Got lucky today

Posted: Tue May 24, 2016 9:57 pm

A tale of why the automatic fuel valves (AFV) aren't such a bad idea.

I have an 1100f with a CBR900RR swingarm so it lacks a center stand and often lives on the side stand. It also has CR33 carbs (rebuilt 2 years ago and does not have an AFV) and the bike has a recently rebuilt petcock.

Rode it yesterday for about 80 miles, filled it up with gas, and parked it with the petcock in the OFF position, or so I thought. Came back this AM to take it out again and see some fluid on the floor but not anywhere I would expect a leak. It is a slimy yellow, not oil but more like an oil/gas mixture that dripped off the left cylinder fins. I look at the petcock to see why and I notice that it is nearly off but not perfectly in the off position (we are talking a few degrees off horizontal).

Pull the plugs and run the starter and sure enough #1 is filled with gas. Ended up doing an oil change as the fuel tank was visibly down and now all is well but yesterday the gremlins conspired to make a full fuel tank (maximum fuel pressure), a 2 month old petcock in the nearly off position, and 2 year old needle valves create a potential hydrolock condition.

I might be the only fan of the AFV here on the site so I rebuild them to make sure they work as intended, just need to purchase a new rubber diaphragm and you are good for another 20 years. For this bike I think I will look at replacing the CR seats/needle valves and finding an inline shutoff that I can run off the ignition.

Posted: Wed May 25, 2016 1:08 am

sillygoose wrote:

...For this bike I think I will look at replacing the CR seats/needle valves and finding an inline shutoff that I can run off the ignition.

Nice idea. Please take some pictures and do a write-up?

Tx,
Bill

Posted: Wed May 25, 2016 1:25 am

My auto cock has worked reliably for 35 years.
I am interested in where you get the replacement diaphragm from.

Posted: Wed May 25, 2016 1:34 am

I removed my AFV years ago but am in the habit of looking at the petcock each time to make sure it is dead center off.

CB1100F Joined: Feb 17, 2009 Posts: 2105 Location: Oz

thx113 wrote:

My auto cock has worked reliably for 35 years.

I'm letting that one through to the keeper... Laughing

Posted: Wed May 25, 2016 3:02 am

I have been banging on about using an electric shut off for years but nobody listens and you can get them for under $20 and then you only use the petcock for reserve

Posted: Wed May 25, 2016 4:15 am

norm wrote:

I have been banging on about using an electric shut off for years but nobody listens and you can get them for under $20 and then you only use the petcock for reserve

I never picked up on this before but I'm very interested as I have a problem with my CBX (forgetting to turn it off) and this could be a perfect solution.
Is it possible for you to explain what you used and how you fitted it, or in fact any details at all would be appreciated.

Captain

Posted: Wed May 25, 2016 4:47 am

thx113 wrote:

My auto cock has worked reliably for 35 years.

Maybe I'm in the wrong forum...

I'll just check another thread out...

Posted: Wed May 25, 2016 4:57 am

Here is the solonoid valve I use, I have fitted them to a number of bikes, this one is 1/4", you can go to 3/8" if you need more fuel delivery but I have never had the need. They of course cost a bit more.
http://www.ebay.com.au/itm/121846176641?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Fit it wherever you can under the seat or tank and pick up the power for it from the rear brake power supply

Posted: Wed May 25, 2016 5:16 am

I've actually considered not only a shut off, but also a low pressure fuel pump, would be very handy with a decent fuel filter.

With just the gravity feed, a bit of uphill fuel line can create an air bubble trap that hinders fuel flow, and can be a royal PITA.

I think a combination electric fuel pump/safety shut off with a fuel filter would be cool.

Posted: Wed May 25, 2016 5:17 am

I've actually considered not only a shut off, but also a low pressure fuel pump...

With just the gravity feed, a bit of uphill fuel line can create an air bubble trap that hinders fuel flow, and can be a royal PITA for fuel delivery.

I think a combination low pressure electric fuel pump/safety shut off with a fuel filter would be cool.

Posted: Wed May 25, 2016 6:23 am

Gene, I did that with my VFR, but then you also need to fit a fuel pump isolator so that if the motor stops and the ignition is still on the fuel pump stops pumping fuel. Very easy using a carmtrol sensor from a plug wire but it all gets a bit bulky and there isn't a lot of room to play with. I have never suffered from an airlock on mine and been running it that way for probably 10 years

Hawk Joined: Aug 17, 2013 Posts: 302 Location: Devon. UK

If you used a DPST relay when doing the coil relay mod then is there any reason you can't use the spare terminal on that relay to power the fuel shut off valve?

After all, both the ign coils and the fuel valve would need to be energised at the same time in order for the bike to run

It would save space without needing to fit an extra relay, all you would need is the extra wiring from the relay to the fuel valve and an earth.

Posted: Wed May 25, 2016 7:28 am

The only reason the early VFR's had to run a fuel pump was because the bottom half of the tank was lower that the carbs

Posted: Wed May 25, 2016 8:32 am

Seems like a shit hot idea Norm. Glad you raised it again, I've copied the add as a reminder for when I'm at that stage. beerchug

Posted: Wed May 25, 2016 9:29 am

Stueecat wrote:

If you used a DPST relay when doing the coil relay mod then is there any reason you can't use the spare terminal on that relay to power the fuel shut off valve?

