V65 Magna payment bike update

[oldhondajamie]

Getting closer to making this Magna a reliable runner. Just figured out I have a short in the fuel pump relay wiring, the white wire (power from relay to pump) is shorting to the frame some where, it caused the relay to go up in smoke the first time I put power to the system. I replaced the relay thinking it was bad from age. I put power to the system again with a brand new relay and as soon as I turned the engine over I heard a loud crack, the back of the relay was completely blown off and it went up in smoke again. That was a $56 lesson in being through the first time, (sometimes I get impatient). Good news is the fuel pump is fine and I now know what the problem is, Just have to locate the short.

 

[slabghost]

Expensive lessons are not easily forgotten. I can't imagine how a short in a feed wire could cause that kind of damage.

 

[Denver]

We call those mistakes experience.

 

[Ansimp]

$56!!! Is that a tachometric relay?

 

[oldhondajamie]

Its a fuel cut off relay. It has 3 poles, it gets a signal from the coils to energize the relay and signal when the pump reaches max pressue for the system to shut the pump off

 

[Ansimp]

oldhondajamie » Tue Oct 06, 2015 8:12 pm[/url]":1fccxhdp]
Its a fuel cut off relay. It has 3 poles, it gets a signal from the coils to energize the relay and signal when the pump reaches max pressue for the system to shut the pump off

Tachometric relay :yes:

 

[Denver]

You CAN wire in an INEXPENSIVE relay, so it only gets power with ignition switch on, but kill switch or lack of current will stop pump, & carb's will stop fuel by the needle & seat. Not the same as factory, seems one could use same the same wires but leave the shut off wire out of the picture. :headscratch:

 

[joedrum]

OOPS

 

[oldhondajamie]

Denver » Tue Oct 06, 2015 9:09 am[/url]":24qkikro]
You CAN wire in an INEXPENSIVE relay, so it only gets power with ignition switch on, but kill switch or lack of current will stop pump, & carb's will stop fuel by the needle & seat. Not the same as factory, seems one could use same the same wires but leave the shut off wire out of the picture. :headscratch:

You can but you would need a pump that has either a pressure switch or a relief valve built in, the factory pump will over come the needle and seat and flood the carbs If you don't have the factory cut off relay to regulate flow. It works by sending a signal from one coil every time it fires, that way it regulates fuel flow by rpm and not pressure

 

[Denver]

That's why was scratching my head, :headscratchid't know how much pressure stock pumps put out. Ones i've installed with relays, are 84 Prelude pumps, have a shut off valve of some kind built in,only go to 3lbs psi. :yes:

 

[Ansimp]

oldhondajamie » Wed Oct 07, 2015 10:15 am[/url]":35glnlxa]

Denver » Tue Oct 06, 2015 9:09 am[/url]":35glnlxa]
You CAN wire in an INEXPENSIVE relay, so it only gets power with ignition switch on, but kill switch or lack of current will stop pump, & carb's will stop fuel by the needle & seat. Not the same as factory, seems one could use same the same wires but leave the shut off wire out of the picture. :headscratch:

You can but you would need a pump that has either a pressure switch or a relief valve built in, the factory pump will over come the needle and seat and flood the carbs If you don't have the factory cut off relay to regulate flow. It works by sending a signal from one coil every time it fires, that way it regulates fuel flow by rpm and not pressure

It doesn't change fuel pump pressure, it is a safety device so that if the engine has stopped but the ignition is still on the fuel pump stops pumping.

 

[Denver]

We went through this dance already & know what its for :headscratch: !!! Read the earlier post if you forgot, :thank_you: Prelude pumps shut off at 3psi, & won't over power needle & seats IF their doing their job, :smilie_happy: & pick up voltage from pump, will cut the power supply, that comes from coil pulse, remember?. opcorn:

 

[oldhondajamie]

Pretty sure i've found my issue the ignition switch was dirty not providing power to the fuel relay circuit so it defaults to ground. I have path to ground with key off but know that working the key on and off (testing) it has cleaned the contacts and i no longer have path to frame with key on. Checked though other circuits and every thing is working. I will pull the switch and see if i can get to the contacts to clean proper. Now just need to get new relay.

 

[joedrum]

yep same problem i had ...with my c5 ignition hooked up to relay ...it direct to battery now with switch ...and i suffer no problems ever again ...