VF1000 fuel issues

Hey guys, new here and was looking to get some advice on my troubleshooting. I recently started working on a 84 VF1000 that has been my dads bike since the 90's. The bike was used regularly until 2010 and then started once every few months until 2019. Bike will turn over but not fire.

Replaced the old battery.
Syphoned gas from tank and replaced with new gas. (old gas looked to be fine when removed)

I cannot hear the fuel pump priming once the key has been turned into the "on" position. I know I can test the wires coming into the fuel pump and there seems to be some relay or fuse that also goes bad. I just can't for the life of me find where to actually test on the bike with my meter.
-Fuel Pump does not prime in the "On" position, ended up being a stuck fuel pump

Update#1
The bike will now idle and can rev. I notice that she sits at around 2,500-3,000 rpm once it has some heat in it. I checked the mixture screws and they are 3-3.5 turns out depending on the screw. She also likes to pop a bit from the exhaust when I get on the throttle. I'm thinking she is running rich because of the mixture screw. For the high idle I was initially thinking the idle was set high, but she jumps around in revs a bit which makes me think there is a vacuum leak.

What is the factory setting for the mixture screws?
Where is the idle adjustment on these bikes?
-Found the idle adjustment between the carbs. Was having issues with throttle sticking before which was preventing the idle from dropping when I turned the knob.

 

The pumps on the VF/VFRs do not "prime" when the key is turned on. Sometimes you'll get one click when you turn the key. They only pump when then the engine is being cranked or when it's running. The fuel pump relay is on the left side near the regulator / rectifier under the side cover. You can unplug the relay and jump 2 wires to bypass and see if the pump is working (Blue and Black??). I'm just going from memory, but you can try a couple combos til you find it. There's a turn signal relay in that area too, so be sure you've identified the right relay.

The relays are know to fail. I wire in parallel toggle switches on all my bikes to prime the fuel system (like after winter storage) or to save my ass if the relay fails out on the road. There are many people that just permanently bypass it, but I like to keep it as long as I have my back up plan in place. It has saved me twice on two different bikes: Once in the middle of a floating bridge and once pretty far out in the country.

Don't rule out the possibility the carbs need a proper cleaning. Even starting every now and then is often not enough to eliminate carbs fouling up.

 

Didn't know that, at least jumping the relay seems easier than chasing wires.

Yeah trying to rule everything out before I go for the carbs. Haven't worked on carbs a whole lot, a bit daunting especially when parts seem so hard to find.

Will keep that in mind for the future lol

 

Parts you need to take care of the carbs are available. Suitable Viton o-rings can be sourced WAY cheaper than OEM. Reach out before you source any. I rebuild my V4 carbs for about $3 in rubber.

The intake boots will be the biggest expense and I highly recommend replacing them if the carbs have to come out.

 

if you heaR THE PUMP TICKING alot WHEN YOU TURN ON THE KEY IT Suggests that the pump relay has ALREADY been hotwired. (blue to blue/black)

 

So I ended up taking the fuel tank off, pulling the fuel pump and changing the fuel lines. The fuel pump was the culprit, whaled on it with a hammer for a while and it started right up after. Seems like the carbs are a bit gunked up as it will hold idle with about half choke but anything else it will die. Going to put some carb cleaner through it this week and hope she clears up, if not looks like I'm going to be pulling those carbs.

I went through the clutch master cylinder and found that what ever fluid had been in there had turned to solid....fun. Cleaned it out then blew out the fluid in the line going to the bike. After refilling it and attempting to bleed it I cannot seem to build pressure, I can see the piston moving inside the master when I look in from the top but it won't build pressure. I'm thinking a seal or something has gone out.

I have also been having issues with my front brake, where even after bleeding it the tire and lever will lock up after letting it sit for a few days. Bleeding it again will loosen them both back up. Not sure what it is as it doesn't seem to be an issue with air in the lines.

 

to get pressure in the clutch mc........try removing the slave cylinder and use a C-clamp to hold the piston fully retracted. you may need to remove the mc banjo bolt and bleed from there first.

you know the carbs need work if it only idles with choke on, and cleaning chemicals seldom work, but you can try seafoam.

make sure the front brake mc has an air space above the fluid, not too full.

 

Updated Post

 

I would only add a note here to say, do NOT spray the aerosol type carb cleaner into those carbs while they are still fully assembled. many carb cleaners will turn the rubber diaphragms into goo pretty quick if it gets into that top area under the round chrome cover.

 

So as I now have the time and money to work on her again the sauga continues.

The bike always had a bit of a grinding issue on the starter where it wouldn't engage 30% of the time. Well that has now become 90% and I'm going to have to pull her out. It sounded to me like maybe I had lost some teeth on the starter but I won't know for sure until I pull it. Any advice on a replacement if I need to go that route? Seen a few oem ones on ebay.

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Starter clutch??

https://www.ebay.com/itm/125031904076

 

More likely the starter clutch, not the starter motor. BUT... the VF1000 starter motors are shit (2 brush design) and I recommend replacing it regardless. Buy a 86 / 87 VFR 700/750 motor. I have installed them in all 4 of my VF1000. SO MUCH BETTER. 4 brush design, spins up so much faster. The power cable stud is in a slightly different location, you just need to remove one of the front cable holders on a clutch cover bolt to gain enough slack.

Sometimes a starter motor that actually spins everything up at the right speed can help a slightly worn starter clutch engage better.

Good luck!

 

Good to know, I will be pulling the starter this Saturday and putting some power to it to see if the noise was from the clutch or the starter. But that sounds like a good idea to swap while I have it off.

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Thanks I was looking at this exact one earlier. I don't fully understand how the clutch works so I was assuming it was the teeth on the starter rather than the clutch but this makes more sense.

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Get yours apart and look for cracks in the housing. Pretty sure you can still buy the rollers new (recommended).

And buy a VFR starter!!!! SERIOUSLY. Made such a HUGE difference.

 

The angle of the spring loaded rollers bites one way, and free spins the other. The "crunching" you hear is it biting and releasing.

 

Yeah I'm 100% going to grab one of them and make my life easier, are the rollers the wear items in the starter clutch? If I don't have cracks in the housing could I get away with just replacing them?

Thanks for all the advice!

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Springs, rollers and a VFR starter. Life should be good.

When you get your new-to-you starter. Take it apart and hose it out with some electronics cleaner. It will be FULL of brush dust. Inspect the brushes... they are usually fine, but can be replaced. You can sand them a bit for a fresh surface. Take an old school red pencil eraser and clean up the armature. Pay close attention on disassembly of the order of things, and beware some washers like to stick to each other or the end of the armature... until they don't.

Win.

 

VFR starter swap for the win! I did that to my '84 VF1000F and it was a 100% improvement. I sold the VF, but it made my sale go a lot easier when I hit the starter and it fired right up. GL on getting the bike going!

 

So got to the starter clutch today and found some issues. The housing is cracked along the edge in at least two places that I can see, looks like I gotta replace the whole thing. I also noticed that the 3 bolts holding the starter clutch together were not even finger tight in there, I could free spin them using one finger.....to the point where you can actually see some wear on the case from them backing out a bit.