Re: What did you do to or for or with your Laverda today?

Hi Cam,
Yes, a mechanic pal with shed up here in the 'ville has a few weeks off work so was interested to help me pull it apart to see what's what. On that basis I put it on a truck heading oop the North. Well, we've pulled it apart and, other than the few obvious symptoms of ill health on display at Bellingen, we haven't found anything really wrong with it. I suspect it was simply shy of crossing into NSW...

Valves look good (though had been running hot): seats look good. A little lapping to ensure a seal looks to be all that is required there. Barrels mic'd up within tolerance, pistons likewise. Will order new rings on Monday from JP Pistons. Head hadn't been torqued down and was essentially loose (though the seal at the flame ring spigots was good). At least one of the  shorter 9mm studs had 'pulled' so have ordered a Time-Sert kit to fix that (and others that may be a little suss).

Will hopefully have the head back together by Monday and the barrel/pistons by the end of the week. Assuming a head gasket and shims can be sourced the engine could be back in by end of the month after my help comes back off roster.. So far so good..

AndyW
 
To bee or not to bee, I suspect that's a Belingen bee stuck to the top right corner of the badge...OK I'll wash it today now that I've been for a ride.

dvDy5ill.jpg
 
Dellortoman said:
Ooh goody - a bodge!
Hmm ... what could it be? Cornflakes packet base gasket? Tips of valve stems filed down?
C'mon, lets hear about it so we can all pass judgement. :D
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<Drum beat.. Steps forward, shirt torn to the waist.. surveys the baying crowd (what a rabble!).. Slowly kneels and, reluctantly, places head on the block of wood and peers into the basket.. :o>

I was thinking of making some flame ring sized copper shims from thin sheet or thick foil (whatever's available).. and using one of the later style gaskets :-X.

There, now, Careful with that Axe Eugene... :D
 
The flame rings on the head gasket might look like copper, but they're steel. Stick a magnet on one if you don't believe me.

If you wanna make a set of copper shims, you'll have copper sandwiched between aluminium and steel. Chuck a bit of acid in there and you could use it as a battery!

You'd need the shim to be somewhere in the 0.1 to 0.3mm thickness range. It might work just fine. On the other hand, you mightr end up yanking the head off again to fix it. If it were me, I'd want to minimise the risk of having to pull the engine out again, so I'd go with a proper gasket. Those skinny ring gaskets are OK for barrels with 1200 liners, so someone will take it off your hands.

 
Hmm.. I was almost impressed there, Cam Douglas, however, I'm going to have to go with tosh 'bluff' on this occasion. I've just retrieved the original gasket from the depths of depravity (ie downstairs) to test with a magnet and, although the steel lined composite section is magnetic the 'copper coloured' flame ring (ie the copper bit) isn't  :D :D
 
OK, there must be a lot of different versions of head gaskets. The last couple I installed had steel flame rings. It was definitely magnetic, so I had a scratch at one of them and the thin copper veneer (copper plate?) came off to reveal steel underneath.
 
Dellortoman said:
OK, there must be a lot of different versions of head gaskets. The last couple I installed had steel flame rings. It was definitely magnetic, so I had a scratch at one of them and the thin copper veneer (copper plate?) came off to reveal steel underneath.
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Well, I'm referring to the 1974 version; the one which the flame ring starts off with a thickness of 1.3mm and which, 40 years later, is only 1.08mm (42thou?) thick. Now, magnetic or not, that's a lot of distortion if it's really steel and only 25 FtLbs of torque are applied to the head studs....

Just sayin..
 
OK. I'll have to eat my words. I just pulled a couple of old head gaskets out of the rubbish bin in the workshop, and they had copper rings. I'm beginning to doubt myself now, but I could have sworn the rings on the new gasket were steel. They were a silvery colour and magnetic.
 
I think you should pull your bike apart to check the gasket that's in there too..

How much for those old gaskets? I can feel another bit of experimentation coming on..
 
I dug out the SFC so I cn prepare it for the Geelong revival speed trials in  few weeks will have to gear her down a bit so I can get off the line  bit quicker, here she is next to 1402 "the hardest bike to tune in the world" :( :( :( :( :( :( :( :( :( :(
 

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rowdypat said:
Always flying the flag..........
Spot the tenuous Laverda connection
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was going to say that the chick in blue looks like she has just got off the back of your 750 and is suffering from vibration induced enjoyment but I believe it may have something to do with a certain stubby holder

 
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