'75 won't start after running for a minute

[ChuckSeders]

Hi all - new here.

I've been slowly rehabbing my dad's old bike (1975 GL1000) which hasn't been started in at least five years.

So far: new timing belts, carburetor rebuild with Randakk's O-ring/gasket kit, valves adjusted, new fuel lines/fuel filter, Dyna electronic ignition installed, oil changed, new battery.

Just finished the electronic ignition today and it started and ran for a minute and a half (to my surprise - wish I could share the video) with some attending to the choke as it idled from around 1000 to 3000 a little sporadically. Since then I haven't been able to get it to fire. I rechecked the timing and 3/4 are spot on while 1/2 are a little early (which I can't get to delay any further due to the right-side module being turned to the max). Idle mix screws are set to 1 and 3/8ths from bottom.

What am I missing??
Thanks for any tips.

[MattMcCoy]

I would check to see if there’s spark at the plugs, inspect fuses, and then try to get it to fire with starting fluid if those check out. Could help point to either electrical or fuel issues for troubleshooting.

[ChuckSeders]

Thanks Matt - I should have written that all plugs have a good spark and it will run on starting fluid. I'll take a look to see if any fuses look bad though. I think I'm dealing with fuel issues, just hate to think I may have to pull the carbs again.

[MattMcCoy]

No worries. If it runs on starting fluid, it’s likely a fuel issue to chase down. Have you checked the fuel pump yet?

[ChuckSeders]

The fuel pump was my next target. Haven't opened it up yet as I haven't found much on what to expect or possible problems. I do see that each float bowl has fuel when I open the drain plugs. Maybe that's just gravity and the pump is still bad?

[MattMcCoy]

Here you go:

viewtopic.php?p=95266#p95266

[ChuckSeders]

Well I attached a tube to the pump output today and after turning the petcock back on I had a good amount of (really rusty) gas start draining by gravity. I figured right away that this has been pushed into the carbs which I'll have to remove and clean again, but I turned it over a couple times to see if it would pump. It did, but still full of rust. I opened it up and I'd say she's due for replacement.

[ChuckSeders]

To close the loop, I ordered and installed a new fuel pump after taking the carbs back off and cleaning them again. Luckily the internal screens caught the crap that was pumped in and they didn't need a complete breakdown.

Ran it for the first time in 5 years tonight. Runs like a dream.

Thanks for the pointers!

[Docketdog]

I had the same problem with my 1975 GL1000. The fuel filter kept filling up with rust from the tank. My solution was to use a battery charger and Arm and Hammer Washing Soda (sodium carbonate) to remove the rust and seal the tank using electrolysis rust removal. First drain the gas out of your tank, mix 2 cups of washing soda and 4 gallows of water. pour into tank top off with water. Next put a 3/4 inch PVC caped pipe with holes drilled in the side into the gas tank. put a length of REBAR inside the PVC pipe. Attach the positive lead to the REBAR...negative to the tank metal. The liquid in the tank will start to make tiny bubbles and the rust will be drawn to the positive lead. After 2 days the rust will be removed and the gas tank will be RESEALED from the electrolysis. Flush the rusty water out of the tank and you are good to go....!

[ChuckSeders]

Thanks for explaining that process. This tank was removed and sealed some years ago so I'm confident it's in good shape. But that pump was in bad shape.

Still, this information may come in handy on a future project.