VF fuel system issues

In the Shed
41

Indeed, after some extensive poking about last night, I think you all may be right.

Going over every element of the ignition, down to the plug caps, everything checks out. I even mixed and matched the coils from the two sets to get the ones that fell best within the stated ranges.

Later today I am going to run it on gravity feed to the carbs with a full tank to see if the issue materialises.

I had done this as a stop gap some time ago and it got me home which sent me down the fuel issue route in the first place.

I’ll dig out the old pump and see if it is recoverable.

@dnapekko: that guide for changing the points would be great. Do you have a link to the yank forum?

42

I can’t find my own article anymore, but Wemoto has made a nice video: https://wemoto.wordpress.com/2013/10/07/repairing-your-motorcycle-fuel-pump/

If you google Honda fuel pump points, there are lots of instructions, same pump type is used in many bikes.

Pekka from Finland

43

Pumps…I’ve had this trouble.

Pattern chinese made CBR600 pumps fit, and if you fit them a little further back in the bracket you can get the curvature you need. Also use thick walled Viton tubing, this also helps. Either that or use some 90 degree adaptors and short pipes onto the pump.
What will happen is on the suction side the pipe will collapse due to being sucked flat, and you won’t get much fuel through. Hence the thick walled tubing.

If you want to rebuild the points in the pump they are the same part as Honda’s XRV 750 Africa Twin 1999

Hope this helps you some!

C.

44

Well joy at last!

I plumbed things for gravity feed without a filter and set out this morning with a full tank.

I got straight out on the motorway and cruised for more than 50km at 120kph and it never missed a beat.

So obviously the combination of the pattern pump and the new pipework has meant that something happens that overwhelms the pump’s capacity to deliver fuel under sustained load and that it seems the two forward cylinders, 2 and 4, get starved of fuel and cut out.

I looked at my old fuel pump and it is not possible to revive it.

The wire that comes up from the armature is very frayed and I think might be the problem that started this whole wild goose chase in the first place.

So I’ll need an alternative. I was looking around and found that a 98 R1 fuel pump has the same upturned inlet and outlet pipes so might be worth a punt as I’d imagine there should be no capacity issue with it.

Anyway, despite going down totally the wrong route as regards the ignition stuff, I’m very happy to have at last narrowed it down to something solvable.

Ah, the joys of classic ownership!

A

UPDATE: Well bugger me with a blunt market garden vegetable!

I just found a germanian site that had a VF1000 fuel pump available for €70 plus shipping!

Way, and indeed, hay! I’m off to do that lottery :slight_smile:

45

Why don’t you just leave it gravity fed or is gravity feed a no no at higher speeds then? The 84/85 VF500s had a pump but this could be converted to gravity feed with no issues at any speed, unless you were racing and then the right hand carb would starve.

46

I actually just had an email back from yer man of Daugherty Motorsport fame, and he said leave it gravity fed without a filter and just keep the tank clean.

Will be doing so till the be pump arrives anyway.

:neutral_face:

47

The VF500 has a fuel filter in the tank and four little filters in the carbs so doing away with an inline filter is no biggy. No idea what the thou has mind. I bought stuff from DMr before. I used his kit to convert the rear wheel on my 500 to 17 inch wheel and got a rear shock off him which I have yet to fit as I have a Hagon which is fine.

48

You need one of these.

http://www.ebay.co.uk/itm/Fuel-Pump-For-Honda-CBR600F-CBR600F2-CBR600F3-CBR600F4-CBR600SJR-CBR600SE-/111538534302?hash=item19f836f79e:g:TpMAAOSwstxVJS18

ONLY use this type of hose.

You need Thick Walled hose so on the tank side, the pump does not suck the hose flat, it also won’t kink or bend that easily so you will need to seat the new pump about 10mm forward in the bracket. I tend to run one of these on a short piece of hose directly from the tank for these reasons.

  1. You can check you have fuel flow. (turn off the tap, watch it empty, open the tap and watch fuel being pulled.)
  2. Dirt ingress prevention.
  3. Easy to clean.

I had exactly the same issues as you have with my Bol. Doing this fixed it and i have had no reoccurrances.

49

Right, I think this is finally sorted.

I got a second hand OEM fuel pump from Germany, and without asking, the sender, an online parts shop, sent on a new set of points for it too, which was nice.

A mate who is an electronic engineer did the little bit of soldering involved and I was ready to rock.

So, I had established that even with gravity feed, the 3 and 4 cylinders seemed to be starved of fuel after a longer run at motorway speeds.

I checked the routing of the lines and the hoses to make sure there were no kinks or harsh bends.

Then, I went back to the original fuel cut-off relay too, from the CBR600 one. I installed the refurbished fuel pump with all the original hoses, though I did use a new fuel filter, noticing that it has a lot less internal surface filter area than the original, but the original did look a bit used so I took then chance.

It started up OK, idled nicely and after about five minutes all four were still purring happily.

On the way to work this morning, it went fine, no drop off, misfire or starvation.

I had a lunch meeting too, and though only a few kms away, it also went fine in this urban distance.

And on the way home too, I kept the pace up just to test things, and all seemed fine.

Fingers crossed, it is now OK.

So, I can only conclude that a combination of a slightly weak pattern pump combined with less than optimum pipework, as in three elbows, was resulting in low delivery to the 3 and 4 cylinders resulting in starvation.

Going back the way in symptoms as to why the fuel pump would cut out, I just don’t know.

But the coils in there are now the best from two sets, so maybe a weak coil, combined with losing the two cylinders on a fuel issue may have resulted in the signal to the cut-off relay being lost or weak, cutting out the pump and then the whole thing grinding to a halt.

Anyway, we live and learn.

