Tappet spanner 750

BlackJota

BlackJota

Senior member
Location
Sunshine Coast Australia
This spanner was in a box of parts from the basket case 750 I bought back in 1980. It is stainless steel, has the exact
size square drive hole for the tappets, and is stamped Laverda on the handle. Works a treat, but i am questioning if
this was a factory special tool or a one off hand made. Cant imagine why someone back in the 70's would have gone to that much trouble to make one of these
spanners and stamp it Laverda for the odd tappet adjustment job. The square hole looks Punched, not drilled and filed.
 

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Setting tappets through that head Cap is not an easy task on the Breganzie 750.

I always preset the SOHC tappets during a rebuild, using a dial indicator, but did check the tappet clearance after some 500 miles with a feeler gauge.

Looks like that Wrench may work ?

Make sure the engine for a specific cylinder stroke is sitting on the cam heel when adjusting tappet clearances using a feeler gauge.

Like you, I always had to modify a spanner to reach in there - do not be afraid ;o)

Do NOT over torque the nut.

With some ingenuity you can mount a dial indicator through them caps to measure cam to lobe clearances.
 
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I have no idea about Laverda twins, but I made a special tool to do Triumph valve clearances. I welded a small lever on the correct sized socket with a hole down the middle that took an allen key. The Triumph thread type allowed it to use degrees of rotation for a distance. Checked after with a gauge. Way easier than juggling a couple of tools at once.
 
The original tool as supplied with the factory tool kit tool is much simpler, a straight piece of black painted steel with a 3.5mm square hole punched in each end. It's not the easiest to use, the example with angle may be better and I can imagine somebody with a 750 doing frequent checks was looking for a better tool and made that and stamped in Laverda so as to remember its purpose.
I have found it much easier with a tool similar to this as the inner tool while using an angled ring for the locknut (not endorsing this particular tool - check it fits and will work for you)
3.5mm tappet wrench
so there's more separation between the adjustment wrench and the locknut wrench and more space for fat hands.
It seems that 3.5mm square ends on the adjusters are also used on Japanese bikes of the era so similar tools are easily available.
 
+1 on the clock key! Excellent to use, at least for the OE adjusters. The commonly used replacements require fiddling...:(

piet
 
Dellortoman said:
I always thought the 750 twins had a bit of a ticking sound while idling. Now I know why - they're clockwork.
Click to expand...
The tick is usually caused by either of two things: 1. an OS gap (usually because the valve stem pits and becomes concave, so it's difficult to determine when the gap is to spec (which is why I fit Rotax elephant's foot tappet adjusters) or 2. small amount of lateral play in the rocker spindles (I carefully grind the shoulder on mine to ensure no excessive play).

But once done right, they run like clockwork - digital clockwork, Cam! Silenzio!
 
Easy to do when the engine isn't in the frame - A little more of a struggle with the engine in the frame - Yet a lot more easier then setting tappets on a Ducati Desmo which you have to check about every week so Vs the SF after setting tappets after a break in you really don't have to check them again for a year or 2 ;o)

I do recommend that you change your SF valve springs out about every 3 to 5 years pending how hard you ride her.
 
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Laverda SF said:
... setting tappets on a Ducati Desmo which you have to check about every week
Click to expand...
They're not that bad Ron. I check my Ducati MHR valve clearances every 10,000 km.
Last time they actually measured OK so I didn't bother adjusting them, which is a heads off job on a bevel twin to do them properly.
The opening clearances were within limits. Closing clearance of zero is not so easy to measure (I can't find my zero feeler gauge). I just waggle them to check that there's no loose clearance and that the compression is OK (if they're too tight it'll show as a drop in compression).
 
Just set the clearances on the 750, used needle nosed pliers, number 5 clock key is 3.5mm square. Available on ebay cheap as, will order one up, or is there a better tool available?
 
martymoose said:
Just set the clearances on the 750, used needle nosed pliers, number 5 clock key is 3.5mm square. Available on ebay cheap as, will order one up, or is there a better tool available?
Click to expand...
I ordered a clock key which is waiting in the workshop for its first use.

I'll never regret it I think. A great tip.

Paul
 
I used the clock key yesterday to set my tappets, great idea, really easy to hold the tappets in place whilst tightening the lock nut. Best specialist £2.50 tool I've ever brought.
The bikes not going anywhere soon, but that's a different story.
 
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