Author Topic: fuel pump or fuel cut relay going bad? (Read 3164 times)

ranakin400 · « **on:** April 08, 2006, 09:31:45 PM »

This is actually for my honda cb1 400 bike (the the cb1 forum has been down for a while?).

I started it up and let it warm up. I noticed that the fuel pump was noisy and was ticking loudly like a typewriter.

I ride it halfway home when the bike dies on me. I ve never had a problem with my bike so it must have to do with the fuel pump or fuel cut relay.

I ve tried disconnecting a fuel line and the pump still shoots fuel. The bike wont start.

Can anyone help me diagnose this or do fuel pumps and relays go bad over time?

tomacGTi · « **Reply #1 on:** April 08, 2006, 09:42:36 PM »

Fuel pumps won't usually die completely, they'll usually have just enough ass to idle and that's it. Anything else will cause them to lurch and buck and just run like they're on 1/2 the amount of cylinders. They won't be able to cope with the added resistance of additional fuel load.

Fuel usually cools the armatures inside of a fuel pump so if you run it dry, you increase the chance to burn it out. That and old age as well.

-Randy

ranakin400 · « **Reply #2 on:** April 08, 2006, 10:20:26 PM »

So I should just buy a new fuel pump then? The ticking like a typewriter sound should be from the fuel cut relay malfunctioning?

tomacGTi · « **Reply #3 on:** April 08, 2006, 10:47:06 PM »

It could honestly be either, how many miles are on the thing? Did it start to do this gradually or all at once? After it rained?

When a fuel pump goes, it can also take out the relay as it's the source of power for it (increased resistance=increased heat=toasted relay). A relay is also easy to swap in and out to see if it's the culprit, any CB-1 buddies nearby you that can do a two second swap?

Don't also rule out wiring and the like. If it has a crummy ground, bad connectors or corroded wires, it could cause it to do the same thing as well (the clicking and the noise).

Check your wiring first, then the relay and then the pump. At least that's the way I would go. I'm not too knowlegeable about Honda CB-1s but that's what I would go through on a vehicle with a fuel pump. If you have a manual and it gives a flow rate, you can test the pump and rule things out that way as well. By the sounds of it, with the clicking at the pump, I would assume that first.

-Randy

ranakin400 · « **Reply #4 on:** April 09, 2006, 10:43:07 PM »

there no cb1 's around me that I know of. I think they are harder to come by vs. the B4. Finding used parts are hard too and new are expensive.

I ll check on the wiring. thanks for the advice....