V 50 III trouble shooting

[Pakirk53]

83 V 50 III had carbs gone through cleaned and sealed tank myself mechanic just went through carbs again and adjusted points but same symptoms. runs fine for 6 or less miles then acts likes it starving for gas stall and won't start again until it sits awhile and will run fine awhile then stall again

[lucian]

could be loosing spark on one side , when it dies pull both plugs, if they're wet it's not fuel. ground them on the heads and crank it over, checking for spark sounds like a bad coil.

[not-fishing]

My son and I resurrected a V50 III a year ago.  The first thing we did was a Dyna ignition, Dyna Coils and new spark plug wires. 

Also after rebuilding the carbs, clean & reseal the tank we cleaned the petcocks.

Mark

[Chuck in Indiana]

Check and make sure the fuel cap is venting.
Welcome to WG, BTW..

[Guzzi relic]

Tank venting is a possibility. If you can open the cap just as the problem starts to happen and see if this helps. I've had caps that the vent was plugged or not working.
Also, I've had a few points/condenser ignitions over the years that did exactly this due to a failing condenser. After a few minutes of cool down they would start and run for a while again. Eventually it fails totally and you have no spark. Then its much easier to diagnose.

Ken

EDIT- I guess Chuck and I were typing at the same time...

[pehayes]

Check and make sure the fuel cap is venting.
Welcome to WG, BTW..

PLUS ONE.  Loosen the fuel cap and drive around for awhile to see if it repeats.  A vacuum in the tank will prevent fuel from draining to the carbs.  Inspect all fuel lines for internal collapse.  Unscrew the filters from the side of each carb.  Turn on the fuel and watch.  Drain the fuel into a suitable can.  I should drain freely and continuously until the tank is empty.

Inspect the fuel filters at the side of the carbs.

Inspect the fuel filters residing on the inside top of the petcocks.

Patrick Hayes
Fremont CA

[Idontwantapickle]

acts likes it starving for gas

Probably is, clean out the petcocks, lines and screens but don't forget the gas cap either. My LeMans did this because of clogged tank vent in the cap. Not saying it can't be the ignition but your instinct is probably right. 

Hunter

Edit. I must be the slowest typist here!

[Diploman]

As others have suggested, your problem may be insufficient fuel flow from the tank.  That said, historically, the most frequent and severe problem with the V50III has been the points ignition, a cobbled-up affair retrogressing from the problem-free Bosch electronic ignition fitted to the V50 and V50II.  Cost-Cutting, undoubtedly.
The solution is to fit an electronic ignition.  In the US, the most frequent choice for this conversion has been the Dyna ignition, as suggested above.  Even if your problem turns out to be insufficient fuel tank venting, sooner or later (probably sooner) you will want to fit an electronic ignition to your bike.  The points ignition is simply too unstable and problematic for the long term.

[wrbix]

Failing coils

[Diploman]

What your bike needs:

http://www.mgcycle.com/index.php?main_page=product_info&cPath=37_157&products_id=2849

http://www.mgcycle.com/index.php?main_page=product_info&cPath=37_157&products_id=1598

[MMRanch]

I have been know to remove the fuel cap and shoot a shot from an air compressor up the fuel line to clean off the crud that stops-up the petcock filter material.
Or ya could just take the petcock off and clean it right  ??? 

I'll have to admit : my carbed bike has a special place in my life ! 

[Pakirk53]

Thanks for all suggestions it gives me some guidelines to pursue