VF500 Carb Rebuild Kits Resource for parts wanted.

Gas went through so fast it was hard to determine where it came from. I am suspect of fuel tube junctions and fuel supply hose from Y leading from petcock, I replaced the left one looking from rear of bike to front, as the originals are hardened pretty seriously. The replacement hose I installed was slightly larger ID. I have ordered 8mm hose to replace the replacement. I think that the 7mm x 2 gas tube orings were pretty loose so I ordered 7x 2.5mm from Orings and More. I am not sure any of the fuel got to the float bowls. Though... There must have been some in the bowls as when I tipped the carbs upside down to inspect for leakage, they had been sitting for a half hour, more fuel dribbled out throught the throats? This would indicate to me that there was fuel standing somewhere?

I am wondering if the Choke valves are sticking partially open also, not sure what impact that would have? The fuel went on the floor as fast as I poured it. So I will need to just pick away at it.

Still have a week or so to work on her before I need to pack her up to store.

Thanks for the Adult Supervision

WaveyDavey

 

i don't think using larger fuel tube O-rings will help. choke valves have no potential leakage problems.

carbs are real easy to work on, right ?

 

What is your guess?

 

With the immediate quantity of leaking fuel, it does sound like it is fuel tube / hose related. It has been a very long time since I have worked on 500 carbs and my notes could certainly be wrong. Seems like there's a few possibilities:

You have done something wrong. But if you got the carbs back together I don't think you have mixed up parts and that is your issue. Still possible.

Fuel tube o-rings are not the right size. If they did not feel snug and required a firm push with some lube, then perhaps they are wrong. My info could be wrong. I will be very surprised if they don't take the 7x2 oring, but those carbs are also different from the other V4 carbs. Every other V4 takes 7x2 on the fuel tubes from the 83 VF750F, thru all years of the carb VFRs 86 - 97, the VF1000F/R and the ST1100. Mis-labeled orings? Doubt it, but anything is possible.

Something is damaged. The fuel tubes are aluminum, so I doubt it. The later 750s and 1000s can be suspect, as they are a plastic that is old and brittle and can be cracked very easily if the carbs are mishandled during disassembly. I have had cracked fuel tubes on a 86 VFR that I didn't discover until VERY close examination.

You are going to have to try and determine where the fuel is really coming from to get to the bottom of it in the next round. If the fuel tubes with the new orings are truly "loose", they will likely leak. But I'm surprised at the immediate volume you report.

 

Yeah, that's not right. Not sure when I'll be able to look at some reference carbs to answer your question about re splitting.

Cheers

 

Got the carbs, gas trans tubes, air tubes back together, and bench sync'd . Leak checked no leaks. I hope to rig up a bottle with some gas and see if she'll start.
I am going do the petcock conversion eventually I think, but need to do some more stody. I may never be able to get all of the sludge out of it so may just install and inline fuel filter until I decide what to do. I will have more later.
Wavey

 

Time to rig a fuel bottle to test and maybe balance. Decided to ultra sound the Petcock again. Still very grubby.

More Later

Wavey

 

In contemplating not being able to get my petcock valve cleaned of goo has anyone used an inline filter between the fuel valve and the Y junction going to the carbs? It seems pretty crowded in that area and not sure I can hack a filter in there. I was looking at some that have 90 degree offset tube fittings? I am heading out to some auto parts stores and Harbor Freight to see what I can scrounge until I can come up with a clean petcock.

 

hey, WD do you have an air compressor ?

 

Sure do! Whatcha Need?

 

^^^ shoot some air into the oval-shaped area on top of the carb intake side. the slide should rise smartly; if not, then the slide diaphragm might be installed incorrectly, and the engine won't rev up.

 

I did do the air test all slides worked just fine. I hooked up a fuel rig and line earlier today, see picture, it fired a couple times. I pulled a plug put in one new one and it fired up and ran on all four for about 2 - 3 seconds. I put in another plug and couldn't get it to start again, the old plugs weren't terrible that is why I did not change them.. I just ordered four more. I only had two new ones in my stock. They are the same plugs as my KLRs. I am wondering if I need to put more fuel in the suspended bottle to create more positive pressure on the carb inlet?

When it ran it sounded really good, it wasn't dieseling or just runing on the cyl with the new plug. The spark does look a tad weak, but that could be lighting. The bike is sitting right in the sun. I will let my battery come back to life and give it another shot.

 

try hooking the bike up to a car battery as a booster.

 

That is more than enough gravity. Get the battery recharged.

 

Sadly I could not get more that about thirty seconds of run. It sound like she wanted to go! I have a charger with a start circuit so I had pretty much infinite battery life at very fast over turn rate. My gut is telling me there is still some reason that there is a fuel shortage? I was not able to cook an entire carb in my ultrasonic degreaser. While it was running at fast idle I tried to give a little throttle at which time you could here the slides open, that sucking sound, then it immediately died. After an episode of that it would no longer fire. I had to put my rig away as it has been raining since and I don't quite have enough room in the garage while I am packing to move. I am going to make one more attempt this weekend then I have to pack her up til I am relocated at the new digs.

Any words of wisdom or cosmic incantation will be appreciated and relevent.

WaveyDavey

 

Pack it up. Start again. Nothing is gonna miraculously change from what you describe. Drain the carbs and focus energy at the task in hand.

 

has it been determined that our man davey set his float levels correctly ?

 

It will be determined in his new home.