while your at it ;o)
Change the Seals while your at it ;o)
Tippie
Hero member
- Location
- Dr?bak, Norway
I have never yet had a nut that needed rattling off. A good tap on the socket bar against compression with my trusty nylon mallet has always done it, I do the reverse for refitting it and have never had one come loose. To get the taper free I just give a quick stab of the starter to engage it and it has always jumped loose for me, but this does require it to grab.
From my experience the oilier and greasier it is the more prone it is to slipping, as it is exposed to moisture.
Over time the freewheel also gets pretty chopped around where the rollers engage. Does anyone refurbish these with hard spray-weld or bearing sleeve?
As 1200TS says, give it a going over as part of maintenance, or a first sign of slipping and have a set of springs handy. The springs break and then the rollers are loose.
From my experience the oilier and greasier it is the more prone it is to slipping, as it is exposed to moisture.
Over time the freewheel also gets pretty chopped around where the rollers engage. Does anyone refurbish these with hard spray-weld or bearing sleeve?
As 1200TS says, give it a going over as part of maintenance, or a first sign of slipping and have a set of springs handy. The springs break and then the rollers are loose.
phil37
Hero member
- Location
- Lincolnshire
Hi Tippie - About 20 years ago I fitted a needle roller inner ring to my s/m sprocket - also did a couple of small arc welds to retain it to the sprocket to make sure it doesn't slip around the thinner annulus that it was shrunk onto. Has worked fine and shows no sign of ever wearing out - I seem to remember that I had to surface grind the I/R down as I couldn't get one narrow enough from a bearing shop. - Regards - Phil
alpinista
New member
By way of an update. Had a couple of hours spare on Sat to make a start.
The cage, rollers and plungers are all in very good order, 5 of the 6 springs were around half their original length. Is it just me, or has anyone else noticed that they are the same length and diameter as the springs from a ball-point pen?
Raided the office, fitted 6 new springs, re-assembly nearly complete. Will get back to it tonight. I haven't welded or bolted the cage, as the rivets looked fine and the back plate was perfectly true.
Pete.
The cage, rollers and plungers are all in very good order, 5 of the 6 springs were around half their original length. Is it just me, or has anyone else noticed that they are the same length and diameter as the springs from a ball-point pen?
Raided the office, fitted 6 new springs, re-assembly nearly complete. Will get back to it tonight. I haven't welded or bolted the cage, as the rivets looked fine and the back plate was perfectly true.
Pete.
L
lemonjelly
Guest
bit late now Pete but seeing you are up road,remember I am now the Keeper of the ILOC tool library of which there are implements for 750s 
Dellortoman
Hero member
- Location
- Tasmania, Australia
alpinista said:
I've heard it said that size doesn't matter. It's how you use it that counts.
To some extent that's also true of springs. If it fits in the hole, the spring rate is more important than the length (which can be compensated for).
Ball-point pen springs are typically fairly piss-weak little affairs, so pale and weedy clerical types with asthma can click them. You may find you need something with a bit more testosterone for your starter clutch.
Simonr501
Hero member
- Location
- Lympne, Kent. UK
As a general rule do NOT let grease near the clutch rollers, maybe some light oil.
It is after all a device that slips in one direction but hopefully grips in the other.
It is after all a device that slips in one direction but hopefully grips in the other.
alpinista
New member
Simon,
I just used light dry lube for the rollers.
The spring rate seemed pretty similar to me during my 'exhaustive testing procedures'. On springs that small I can't imagine that it can be too critical, as you would be measuring the compression rate in grammes. Length and diameter are probably more important, ahem!
Thanks Shaun, everything came apart without the need for the special surgical instruments. Good to know they are just down the road, is free delivery included?
I just used light dry lube for the rollers.
The spring rate seemed pretty similar to me during my 'exhaustive testing procedures'. On springs that small I can't imagine that it can be too critical, as you would be measuring the compression rate in grammes. Length and diameter are probably more important, ahem!
Thanks Shaun, everything came apart without the need for the special surgical instruments. Good to know they are just down the road, is free delivery included?
L
lemonjelly
Guest
of course!
CV next Tues?
CV next Tues?
Been using general purpose grease on my starter clutches for near 25 years. Use it generously, the excess will centrifuge off at the first push of the button and then it'll be a zillion starts before you need to get back in there.
Have used margarine as a roadside repair on the SFC, works fine.
Ciao
Paul
Have used margarine as a roadside repair on the SFC, works fine.
Ciao
Paul
Simonr501
Hero member
- Location
- Lympne, Kent. UK
General purpose may well be ok as it does not have PTFE, Molybdenum or extreme pressure additives.
Try and think how the clutch works, it needs a small amount of friction to reverse the rollers and drive. If superior lubricant is used the clutch may slip.
I will insert a quote from a Sprag Clutch manufacturer:
'Sprag clutches may be oil or grease lubricated. Most sprag clutch manufacturers do not allow the use of lubricants containing extreme pressure additives'.
Try and think how the clutch works, it needs a small amount of friction to reverse the rollers and drive. If superior lubricant is used the clutch may slip.
I will insert a quote from a Sprag Clutch manufacturer:
'Sprag clutches may be oil or grease lubricated. Most sprag clutch manufacturers do not allow the use of lubricants containing extreme pressure additives'.