If you have a decent spark, then the next thing to try is the fuel system. Make sure it has some fresh fuel in the tank, the E5 variety, not old stuff which has sat in the tank for 10 years, make sure there’s no water in the bottom of the tank. Check the filters on the fuel taps to be sure you have a good flow from the tank.
After that, clean the carbs thoroughly. I prefer to strip them down and blow through all the jets, push a fine wire through any holes and drillings to get everything clean and clear. I prefer this method to ultrasonic cleaning, although that would be a good first cleaning method. Treat the bike to some new fuel lines as the old ones have probably gone hard.
You should be able to get any carb spares, gaskets etc that you may need from Eurocarb
Check the choke (cold start) circuit as the rubber tips on the bottom of the brass plungers could well need replacing.
I do not understand the choke on this bike. It’s a small lever on the left carb that just drops down as soon as you lift it up? Unless that is what it is supposed to do?
Tank was empty when I bought it and I put fresh fuel and some sea foam. I opened the carbs again and they were full of petrol and jets were cleaned again and brush inserted into all 3 holes.
I tried putting little petrol into spark plug holes but it didn’t make it start.
Check the air filter, they can get full of oil from the recirculation system. Make sure there’s good flow from the fuel tap, if not new taps with filters are only around a tenner each. Make sure you’ve got a decent spark.
The choke lever should stay on when you let go of it.
Lots of V50 and V35 parts are interchangeable so that may make it easier to find parts. Gutsibits are a good source of new and used parts.
There should be a choke on each carb, maybe the other one is on the inside. They should stay up, but often the nylon wears and the flick back down. Try removing them and carefully filing the flat a bit so they do stay in place.
Check the condition of the rubber seals on the ends. You can buy replacements if necessary.
Surely there must be a hole for the choke mechanism? Are the plugs getting wet? Have you checked the float levels?
I have never owned a v35, but I can’t imagine they ever made them with just one choke. Have a look in the parts book to see what was the original set up. You should find the parts book, workshop manual and user manual here
Have you checked the level of fuel in the carbs? If it is smelling of fuel, you may have too high a level in the float chamber.
Are the plugs getting wet after you have been trying to start it? Pull the plugs out and check the spark is still working after you have tried for a bit.
It might be time to delve a bit deeper, is the spark occurring at the right time, do a very basic check of the timing to make sure the left side points are connected to the left hand coil, then check the valves are opening and closing properly.
If you are in Surrey and need help, Baldricks workshop is in Leatherhead and there’s not much that he doesn’t know about old Guzzi’s. He would be able to get it running pretty soon.
If it starts on easy start down the plug and runs for a while, it would suggest that the ignition and timing is okay and the problem is that the carbs aren’t delivering the correct fuel/air mix.
Have you tried easy start up the carb inlets (open the throttles a bit so it can get into the engine)?
How good is the compression? A simple test to ensure valves are seating and rings are free is to put it in top gear on the centrestand and turn the back wheel to spin the motor against compression.
