New to Moto Brick.. Fuel Pump issue

[david_hawkins]

Hello all, thank you and please help?!
I'm an R bike guy and bought my son a 87 K75S and rode it back to Iowa from New York.. the SOB who sold it to me didn't mention the hole in the fuel tank.. oh well... buyer beware..
So.. took it apart.. tank got welded/epoxied/lined.  That was last fall.  Last month the boy and I greased the clutch splines and put it all back together. 
Now.. after getting the tank back on, I get nothing from the fuel pump..

Any ideas?.. I'm testing for voltage on the yellow/black wires.. but nothing out of the pump.. It worked when I pulled it out last fall...

Thanks,
Hawk

[cy7878]

if you hook the pump to a 12V power supply, will it spin?  From what I have read, it's not unusual for the pump to seize due to old age.  I saw a generic set up on fleabay for about $80, which I may try if mine ever fails.

[motodude]

Start simple.

Check the connector on the right side of the bike (going to the tank).  Sometimes they lose connectivity (and sometimes I forget to plug it in).  You can use one of those flat four wire trailer connectors as a replacement if yours is bad.

Tom

[mjydrafter]

I had to re-soldier the connections to the FP wires where they come up through the tank to the level sending unit.  I had to replace the one of the wires, as years of fuel had taken it's toll on them.  It was missing about 75% of the insulation :yow.

The old wires and insulation were really brittle.

[WayneDW]

Welcome Hawk.  Hope you figure it out.  Kudos on taking on a project with your son.
What part of Iowa are you in?

[Scott_]

Ifn I'm not mistaken the older jetronic control systems only activate power to the fuel pump when the starter button is pressed (motor turning).
Not like the newer motronic systems that prime the pump when you turn the key on.

I agree with the above, check the connector at the outside of the tank, apply some power to the terminals of the connector to test the circuit to the pump. Occasionally the circuit can break where the conductor passes thru the float/level sending unit assy on the underside of the tank. Not too terribly common, but it has happened and can be intermittent.

[grant71]

Yes. Thats what happened to my k100. Intermittant engine failure and then permanent cut out. Replaced fuel level sensor and connected 2 wires from battery to under tank conn and fuel pump A1 OK

[david_hawkins]

Thanks Everyone,
Wayne, I am in Dubuque.  The boys are in Iowa City and Cedar Falls, after school gets out for them, we're heading to Oregon to see my folks, riding out/back together.  This will be their first big multi day trip with me.. we'll see how they do..

I did the test, and I'm getting voltage to the spade connectors thru the four pin plug... Thinking I might rewire that.. not sure yet..  Went to Advanced Auto Parts and bought the replacement pump that the IBMR site showed for 'equivalent' part.  Tonite I'll replace it and see how it goes..

and Yes, it only gets power when the starter button is applied.. not like my R which starts when I turn the key..

I'll post how it goes tonite...  He's getting anxious to get on his 'new' bike.. spring is finally starting to show up here in Northern Iowa..

[Scott_]

Hawk, K-bike or not, if you are interested we are having a get-together and ride in the middle of July. Meeting in Dubuque and then riding from there.
Check out this thread. http://www.motobrick.com/index.php/topic,3975.0.html

[WayneDW]

Thanks Everyone,
Wayne, I am in Dubuque.  The boys are in Iowa City and Cedar Falls, after school gets out for them, we're heading to Oregon to see my folks, riding out/back together.  This will be their first big multi day trip with me.. we'll see how they do..

Sounds like a great trip with the sons.  The less I see my grown kids as they live their own lives, the more I appreciate every thing like that which I've done with them.

[david_hawkins]

Thanks again everyone, the issue was the water pump.  we got everything put all back together/buttoned up and she started like she was running last nite!...
The boy got his first ride on his 'new' moto brick!!  So now he takes it back to school and gets familiar with hit before he head west in 3 weeks! 

[david_hawkins]

Sorry.. meant FUEL pump.. I'm tired..