Getting My 86 Fired!!

[johnrmclean]

So on my 86 VFR resto I got the tank on and it appears I have gas gravity feeding to the pump but I can get the motor to ignite. Motor spins good but not sure the pump is pushing fuels to the carbs. Don't hear anything at the pump and don't smell any gas. Suggestions on what to check and where to start are appreciated!!

Rookie

[crustyrider]

Originally Posted by johnrmclean

So on my 86 VFR resto I got the tank on and it appears I have gas gravity feeding to the pump but I can get the motor to ignite. Motor spins good but not sure the pump is pushing fuels to the carbs. Don't hear anything at the pump and don't smell any gas. Suggestions on what to check and where to start are appreciated!!

Rookie

try to jump the pump..Hot wire it so to speak your manual should tell you how... but first check alll your fuses and make sure its plugged it...sounds stupid but it happens... you can also gravity feed some gas into the bowls so you can see if the bike will fire up..

Good luck

[squirrelman]

you can tell whether the carbs have gas by cracking open the drain screw on the bottom of each carb......

[johnrmclean]

Sorry no manual! No wiring Diagram

So the pump has a green and a black with blue stripe wire

Any idea which one is the positive lead??

Thanks

[TOE CUTTER]

The green is ground and the black blue is positive.Run the pump until it shuts off to charge the carbs. If this is not done the bike will take forever to start as the pump fires once per revolution and it will take quite some cranking to fill the lines and all four carbs.

[johnrmclean]

Ok sounds good. I will try that in the morning and report back.

[johnrmclean]

Ok ..I jumped the pump and primed the bike buy might have got a little over zelous as it flowed out the overlow.

Then I cranked the bike and it basically started right up but ran a little rough. I had trouble keeping the throttle up when I noticed the fuel was coming out the overflow tube and dumping on the ground pretty good .

What's up with that? Any advice now??

John

[squirrelman]

Very common problem after prolonged storage: your float needles are not shutting off fuel properly after float bowls are full.

Drain carbs and apply compressed air to fuel tube leading from pump to carbs.

If that doesn't work, carb removal and cleaning are in order.

[crustyrider]

Originally Posted by squirrelman

Very common problem after prolonged storage: your float needles are not shutting off fuel properly after float bowls are full.

Drain carbs and apply compressed air to fuel tube leading from pump to carbs.

If that doesn't work, carb removal and cleaning are in order.

or the Orings that seal the fuel rails aren't sealing......let them swell a bit as they are expanding as the fuel hits them they should seal right up....unless you can see were the fuel is leaking from.

[squirrelman]

Crusty, wouldn't the fact that fuel is coming from the overflow tube ( the vent line actually) rule out leaky fuel rail O-rings ??

[crustyrider]

Originally Posted by squirrelman

Crusty, wouldn't the fact that fuel is coming from the overflow tube ( the vent line actually) rule out leaky fuel rail O-rings ??

whoops didnt catch that part saw it and it went right past my eyes......it wouldn't rule it out cause they could still be leaking

sounds like the float needles to me are stuck....yep yep

[RauBurger]

Hey guys,

This is my first post here, but I'm the person who just bought this bike, and I've got a question for you. The engine starts but it won't stay running for any length of time, the carbs arn't over-flowing anymore. i was wondering if you guys had any sugestions.

Thanks

-Rob

[Rollin_Again]

More than likely the carbs need to be removed and cleaned.

Regards,
Rollin

[RauBurger]

that was gunna be next plan of action, thank you for the confirmation. I'll post back with the results.

[squirrelman]

With soap and water ??

[RauBurger]

alright guys I'm back. sorry it took me a week, i was waiting on parts to come it. So the bike now runs, and it runs alright with no load, it has a nice responsive throttle and sounds good, but once you get it on the road and you go above 3k rpm cylinders start to cut out, and then in, and then out again, rinse lather and repeat. I have some sea foam running through it, but do you guys have any other ideas?

[TOE CUTTER]

Originally Posted by squirrelman

With soap and water ??

I may have a set of 48 state carbs I can send on the carb exchange program.I will look at them in the morning and let you know.If they are good I will run them on a good known bike and send them to you but you have to pay the postage. Not alot to ask......beer money welcome as well.After that it is a pump or relay issue I would think.

