Laverda 500, 1979 starting / running problem

I

Istvan

New member
Location
Germany
Hello guys,

I am Istvan from Germany and I am new here. Happy to read your discussions and all the info about the Laverda bikes.
I love those bikes and recently bought a 1000 Jota (180) and short before, a 500 (year 1979).
I love repairing and discovering old bikes...and now it is my turn with the 500🙂👍

I bought the bike from someone, where it stays since like 25-30 years...but in a warm garage. Not rusty (except the Tank, which I already renewed) and the engine turned when II bought.
I removed the carbs, took them into parts, cleaned them and renewed all joints and what was necessary. Bought a new battery...and wanted to start... I checked and the sparks were working.
So...it did not start first. Even with a starter spray directly into the carbs from behind. Compression on almost 11....very good I guess.
After long trying...it starts sometimes with or without Choke and runs without any strange noise...between 2000-3500rpm. I let it lower...it dies. After sometimes starts...or not. While running, after maybe 1-2 min, it starts to backfire through the carbs (air filter tubes not on) or through the exhaust pipes.
No chance for iddle and normal start. What I should have a look for? I just bought new spark plugs...I will try.
Do you know that the air-Mix screw is 1,5 or 3 complete turns out? I read both....
Anyone some tipps or idea what the prb could be?

Thx a lot guys!


Istvan
 
Before delving much further it would pay to check that everything between the carburettors and the head is sealed and no chance of sucking in false air, which your symptom could well be. Manifold sealing to head and insulators, any vacuum type hoses if it has them.
The mixture screws work between about half a turn out (leanest) and about three turns out (richest), try richer, maybe two and a half to begin with, but where it wants to be when everything is correct can be quite individual between motors.
 
Check the wiring from the ignition pick-up on the left side. The isolation getting old and hard. Parts will break out and will short circuiting.
Very often the problem. You see it behind the cover but often it is in the cable jacket.
 
Most likely the insulation on the wires from the pickups have deteriated The wires covered in green corrosion and shorting out on and off.
You will soon find out if you removed carefully some of the outer insulation.
 
You were right. Cable Isolation is completely gone on several spots. I did not find the pick ups new on the internet. Surely they are some aftermarket ones but how to find them? Probably some other more frequent motorbike models have the same...but which one? Do you have any idea how to find them easily?
 
Istvan said:
You were right. Cable Isolation is completely gone on several spots. I did not find the pick ups new on the internet. Surely they are some aftermarket ones but how to find them? Probably some other more frequent motorbike models have the same...but which one? Do you have any idea how to find them
Click to expand...
You can repair the pickup's. Cut the wires at around 1 1/2 cm from the pickup. Then soldeer new wires. With two component resin you can ‘glue ‘ the connection at the pickup.
Watch out, there is not much space.
When you are a bit handy it is doable.
 
I think Bevel Heaven sells a kit to do this, they supply wire that handles heat and oil in that kit. I guess someone here knows the spec of that wire.
 
Little time and patience with graduating sizes of heat shrink and you can achieve a great result.. cut the wires at the connector end, work your way down to pickups and refit new connector plug.. worked for me on the Formula..

:cool:
 
Thx a lot for All the answers and for your Support.
Before I start to try to repair them...I saw that the Pick Ups for the Ducati pantah 600 SL are the same. Somebody tried to put those on the Laverda already?
 
Istvan said:
Thx a lot for All the answers and for your Support.
Before I start to try to repair them...I saw that the Pick Ups for the Ducati pantah 600 SL are the same. Somebody tried to put those on the Laverda already?
Click to expand...
No problem, are the same. Also the quality off the wiring……
 
Istvan said:
You were right. Cable Isolation is completely gone on several spots. I did not find the pick ups new on the internet. Surely they are some aftermarket ones but how to find them? Probably some other more frequent motorbike models have the same...but which one? Do you have any idea how to find them easily?
Istvan said:
You were right. Cable Isolation is completely gone on several spots. I did not find the pick ups new on the internet. Surely they are some aftermarket ones but how to find them? Probably some other more frequent motorbike models have the same...but which one? Do you have any idea how to find them easily?
Click to expand...
Hi Istvan
Click to expand...
I just gave up on the original ignition totally and fitted a Saches ignition system
 
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