Well, after replacing a slew of electrical components in the hopes of staving off any future issues (preventative if any), warming it up, everything seems good, heading down the road, then it starts to die as if running outta fuel. Mang!! Plenty of fuel, cant roll the throttle it will die but barely idles and then nothing, as if its out of fuel. got it home, (had to pick it up in my trailer) troubleshooting begins. Bowls were like kinda empty but no sound from the pump. Spark on each plug, good. Im thinking, old bike, old ****. Pump bad? sending unit bad? whaaa? I hooked the pump up to a battery, thru the connector, thumping away, ok, still has some life. Traced the wires back to a module under the left scoop, black wire, blue black wire, it plugs into that big *** black thingy, Fuel relay? Well by passed that, pump thumping away, ok, this relay is bad, costly too. I hope thats the problem, any thoughts fellows? Im thinking all the crap I replaced, voltage regulator, starter solenoid, starter, being new items, the old electrical **** couldnt keep up. I know lame, but it all started after I screwed with the electrical. Next thing to go will be the damn sending unit in the tank! I can drop it out from under neath rite? Two phillip heads and then gasket.
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one2dmax
Well-Known Member
The relays don't go bad very often. Did you try switching to the RES position (even though you had plenty of fuel).? That is the "force on" position and will generally make the pump run regardless of the qty of fuel in the tank.
yup, that's the 1st thought as it started to die, no change. I was also busy looking for a place to pull over too, staging the heavy *** bike for a trailer rescue! But when I got it home, I pulled out the Factory manual and they actually had a trouble shooting tip & illustration showing by connecting a battery (I used my trailer battery, you know, then one that runs the electrical brakes?) perfect for scenarios like this, anyway, I ran wires to the connector straight off the pump, only two wires, black & blue black, the pump started to thump away. Ok, that's good, I traced it back to the fat *** relay, a bunch of wires going into it, other than the black & blue black, I guess the others are the sending unit & the reserve switch probably, anyway again, I connected everything up, carbs are empty, no thumping from the pump, I disconnected the relay, plugged my battery jump wires into the female white plug, black & blue black, pump thumping, good! But I'm still Leary, I will replace the relay, buy a new pump, hopefully, the sending unit is not ****** up. My 1st step will be is to get the new relay, keep the old pump, go from there.
sdt354
Well-Known Member
Connect everything back up normal and disconnect the sending unit plug. If it pumps, ditch the sender.
one2dmax
Well-Known Member
Also, does the low fuel light illuminate when you are cranking the bike (you should have both the oil and fuel red lights illuminate during cranking as a test of the bulbs).
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Well again,
When you screw with the electricals, you create problems. I actually found the original issue. I took it upon myself to move some grounds around, instead of the usual rite to the neg. battery post as it was from the factory, I chose like a ******* to ground the two eyelet black grounds which were on the neg. post and affixed it to the frame. of course, sanded it down to bare metal was not enough, one of those grounds is from the sending unit from the gas tank rite? the other ground, did not trace it, but, connected it all back up like before, key on, pump thumping, carbs fill up, bike started rite up, now the big test is to see if all the fuel ******** works, .i.e. reserve switch etc. No matter, alrdy ordered the relay, $57.00, new fuel pump $110, sending unit, Mang!! $172. Want to thank SDT354 for his suggestion, it led me in another direction to try, and it worked, thxs pal!! BTW one and all, this time I'll have a chase vehicle follow me on a good test run!!
When you screw with the electricals, you create problems. I actually found the original issue. I took it upon myself to move some grounds around, instead of the usual rite to the neg. battery post as it was from the factory, I chose like a ******* to ground the two eyelet black grounds which were on the neg. post and affixed it to the frame. of course, sanded it down to bare metal was not enough, one of those grounds is from the sending unit from the gas tank rite? the other ground, did not trace it, but, connected it all back up like before, key on, pump thumping, carbs fill up, bike started rite up, now the big test is to see if all the fuel ******** works, .i.e. reserve switch etc. No matter, alrdy ordered the relay, $57.00, new fuel pump $110, sending unit, Mang!! $172. Want to thank SDT354 for his suggestion, it led me in another direction to try, and it worked, thxs pal!! BTW one and all, this time I'll have a chase vehicle follow me on a good test run!!
sdt354
Well-Known Member
No, the black, 2 wire plug on the right side of the battery.
yes, mine has two eyelet grounds. one is the sending unit, the other not sure, no matter, I grounded everything OEM, everything is working, but still gonna replace all the old components regardless of them operating correctly, and will have a chase vehicle follow me...
one2dmax
Well-Known Member
And, the verdict was?
If you have aftermarket canisters for the exhaust, you can access the bottom better. If you have the OEM resonator/megaphone exhaust, I think you'll need to pull the gas tank. it's not hard, Buster has a thread on it, it may be a sticky. I did one yesterday, following his instructions, but decided to make it easier on myself by removing the rear wheel, the rear brake caliper, and moving the caliper mounting bracket out of the way. That took an extra 20 minutes, perhaps, and made it much-easier to articulate the gas tank out of the frame.
This allowed me much-easier access to the screw at the bottom of the plastic rear fender splash guard, you need that off to give yourself room to rotate the gas tank clockwise once the left rear footpeg mount is removed. I also removed the top left rear shock mount, but just backed-off the bottom nut, I removed the top shock eye from the frame, and rotated the shock, still attached at the bottom, backwards to give me the additional room to move the loose tank out of the frame.
On reassembly, I found it easiest to first locate the frame member that attaches under the seat, on-which the rear footpeg bracket is mounted, before attempting to fasten the three 10 mm machine screws holding the footpeg aluminum mount to the frame. Buster mentions about making sure the top footpeg mount is shiny-clean, as this serves as the ground on early bikes. Use some dielectric grease there, to ****** corrosion, and a lessening of your regulator/rectifier ground. Later R/R's use a separate ground.
Redbone
Well-Known Member
Way to stick with it, I'm sure she'll reward your diligence with many awesome rides!
unk:Well, thxs all, I just wanted to go ahd & pull the tank out anyway, check it out, clean up around it & hell, go ahd drop the swing arm out, check the bushings & such, of course, rust, corrosion, there are weep holes as well, naturally, clogged, of course! the usual crap which comes along with an old bike, but!! worth it, when you want to keep her forever, being my 3rd Vmax. Anyway, after replacing all those components I was screwing with, bike does start great, no more dimming when various components are on, my only two concerns left now is where to put the V/R now, next to the pipe is so *******, under the scoop, not much room for the time being, I retro fitted it above the fuel pump, & behind the starter solenoid, its like it should go there, fits very well, but it does get hot, not sure about regular air flow, I may have to cut my NEW! V/R wiring & lengthen them to reach the tail piece, I have a good spot for them, will look trick not a crappy install. The last item in the electrical round up prevent maintenance OP-PLAN (Operational Planning) is to replace the generator hub & associated wiring harness, why? Well, when I fixed my starter clutch issue, removing the side cover & seeing the hub, wiring did not look good, therefore, will replace, the best place to get it?? RMSTATOR guys outta Canada. They make absolute great electrical components, period.. My next biggg project is ordering the Damn Vmax Exhaust out of Belgium. Costly, (currently, exchange rate is high, $8-900.00) but looks real nice, sounds good, its on Youtube fellows.
