Latest acquisition....original owner 1983 VF750F - Euro version

Put your probes in the power connector for the fuel pump. When you crank the engine, you should show power. If not, the relay is not doing it's job.

 

You're talking about the FP cut relay, right?

 

You're starting to confuse me. Yes, that is the relay I am talking about. Would I be talking about the turn signal relay?

The power to the fuel pump. The 2 wire connector. If everything is hooked up as stock and working, when you crank the engine, the fuel cut relay should allow power to be routed to the fuel pump. If you read 12V at the FUEL PUMP when cranking (provided your bike can produce spark), then the Fuel Cut Relay is working and doing it's job.

If you just want to see if the pump works, then just jump the relay (Black and Blue (???) on the bike harness side) and turn on the key.

 

Alright thanks.

I will do some testing tomorrow.

 

Making progress, I think.

With the fuel pump attached to it's normal connector on the bike....but no fuel lines attached....and the bike running off a fuel bottle. The fuel pump only works when I jump the bike connector for the fuel pump relay: Black-White.

I tried jumping the other wire combos, Black-Blue, etc. but no go. Has to be Black-White.

In theory this means the 2 fuel pump relays that I previously tried to use are BOTH faulty? Seems a bit odd, but at this point I'm just trying to confirm what the problem is, period.

So, I can put everything back together....and by jumping the relay (Black-White) until I get a working relay - the bike should be operational as normal?

Thanks!

 

Got everything put back and it now starts and runs as normal.

I can also now hear the fuel pump come on just before cranking. Clat clat clat clat.......

Funny thing is.....while the bike was running - I removed the relay jump....and the bike kept running. Tried several times to start and run without the jump and it still started and ran fine.....without the jump.

Wonder if this means the fuel pump isn't running.....and the bike is just using what fuel it has left in the carbs (?) I'll have to do again and listen.....

I will install a jump anyway just to be sure and also set about resistance testing my 2 FP relays, to see what that shows.

The important thing is now she's back running and I can move on the the next chapter. Getting her back on the road.

BTW....I tested my other fuel pumps while testing on the bike, per previous post, and verified the FP that came with the bike doesn't work.

And now I have 3 extras that do work....

 

OK..............got it.

Ran the bike until it shut down.

Installed FP relay jumper.

At start heard the FP come on...klat klat klat.......and she started and ran just fine!

This verifies that I DO need a jumper, until I can get a working relay, which I will pursue.

The bike will run for a while just off the fuel in the bowls and then nada.

Thanks to everyone for all their help. I'm not a mechanic and still learning so appreciate your help and patience!

 

The pump only pumps when pressure in the line runs down.. like the bowls running low.

Then it pumps a few times to fill the bowls and the line pressure is restored, pump stops.

The fuel flow test in the manual wants you to apply 12v to the pump and aim the line into a container. That will make the line pressure always low and you can record the output In a timeframe.

Nice to have spares that work

Sent from my SM-S911U using Tapatalk

 

Thanks....makes sense.

I ran it a little more......then put the jump in. When I went to start it I heard the klac klac klac so I should be good now, at least on this issue.

 

New issue (maybe).....

I noticed my clutch lever didn't have a lot of resistance, so did a slight bleed and now it's working good again.

This in preparation for a ride....finally.

To test it I put the bike in gear and started it with the clutch handle engaged. It started fine. I slowly let the clutch out and it stalled, due to being strapped down on my lift. I felt the wheels trying to move.

So here's the problem. When I went to put it back into neutral I couldn't get it done. Going by the neutral light not being lit and also it stalled when I let the clutch out.

It's one down and four up. Doesn't seem to want to go down again from 2nd. Probably just an adjustment. Remove the lever and turn the gearbox shifter piece, maybe first?

 

OK... first of all, good job.

Sounds like your relay is not working. You fine running jumped. One of my Hawks is like that. I put a temp toggle switch on and just have never got around to installing the Cut Relay. I was guessing on the colors, they changed over the years. What ever combo makes the pump work is the right one. {wink}

Motorcycle transmissions like movement to change gears / find neutral. Rolling the bike a bit back and/or forth will usually let the bike find first / neutral / second pretty easily. I'm sure it's just something like that.

