1984 Honda VF500 - Engine dies after a few miles

Hello to all,
This my first post
I have an issue with my 1984 Honda VF500. When starting the machine runs perfectly. After a few miles the engine dies and turns off. After a short break (2 min or so) the engine starts up again and runs for the next few miles. Torque and speed is perfect until the engine dies again.
Now I'm searching for the reason of this behavior. If anyone has an idea - I'm open for everything.
I got it fresh from the mechanic. One of the things he changed was the gasoline filter. Now I'm wondering if he put it in the wrong orientation. Must it be horizontally or vertically mounted?
English is not my native language, so if there is any confusion I'm happy to clear it up.

 

check for pinched or obstructed fuel lines
try to run it with the gas cap open - if it runs correctly one of the tank vents is blocked.
Make sure the fuel filter isnt in backwards, there should be an arrow showing the direction of flow

 

Thanks for the reply

I drove with the gas cap open - same problem. I will check the fuel lines and and fuel filter tomorrow. (It's night here.) Many thanks for the pointers.

 

It sounds like the carbs are getting some fuel but not enough to meet the demands of the bike at speed. This could indicate an issue with the fuel petcock or a partial blockage somewhere along the way. Have you checked the gas tank for signs of rust?? When the bike stalls you should also check to see if the fuel filter and fuel line into the carb is empty.

Rollin

 

^^^^ That's right: if your tank is putting out rust along with fuel, you can't depend upon any filter to stop the smallest bits.

 

I checked the orientation of the fuel filter - this was alright.
I checked the fuel flow today - I redid the air tube which is pumping the fuel out of the tank (the little tube in the middle of the attached pic)
I went for a test ride after that, but after 17 km (appr. 10 miles) the engine died again and didn't restart :censored: . I walked home 5 km (3 miles) and will take it to the mechanic this week since I don't have a clue what's happening. Let's hope it is starting tomorrow or the day after so I can drive it to the mechanic.

 

That 's an air vaccum line that opens a diaphram in the petcock, not supposed to see any fuel in that line.

You should test for sparks when bike goes kaput, cuz you might have defective pulse generators ( pick up coils), which might be working OK when cool but fail when heated up.

 

@squirrelman not seeing any fuel in this line - it just had a dent, but doesn't have a dent now. So this should work alright - fuel is pumping out of the filter when turning the starter motor on.

I checked for a clean spark plug so these should work - how can I check the pulse generator? Where can I see a spark if something isn't alright? Shouldn't the cockpit lights dim when a spark occurs since power is drawn?


It's a pity that it's not working, cause it's an awesome bike otherwise.

 

Pulse generators are checked with an ohmmeter at the connector plug.....exact figures are in shop manual, but usually run between about 300-500 ohms .


NONONO, lights don't dim .