Newbie questions

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Philsbikes

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Hi all, I have recently acquired a Laverda 750SF, from the frame and engine numbers it appears to be a SF3. It was stripped about 20 years ago and left in a workshop in Spain so its not too bad rust wise, I have now got the top off the motor and that all looks good apart from the cam :(

Ok from the problems I have found so far my questions (the first of many im sure ;)) are;

Both wheels are damaged, has anybody ever swapped wheels with something more modern? Or anything else which I stand a chance of being able to get hold of without a mortgage!

Also are cams and followers a know issue, the bike has 40k kms so not too many, one of the inlet cams and followers is really worn and the they all look a bit rough, I still havent managed to remove the cam yet for a full inspection.

Lastly, on the frame there appears to have been some bracket of brace that has been cut off just below the fear of the tank, it is showing on both down tubes to the swinging arm area. Any ideas?

Thanks for the help and any advise.
Phil
 
Hi Phil, take a look at SunRims. They offer a wide variety of Aluminum rims, US made, as well as spokes.  There should be a small bracket with a captive nut on each downtube to which the sidecovers attach. the one on the left side also allows attachment of the fuse box. If you haven't one already, get a copy of Parker's Green Book. Lots of information and photos. Dennis 
 
Hi Phil, on early motors at least oil supply to the head is iffy at low speeds, such as idling in traffic, so regardless I would fit a new pump.  Most available now are SFC spec. or larger.  There are very fine oil drillings in the rockers to direct oil at the cam lobe, these become blocked very easily.  If the rocker shafts and/or bushes are quite worn this will also reduce the amount of oil getting to the cam - new shafts and bushes are readily available if needed.  I can look up the wear limits for these parts if necessary.  Also check the gasket face on the top of the head around the oil channels that feed from the front studs to the rear rocker shafts.  This can be damaged by butchers hammering the cams in or out, and could cause loss of oil pressure to the valve gear. 
 
With it being a SF3, it will have cast wheels....

Check out mid-80s Suzuki GSXR 18" wheels.

I've fitted these to several triples with great success and am about to do a twin this winter.  Allows running tubeless tyres in complete safety, increases tyre choice a bit and saves a lot of weight.  Serious brake upgrade also possible at the same time without busting the bank.

Cams and rockers are the first to go when maintenence is neglegted..... correct oil and a bit of care will see both through many miles.

Air filter lugs been chopped off?

piet
 

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Hello Phil and welcome as a new old twin owner.
I went through the mill with cams and followers many years ago. In my case it turned out that the rear (inlet side) studs were being held forward by the top cover. In fact when I tried to fit the cover with a 1mm wire in front of the stud to create a gap for the oil to get down to the rocker pin, follower and cam it was impossible to fit the cover. No oil type or oil pump size could have helped in that case. I elongated the holes in the top cover and to this day run a length of 1mm wire across the head through the channel with 10mm bent down the stud holes so that they cannot be blocked like this. I polish the cams and followers on the rare occasion I have them out. The same followers are still in the bike today. Small std oil pump and good oil.
These are pretty expensive parts so it is wise to check everything that can hinder the oil flow there.
It sounds like you will need a new/refurbished cam. Make sure the collars that connect the cam to the sprocket are a very tight fit. If they press on lightly replace them with undersize items as available from A. Wagner (and maybe others). If they loosen the keyway can snap and ....
You don't mention what damage the wheels have or if they are cast or wire.
The brackets could be from the air filter as Piet says or the regulator has been moved and it's lugs just behind and above the carbs removed.
 
How bad are the wheels?  I had both of the wheels ('softest ever' apparently) on my 180 straightened without any problems at reasonasble cost by Roy Thersby here in the UK.

Reggie
 
Thanks for the info guys, I guess it could be air filter brackets that have been removed, its the right sort of area, has anybody got a photo of a frame with them intact?
Regarding the wheels, yes they are alloy, the rear one actually had cracked on the damaged area, the front one is flat on one side of the rim, repair is an option but as I fancy trying to make this bike a bit different then other wheels would be my choice. I thought I had read about somebody modifying Yamaha wheels, they are alloy with discs all round on RD400's??

the cam is shot but the rocker spindles are still tight, I guess I will need another cam so what should I use, is there an "upgrade".

Thanks again,
Phil
 
Philsbikes said:
Regarding the wheels, yes they are alloy, the rear one actually had cracked on the damaged area, the front one is flat on one side of the rim, repair is an option but as I fancy trying to make this bike a bit different then other wheels would be my choice. I thought I had read about somebody modifying Yamaha wheels, they are alloy with discs all round on RD400's??
Click to expand...

Phil,

Using RD wheels might be one of the absolute cheapest options, but they are even narrower than the stock rims, 1.85 front, 2.15 rear iIrc.  And they are bloody heavy, the japs called the stuff "malleable iron" instead of light alloy!  Mucked around with RDs and the like quite a bit in my mis-spent youth....

I'm sure there are several more on board here that can vouch for the gixxer wheels.... it's been done quite often and works extremely well.  Doesn't make your bike a modern crotch rocket, but it will transform the bike like you wouldn't believe.

piet
 
Thanks Piet, I must admit to not thinking about sizes :-[, not a good start to my Laverda ownership... seriously though, I am trying to be lazy, how to make my SF just a bit different to the rest, its certainly different to my other bikes, probably rides better than my 79 CBX thats for sure.

Phil
 
Now this is an engine, damn sight lighter than the SF lump....
 

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When the CBX Thous came out I remember seeing a bloke Production Racing one at Darley Moor, frightened me to death and I was just watching, never mind having his hands full he probably had his trousers full too. :o
 
Fantastic pics Scrumpy. You blokes in UK have all the fun.
CBX first race in the world was Calder Park Melbourne in the wet 2 hour production race (or so they said at the time). Mick Cole won on that skinny tyred, skinny forked, overweight monster. Mick loved the bike even over the Roll a Door it replaced in the Honda team. They got something right with that CBX. A mate here occasionally races his Martin CBX in my class. Wins every time.
 
Agreed that the CBX motor is soooo pretty, mine has been a labour of love over 3 years, that picture is before a recent full engine strip, whilst it was down I vapour blasted all the cases and did alot of zinc work, she is looking really pretty now. I currently looking for another frame so I can do some wheel mods on it with CBR600 forks, and wheels.

Still looking for some frame pictures to see what my cut off brackets are, better go back to Laverda talk......


Phil
 
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