 

Thanks....I figured it was something like that. I just tried again and got the neutral light back on.....but it's still in (first I guess) gear. I'm not going to do anything more until I get it off the lift and on the ground ready to ride.

Bike hasn't been driven for a few years.....probably just needs to get going again for the gearbox to work properly.

 

Good morning and Happy Sunday!

The gearbox "issue" went away this morning straight away. I was able to shift her right into 1st and then back to neutral with bike sitting still - no worries.

OK so we're ready to roll her off the lift table now, eh?

Not so fast my friend. Wheels not freely spinning as they should - which means the brake calipers probably need attention. Not a big deal for me at this point as it's a good investment for future mechanical interests.

What was cool is I lifted the back up with a paddock stand and was able to sit on the bike and run her through all gears for the first time since I've had her. And probably the first time in years. Shifted just fine and engine ran good (enough for now).

So it's on to the brakes! Something I have never done but looks fairly straight forward.

 

Do you know how to approach the brakes? There's a good write-up here or on VFRdiscussion.

 

Thanks - I am going by some online tutorials plus the service manual but would really appreciate seeing the write-up here, as well.

Do you have a link to it...or can tell where it's located?

Thanks, bmart!

 

I suggest that you take the time to search both sites, as it is your bike. I don't have them handy.

You have hydraulics and mechanics. You'll want the fluid system to move fluid properly and without any hangups/blockages. You'll also want the mechanical bits to work properly, from the activation by lever/pedal all the way to pistons and pads moving freely. It isn't hard, but you want it all correct.

 

OK thanks, bmart!

I just thought there was one specific thread that everyone considered the gold standard. I'm OK doing searches myself for info.

Pretty sure at this point I'm up to speed on what's involved.

My rebuild kits are due here Wednesday. So I plan to dig in on Thursday. If I run into anything I'm unsure of, I will post here.

Cheers!

 

My brake caliper rebuild kits arrived yesterday, a day earlier than expected (always a nice surprise) - so today was the day to do the brakes.

I decided to start on the fronts. Everything going OK, so far. This is my first time rebuilding motorcycle brakes, so I'm excited for the learning experience and at the same time a tad apprehensive with concern I might mess something up.

I got the front wheel up by using this scissors lift that I bought last year, but had yet to use. Man it really did a great job for me, so was a wise purchase. I used a small 4x4 block of wood to go between the exhaust pipes and mate up with the lift point under the engine.

I kept the brake lines attached while removing the calipers so I could use the lever to pump out the pistons. Worked great except for one piston, so that's the one I'm working on now.

One thing I had to do is refill the brake master cylinder 2 times before I could get the 3 pistons moved out far enough.

So far I've used about 50lbs. of compressed air and the piston isn't moving out any further.

I have a larger air compressor but haven't replaced the busted hose on it yet (I have the replacement hose) so might have to do that.

I also have a device coming later today from Amazon that is designed to help extract brake caliper pistons:

AMAZON

In the meantime I will clean what parts I can.

BOTH brake calipers were SUPER TIGHT on the front rotor. No wonder I couldn't roll the bike backwards off the lift!!!

FWIW, the pivot bolts/sleeves and caliper pins moved pretty freely, so there's that.

I think once I clean up the pistons and replace the seals she'll work pretty smoothly.

The rear wheel does move OK but not as freely as I'd like so I will do that caliper too when I get these done.




Those are 2 wooden paint stir sticks you see inserted to keep the free moving piston secured, while trying to get the stuck one out....

 

Still can't get that piston out, despite trying the new tool that arrived.

I have the caliper in my Ultrasonic cleaners right now with full strength Simple Green. Going to do (2) 30 min. sessions at 50 deg C and see if that helps.

I have all the other brake stuff in there too so if nothing else I'll have some clean parts!

I also ordered another repair kit that contains 2 new pistons, in case I can't get this one out and have to resort to a method that damages the piston yet preserves the caliper.

I may take it to my mechanic tomorrow if all else fails. He and his son are good at doing stuff like this.

This piston may be responsible for the front wheel not turning problem all by itself. The funny thing though is the bike did roll OK before I worked on the brakes. So it must have just gotten "stuck" the last couple weeks.

 

The new tool.......that didn't work on this piston....piston just too stuck!!!