On the plus side, though there is a substantial change in the feel of the lever, I like the effect of the Blackbird master cylinder to sharpen the action of the front brakes.

Now I just need to get my CBR wheels powder coated, clad in some modern tyres and fitted with the spacer kit.

UPDATE: Another boringly uneventful run into work this morning in double digit temperatures, wihch is pretty good for late January in Ireland :slight_smile:

Boring reliability would be very nice from now on.

50

Well Ascalon, respect to your determination. It’ll take a few miles to be completely confident in the bike but each mile will make the smile wider and wider I’m sure.

51

well done ascalon, tassi and windy, some good info on fuel pump issues which im sure will help others in the future.

52

good to know its ended well 8)
I like Old Tech its a real challange

53

Have used the bike now all week, in and out to work and out and about to a few meetings and all has been well.

Just to be safe, I’ve run some Redex fuel system cleaner through each tank at fairly high concentration, just in case.

Delighted to have the old battle cruiser sorted.

54

Well, it’s done it again. >:(

Exactly the same symptoms and result. :’(

Last night, I pushed the bike home, as it was late and I was local, but pushing 260kg of recalcitrant VF1000 about 4km is not fun.

After weeks of reliable usage, it just did it all over again.

I am going to have to rip the whole fuel system apart as I thought the OEM fuel pump with new points was the solution on this, but obviously not.

I am thinking the way it stopped this time, that is might be on the supply side of the fuel pump that it is experiencing a blockage.

Question: is there a gauze filter in the fuel valve, the same as the VF750?

The good news is, I got far enough in the shakedown to show that my CBR wheel conversion is good and it handles really nicely on the Pirelli Diablo Stradas and the wider rims. However, the Blackbird master cylinder keeps feeling spongy, despite multiple bleeds. The lever doesn’t have a stroke adjuster, just the span adjuster, so it is hard to dial it out.

Here she is with the front sorted and the rear in but not done up, as I discovered too late in the day that the VF sprocket would not fit the CBR carrier.

iCTUUt.jpg800×594

Needs more rear ride height.

Now, If I can just get the barsteward to run, it would be great!

Any help or advice, greatly appreciated.

55

The symptoms you are having are pretty much identical to GMCC’s ZZR1200.
We traced the problem to poo floating around in no.2 and 3 carb float bowls.
It may also be worth checking the supply from the tank after the bike grinds to a halt.
Are you getting a full stream with the pump supply pipe removed from the tank?
On one Bol I had no fuel came out of the tank until I blew back up the steel pipe with the tap open.
You have eliminated the obvious electrical possibilities,I would suggest that you start at the beginning again with the fuel supply.
PS The Scotland bash would give it a good try out
Regards Bif

56

Thanks Bif,
that is my next plan of action.

I’m going to open up the fuel tap and related gubbins to see if there might be an issue on that side.

I read elsewhere that there are pre-filter screens in the tank, have you any experience of them?

It could well be that rust or crud in the tank is blocking a screen that leaves the fuel pump struggling.

57

So, I think I may have found the issue…

HZP5wo.jpg446×600

There seems to be quite mixture of old crystalised fuel and rust in the tanks, despite the use of protective additives when the bike was dry stoed from 2007 to about 2015.

YY2geJ.jpg446×600

I tried to drain the tank but the last half litre or so simply will not come out and I have a fair amount of crud in there too.

I am going to use the vinegar and salt trick to dry and dissolve away the crap and flush it out.

I’ve use electrolysis on tanks before, on an old ZXR750, and it worked well, but there is only light surface rust in places in the tanks, so I don’t think that level is required. It seems more like old fuel.

This bike came from Germany where the alchohol level of retail fuel has been present for longer, so it has probably been a build up over many years of use, as well as storage.

Still, at least I know there is nothing fundamentally wrong with the bike, that a flush and a bit of agitation won’t cure.

:slight_smile:

58

Small update here.

I spent last weekend trying to flush the tank.

As there is no real direct drain point, it was pain in the arse to remove the sludge and crystalised old fuel.

I put about 3 litres of heavily RedEx enriched fuel in the tank over night, having sloshed it about fairly well. The idea was that the RedEx should dissolve the worst of the solids and then I could flush it out.

When I realised it was not possible to simply turn the tank over drain the fuel, I hit upon the idea of the Mityvac vacuum bleeder pump.

That worked well and I set up three coffee filter funnels to filter the petrol coming out.

So cycled through that about 40 times over the course of about 5 hours. There was still some sediment coming out, but I removed the vast majority of of it.

I cleaned all the fuel lines, flushed the pump and fitted a new fuel filter.

I then ran it for a week with more heavily RedEx concentrations but it would still cough and splutter as it passed 7k rpm, but run perfectly below that.

Today, I managed to remove the carbs and I took each float bowl off individually and gave it a good blast out with air and carb cleaner, right down to removing the main jets and flushing through the emulsion tubes. There was a lot of old rust and varnish deposits in the float bowls and it took some flushing to get rid of it all.

I then had the fun of refitting the carbs :slight_smile:

I feel, having accomplished that, that I have had some sort of right of passage—I have fitted the carbs to a V-Four!

You’re never the same after that :wink:

Hopefully, that is it sorted now and she will sing through the top end too.

It’s been a bit of a haul, but at least I feel I have gotten to know the bike well now, and bar gear box dismantling, there’s little I wouldn’t tackle.

Oh, and electrics—I hate electrics :slight_smile:

So, it fired up after putting it all back together and ran smoothly, but I haven’t take it out for a spin yet. I’ll do that tomorrow.

59

these bikes are not for the timid 8) :slight_smile: :’( :o >:( :slight_smile: :slight_smile: :slight_smile:

60

I recently also had my “right of passage” with these carbs, I know what you mean, they can be frustrating but satisfying in the end.