Carburetor VHB 30 or ignition problem

[Laverda SLO 750]

Hi.

Problem with ...

The engine starts right away if I put on the throttle it revs OK (in stand).

But when I am driving it it sims that the engine is struggles to work and the power is not there.

The next moment it works fine. It is anoying to drive so. Will have to see the carburetors (needle and jets).

The break contacts are new and the ignition was OK (Marked P/M and A - checked with stroboscope).

If I do the idle it is working fine in the range of 1300-1400 RPM, when I chage it to 1000-1100 RPM as it schould be the engine is dooing fine for a few seconds than it drops down to 700-800 RPM and gets off in next few second.

The carburetors are VHB 30 and are open (without air filter).

The mixture is more rich than lean.

It has not the original exhaust.

When I pull the choke lever when I drive nothing happens.

KR; Mitja

 

[1200ts]

Rebuild the carbs. Not just gaskets but the needle and its jet and the float valve. And the choke plungers.

Make sure all passage ways are clean and If you have an ultrasonic cleaner that would be great.

Set the float heights.

Are the carb slides worn out?

Do you have the correct size jets in the carb?

In what condition is the ignition advance mechanism. This is a part that never gets cleaned and lubed until it is worn out.

Replace spark plug wires, resistor plug caps and plugs.

Make sure the fuel cap vent is not plugged and the fuel taps are flowing properly.

If you use the choke lever and nothing happens, then either the carb choke circuit is plugged or you are running very lean already.