VF700F issue after 15miles

Hi - I have a 1985 VF700F (Interceptor). It starts up and runs great, well, for about 15miles or so. Then it starts to run like it is starved for gas and dies. I can't restart it from the start switch, but have been able to pop-start it. However, it usually then runs rough (need to keep the RPM high to keep it running) and/or I need to run it with the choke full on. So, it seems like a gas issue (I'm going to replace the inline filter (paper filter) with a screen filter. I'm wondering if it could be a spark wire, coil, or CDI issue. What is the best way to debug it without getting a load of replacement parts? Sometimes it will start right up and run fine. Other times it will pop-start and run rough. It always runs fine after sitting and will start right up and go.

It is fun.... when it runs.

Thanks for any help/advice.
Randy

 

Check the spark plug wires for arc'ing and/or grounding to the engine block. If they are old or original, the insulation breaks down and they can ground right through the plastic caps or the wires themselves.

Less likely but possible, check the gas cap for venting.

 

Ok, I checked the tank to see if vacum was being created. When it started to die last time I unlocked the gas cap... no difference.

What I think is happening is that I'm simply using up the fuel in the carb bowls and whatever has dripped into them during the ride, then..... putt putt cough cough.... stop! There was a fuel shutoff installed in the fuel line when I got the bike. I suspected it was there for two reasons.... a bike with no gas flow is harder to ride off with and the petcock leaks in the 'off' position. I removed it and put in a paper filter. I did this before riding it so suspected that the paper filter was clogging and not allowing enough gas flow. So I put in an an in-line screen filter instead earlier this week.

I've riden the Interceptor twice now since then to the next town town.... 10 miles there. 10miles back. 19 of the total 20 of which I complete without having to push the bike. It is very consistant about stopping in the 19mile range. This leads me to believe is a fuel problem. Would an electrical problem be so consistent?

What do you think I should try next? Try to pull/check/clean the petcock? Take out the fuel filter altogether? Check the electronic fuel pump? Could it be electrical (plug wires, condensors, CDI) and yet be so consistent at 19miles?

By the way, I did ride it successfully on a longer trip *once*... I *think* it was after I pulled out the additional fuel shutoff valve and put in a filter. That was on a ride that was maybe 19miles *each way*... and it ran great! That is the only thing making me think it may be a non-fuel issue.... but *always* dying since then at that 19mile mark sure makes me think fuel.

Open to suggestions... thanks for any advice! Pushing a Honda is not as much fun as riding one!
Randy.

 

It "sounds like fuel " problem...try jumping your fuel pump ..

Also your starter switch problem sounds nasty familiar to a problem I had with mine...it eventually "back fed" the electrical system and blew all the lights out bypassing the fuses...... make sure yoiur switch is good....

start wwith a fresh battery or charge yours over night ..... and check voltage on your R/R it may be going out...

 

Two components that sometimes fail after engine reaches operating temp are pulse generators (pickup coils) and ignition coils, so do a test for sparks after the bike stalls.