[squirrelman]

NOW THAT'S the best deal ever !!!!!

Make sure it's great beer, not Bud or Coors.

[tinkerinWstuff]

Originally Posted by squirrelman

NOW THAT'S the best deal ever !!!!!

Make sure it's great beer, not Bud or Coors.

Yo - easy there Hoss. Both Bud and Coors are brewed right here in Colorado!

Although, personally I like Michelob Golden Draft Light. It's an Anheisure(whatever) product but it's only sold in 5 upper midwest states to compete with Miller Light.

[NWA_VFR700F]

Originally Posted by tinkerinWstuff

Yo - easy there Hoss. Both Bud and Coors are brewed right here in Colorado!

Although, personally I like Michelob Golden Draft Light. It's an Anheisure(whatever) product but it's only sold in 5 upper midwest states to compete with Miller Light.

haha, I was born and raised in Colorado and always grew up with Coors Original And even today living in Arkansas, the only beer i drink is Coors

[RauBurger]

so i got the new boot to seat the carbs to the engine and installed them and there was a difference immediately. I took it out on the road and while there definitely more power it still seamed like it was lacking once getting into the higher gears. It would get jerky sorta like i still had cylinders going out. But its definitely better.

[tinkerinWstuff]

You're the 4th person here with an '85 or '86, I know of, having the same problem. Well, symptom anyway...

be sure you didn't interchange main jets between carbs. Although the carbs look alike, two are side draft and two are down draft.

do you have the vacuum lines for the float bowl vents etc etc all hooked up correctly so there is no open vacuum leak?

Did you balance the carbs? The slide is operated by engine vacuum and if the balance is out of wack then it's possible for the cylinders to fight each other.

All that assuming the carbs were cleaned properly, float level set right, sufficient fuel supply, and spark.

[RauBurger]

thanks tinkerin, I'll check that stuff.

Heres another little thing i noticed. When i cold start the engine it only starts up on the right two cylinders. the other two only come in when it warms up, this does not seem like normal behavior. any more ideas? do think my two problems are connected (I do)?

[tinkerinWstuff]

Originally Posted by RauBurger

thanks tinkerin, I'll check that stuff.

Heres another little thing i noticed. When i cold start the engine it only starts up on the right two cylinders. the other two only come in when it warms up, this does not seem like normal behavior. any more ideas? do think my two problems are connected (I do)?

It is possible that the problems are connected but not deffinately.

The two cylinders lacking to fire when cold would typically point to the choke circuit. When the engine is cold, it needs more fuel. A warm engine will atomize the fuel easier and creates a mixture more conducive to ignition. Once the engine warms up a little from the two cylinders that are firing, the other two come on line from the fuel in the pilot circuit.

When you took your carbs apart, there are three bronze "stacks" that stick down into the float bowl. Two of those stacks are removable and they are the jets. The third one isn't removable but the passage goes all the way up the carb housing and opens up again in a hole near the slider diaphram. I believe this passage is part of the choke circuit too and it's easily missed.

You have to remove the silver caps at the top of the carb (carefull not to tear the diaphrams) and you'll see the choke plunger and a few more holes to make sure you have clear. At the front of the carb, where the air would come in to the engine, there may also be bronze nipple sticking out with a hole in it. This should also be part of the choke circuit. When the throttle butterfly is closed and the choke is open, air enters this tube, mixes with fuel in the passages I mentioned earlier, and enters the engine thru a port at the twelve o'clock position just behind the throttle butterfly.

[tinkerinWstuff]

The reason I say this problem may not be connected to your surging issue is because the carburators are actually 4 or 5 different systems all in one. When you roll on the throttle, the vacuum created behind the throttle butterly is reduced and the choke circuit no longer delivers fuel. At that point, the pilot jet is delivering fuel to the engine. As you continue to roll on, there is a transition from the pilot jet to the slow speed jet, and the transition continues to the main jet/jet needle, and on to the main jet only at wide open throttle.

And all that said, your problem can be caused by other factors as mentioned earlier - vacuum leaks, fuel filters, inadequit spark...

Did you find the fuel filter screens behind the float needle? Unscrew the needle/seat and there should be a fuel filter/screen there.