Laverda Tappet for SF1 1973

olly

Senior member
Has anyone got a single Laverda SF750 (SF1 - 1973) tappet please. I think the part number is 3049020274 shown on the diagram
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I'm told there's a vauxhall part that can be used instead - anyone know the part number please? or ideally anyone with a Laverda one spare. One of mine has some sort of weird decay and is badly pitted.
 
I'm told there's a vauxhall part that can be used instead - anyone know the part number please? or ideally anyone with a Laverda one spare. One of mine has some sort of weird decay and is badly pitted.
Have a close look at the tip of your valve/s. It's often both valve tip and adjuster that end up looking shite. A good reason why a lot of us have converted to Rotax adjusters - not a straight fit though and requires removal of the head and some minor surgery to rockers - but well worth it IMHO.
 
Have a close look at the tip of your valve/s. It's often both valve tip and adjuster that end up looking shite. A good reason why a lot of us have converted to Rotax adjusters - not a straight fit though and requires removal of the head and some minor surgery to rockers - but well worth it IMHO.
The valves new, the head is off so if I'm going to go down a non standard route then now's the time.
However.....
On the thick cast SF1 rockers I needed t grind a fair bit from the underside of the tappet end
You do need to shorten them a tad and possibly grind a little off the tip of the valve and maybe a tad from the underside of the rocker arms.
On the later rockers I had to relieve a mm or two from the underside and I also tipped off a mm or two from the valve tip. You can see what needs when you have it apart, but it wasn't a big job. IIRC the screws were pretty long and were cut off and a new square filed on for adjusting.
I had one of those elephant's foot adjusters let go ... found the centre inlet rocker had jumped the pushrod.
There seem to be at least two options as well
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With the captive half bearing design there will be no need to modify the rocker so are they preferable (they're cheaper). The Rotax style ones are £25 each.

Others are saying go with a mushroom head design though a quick Google doesn't find any with an M7 thread.

Heeeeeeeeeelp please :)
 
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25 quid is way too much - I'd try elsewhere. I think Marty's thread where we discussed this I mention the price (in Australia, from the Rotax importers, so they'd travelled a long way from Austria!). The SF1 rockers are pretty chunky, but taking a bit from the underside isn't a big deal - you basically want the pivot to operate without fouling on the underside of the rocker during full valve open-close and causing the flat to not remain flush on the valve tip - Marty will have the details - he did his recently.

Someone used a non-Rotax version and had it fail - the Rotax ones appear to be bulletproof.
 
 

25 quid is way too much - I'd try elsewhere. I think Marty's thread where we discussed this I mention the price (in Australia, from the Rotax importers, so they'd travelled a long way from Austria!).
They're even more from the Rotax importer here - over £35 each.
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Shaeza! That's not much less than you'd pay for a new valve! Wonder if it's a Brexit thing or maybe the Oz importer has tripled their price as well??
 
The valves new, the head is off so if I'm going to go down a non standard route then now's the time.
However.....




There seem to be at least two options as well
007088.gif

100_0616.jpg

With the captive half bearing design there will be no need to modify the rocker so are they preferable (they're cheaper). The Rotax style ones are £25 each.

Others are saying go with a mushroom head design though a quick Google doesn't find any with an M7 thread.

Heeeeeeeeeelp please :)
 
Olly, forget the overthink.. there are bound to be original parts available.. as Paul suggests.. and I suggest with a small wink..
You only need one.. if you were doing a full head rebuild, then this may be different in my view
Go for the best, original and available offered by long term friends..
Just my humble opinion..
 
... can anybody tell me from which ROTAX engine these valve adjusting screws are? Is it the single cylinder 4-stroke ROTAX KTM form the 80s? I have some good connections to ROTAX her in Austria ... Ciao, Gert
 
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Yes, the old Rotax single-cylinder, belt-driven OHC jobbie. Found in early KTMs, various MuZs, H-D/Armstrong, and certainly quite a few more.

If you could source some, I'd be interested as well!

piet
 
Olly, forget the overthink.. there are bound to be original parts available.. as Paul suggests.. and I suggest with a small wink..
You only need one.. if you were doing a full head rebuild, then this may be different in my view
Go for the best, original and available offered by long term friends..
Just my humble opinion..
Head is being "rebuilt" I put that in quotes because I cant quite remember exactly what's been done by Keith and Laverda Scotzia. In summary though - a lot.
 
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