84 Aspy fuel starvation?

[royando]

Just purchased a 1984 Aspencade with 32,000 miles and been parked for 6 months. It is very difficult to start and random miss and bog on accel and even throttle. Drained gas tank and carbs, all appear clean. Tried seafoam. Inspected timing belts. Time to check the fuel pump so hear is my question:
Does the pump only run on demand?
Can you feel or hear the pump run?
Should it cycle when key is first turned on?
To run a flow test, do i need to remove the fake tank and short the relay?
Thanks for your help.

[Granpah]

Whoa!

I'd start simple: clogged fuel cap; clogged filter, before tearing the bike apart.

There's a tiny bee-bee (tiny ball bearing) -loaded positive pressure relief valve in the gas tank cap which if it stops moving and/or gets clogged can create a partial vacuum inside the tank, restricting gas flow. Of course, a clogged fuel filter does the same thing. Most fuel filters are transparent so yo can see if it looks cruddy. So far as the clogged fuel cap scenario goes, unscrew the cap and let it sit at the gas tank opening -- and if your engine now runs smoothly maybe that's it.

If the easy things to fix do not turn out to be the prolem, I guess you can proceed to check out the fuel pump, etc.

'Hope that's useful!

[admin]

The fuel pump only runs momentarily after the the coil fires, in essence to replenish used up fuel after the combustion cycle. Yes, you need to short the relay to have the pump run continuously.

[royando]

Fuel pump flow was good. Both left cylinders were missing at idle, touched exhaust pipes to tell. Pulles the carbs off, used carb spray in all float chambers, pulled main jets (were clear), pulled low jets and both lefts were pluged. Runs much better now.

[bluewing]

That's good news, it always makes you feel good when you solve a problem like that and your bike is running good after your work.

[bs175dths]

Great news, but it can't hurt to change the fuel and air filters. Although the fuel filter is opaque, it may still need replacing, Same with the air filter. Extensive reading at this site will show an air filter looks good, yet will cause the engine to run rich because, in fact, it is dirty and restrictive. Besides being cheap and easy to replace, changing the two filters will also give you peace of mind instead of causing you to slowly lose your mind.

Keep us posted.

-Ride On