Bad fuel pump?

[Guest Larry]

My 86 Venture Royale has 32000 miles and has been running excellent, but now it won't run at all except at a fast idle and that with the choke full on. Is this a bad fuel pump symptom? Thanks for any advice.

[k7mdl]

Generally if the engine continues running at higher RPMs and does not die, fuel flow to the carbs are not likely the problem. If it will not run at low RPM, more likely the carb itself is gunked up or other fault inside.

 

You can remove the hose from the fuel pump easily and test. There is a fuel filter behind it which is not easy to get at though you can shine a flshlight on it and gauge how gunked up it might be.

 

If you stil lthink fuel flow to the carbs might be an issue, an 86 likely has a fair amount of rust in the tank bottom by now and it could be clogging the screen in the tank (over the petcock), the hose to the filter, or the filter itself. The fuel pump tries to maintain pressure so pulling the outlet hose off and turning on the key (engine does not have to run) the pump should squirt fuel out merrily.

 

If flow is good at the pump, consider a pinched/collapsed hose. There is a wire support at the top back center of the carbs that squeezed my braided fuel line nearly shut. Opening up the support a bit cured that. This is a hard one to diagnose since disconnecting the hose means removing it from the support, thus masking that problem. Only draining the bowls over time or such can test that.

 

If that is not it, could be the carbs are gunked up and need cleaning. Other things like floats out of adjustment and deteriorated gaskets/plugs inside also.

 

I started out with the fuel hose test because that is easy to isolate before treating carb innards with cleaners or taking them apart and you mentions the fuel pump directly in your request.

 

- Mike

[GeorgeS]

Also, Remove hose from output of Petcock, and Drain the Tank, Be sure to drain it down to completly empty to get out any water, and sludge.

 

Also drain all 4 Carb bowls, each has a sepreate drain hose,

 

Get a can of SEA-FOAM, fuel system cleaner, run 1/2 can to about 1/2 tank gas, if you can get it running.

 

Drain the carbs again. Also, of course replace the fuel filter.

 

If you can get it going, run two complete tanks of fuel with 1 can of SEA Foam each tank,

 

then re-evaluate the situation:

[Guest Larry]

Also, Remove hose from output of Petcock, and Drain the Tank, Be sure to drain it down to completly empty to get out any water, and sludge.

 

Also drain all 4 Carb bowls, each has a sepreate drain hose,

 

Get a can of SEA-FOAM, fuel system cleaner, run 1/2 can to about 1/2 tank gas, if you can get it running.

 

Drain the carbs again. Also, of course replace the fuel filter.

 

If you can get it going, run two complete tanks of fuel with 1 can of SEA Foam each tank,

 

then re-evaluate the situation:

 

 

 

Thanks for the help. I will do as suggested and let you know the results.

[Guest Larry]

I followed all the advice offered and the bike is running much better. It still isn't idling quite right yet, but I am still on the first tank of gas. I expect it to improve more with the next round of cleaner in another tank. Thanks to all.

[GeorgeS]

I followed all the advice offered and the bike is running much better. It still isn't idling quite right yet, but I am still on the first tank of gas. I expect it to improve more with the next round of cleaner in another tank. Thanks to all.

 

Again, open each carb drain, one at a time. Ign ON, let the fuel pump run some fuel through Each carb. One at a time. Make sure you get about the same flow thru each drain.

 

Have you checked your " Idle Mix Adjustment Needle Valves " ?? Remove lead seal, on each carb, Screw out ( carefully ) needle valve on each carb. Clean the Fine Threads. Then re install to full closed, and open to 2 1/8 turns.

 

After a couple more tanks with SEA - FOAM, you will be ready to do a CARB SYNC proceedure. ( see service manual )