Starting circuit diode and fuel pump relay ?

[mspookw]

I'm working on a '86'vr that I bought as a parts bike. The dealer said that it would only run if they poured gas down the carbs. He didn't want to mess with it. Turns out the fuel pump relay had some thing rattling around inside it, cut it open and found little electrical stuff burned off.

 

Question 1. Can I use the Class relay in place of fuel relay? It plugs right in and runs the fuel pump but, it looks way different than the correct relay. (I'm eliminating the Class system)

 

Question 2. Is the diode in the starting circuit essential or can it be bypassed? When in neutral the start button wouldn't work I pull the clutch lever, button works. Tested diode

D2 not working properly shows infin. on both poles D1 ok resister read 8.3 omhs. When I jump the D2 poles the start button works fine.

 

Mike

[dingy]

I wouldn't use a standard relay for the fuel pump relay. It may cause a failure of the TCI.

 

Attached is a picture of a 1st gen fuel pump relay inside.

 

Some of the circuitry is a snubbing circuit for the coil of the relay. This helps bridge the pulses that are coming from the TCI.

 

A problem that you may have is that when a relay has power removed from it, the coil induces a voltage spike into the controlling circuit. This is due to the energized armature field collapsing. With the armature being tied into the TCI, strange and bad things may happen.

 

If you are interested in this relay, PM. I cut the cover off of it, but it can be reattached, and still be functional.

 

I probably have a diode pack here somewhere also.

 

Gary

[jasonm.]

that is a very unique relay...as it also has what appears to be 2 capacitors

[dingy]

Here is a better picture.

 

Couple of transistors, diode, 2 capacitors and about 6 resistors. Along with an on board relay.

 

Gary.

[Squeeze]

The FPR is a Safety Device, it allows the Pump to get Voltage for a Amount of Time, like 5 Seconds, and when there's no firing Signal from the #2 Cylinder, it shuts the Pump down until there is a Fireing Signal...

 

You better replace the Relay with a used one instead of taking any Chances