After all, both the ign coils and the fuel valve would need to be energised at the same time in order for the bike to run

It would save space without needing to fit an extra relay, all you would need is the extra wiring from the relay to the fuel valve and an earth.

Cunning plan ...!

Regards,

Max

Posted: Wed May 25, 2016 12:02 pm

I too am curious about where to get the diaphragm from. Is there not 2. An under and over. One with a hole in it?
Eric.

Posted: Wed May 25, 2016 12:34 pm

genesound wrote:

I've actually considered not only a shut off, but also a low pressure fuel pump...

With just the gravity feed, a bit of uphill fuel line can create an air bubble trap that hinders fuel flow, and can be a royal PITA for fuel delivery.

I think a combination low pressure electric fuel pump/safety shut off with a fuel filter would be cool.

I like this idea. Mike Nixon has told me multiple times that the auto petcock is a hindrance to cold starting and to ditch it. A low pressure pump delivering some fuels to the bowls might help a bike start faster - especially if it's been sitting for a couple of weeks.

Hawk Joined: Jan 10, 2012 Posts: 439 Location: Chicago

I've removed the AFV on all my F bikes and am extremely careful to turn off the petcock after each ride......Along with have a reliable new one too...

E

Posted: Wed May 25, 2016 2:23 pm

I have the afv on my 900 but seriously question if you need it. Whenever I have experienced a flooding carb even with the bike on the side stand the gas comes out the drain tube from the carb and does not flood high enough to go into the cylinder. On a cbx however I have seen the drain tube from #1,2 and 3 carbs go across to the center of the bank and when on the side stand this point is above the level of the inlet stalk into the head on 1 So the only place for the gas to go is into the cylinder. I think the wide carb bank and drain tube routing may explain why this is a big issue on cbx's. On F's with standard carbs just make sure the drains are not blocked and the tubes all run downhill. Also of note, in the UK the afv only showed up on later model 900's, I think only 82 and 83.

Posted: Wed May 25, 2016 3:49 pm

thx113 wrote:

My auto cock has worked reliably for 35 years.
I am interested in where you get the replacement diaphragm from.

Time for a refresh then. This is what you need (new is on the bottom):

You reuse the fuel taps, everything can be replaced if you like. The AFV diaphragm kit is 16953-ME5-025, about $25 from Honda.

Posted: Wed May 25, 2016 4:37 pm

tomk1960 wrote:

Mike Nixon has told me multiple times that the auto petcock is a hindrance to cold starting and to ditch it.

It has nothing to do with cold starting and everything to do with no fuel in the bowls after a long sit.

You can blow in the vent tube to fill the bowls if you have to or I heard of some using a squeeze bulb for the same effect.

Posted: Wed May 25, 2016 4:53 pm

sillygoose wrote:

tomk1960 wrote:

Mike Nixon has told me multiple times that the auto petcock is a hindrance to cold starting and to ditch it.

It has nothing to do with cold starting and everything to do with no fuel in the bowls after a long sit.

You can blow in the vent tube to fill the bowls if you have to or I heard of some using a squeeze bulb for the same effect.

I have a syringe that fits the vent hose which I use for exactly that purpose on my 82 900. My 83 R is not fitted with the vacuum pet cock so that I just turn on a wait a few secs for the bowls to fill.

Posted: Wed May 25, 2016 5:31 pm

Nice nice idea on using a syringe.

The problem with the CR33s is not only is there no AFV but there is no bowl overflow drains either. Sad

Posted: Wed May 25, 2016 5:46 pm

As J.R. likes to say "Turn the petcock off before you shut it down and run the fuel out of the bowls". All these problems are solved.

Posted: Wed May 25, 2016 5:57 pm

norm wrote:

Here is the solonoid valve I use, I have fitted them to a number of bikes, this one is 1/4", you can go to 3/8" if you need more fuel delivery but I have never had the need. They of course cost a bit more.
http://www.ebay.com.au/itm/121846176641?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Fit it wherever you can under the seat or tank and pick up the power for it from the rear brake power supply

I think I will have to run some tests. I checked some on Amazon but the reviews are filled with complaints about being hot to the touch and failing after extended operation, some of these seem to draw 1.4A all the time.

Then there is this beauty, a 3/8" ball valve so no flow restriction and just 300ma opening current and just 30ma to keep it open. The downside is it is a $50 shutoff but hey, I just spent half of that replacing the fouled oil in the bike.

http://r.ebay.com/L7i9BC

I'll pick something up and test flow rates and current draw as well as sort out what mounting options I have.

Posted: Wed May 25, 2016 5:59 pm

sillygoose wrote:

You can blow in the vent tube to fill the bowls if you have to or I heard of some using a squeeze bulb for the same effect.

I wish that method worked, but it never has for me with either of my F's. Maybe the squeeze bulb would do the trick, but hasf anyone here has ever tried that? I think Mike recommends removing it because the bowls take even longer to refill with it in place.

Posted: Wed May 25, 2016 6:04 pm

1100russ wrote:

As J.R. likes to say "Turn the petcock off before you shut it down and run the fuel out of the bowls". All these problems are solved.

My petcock was shut off, I just had some small parallax error confirming it looking at it on side stand.

I plan to characterize this petcock and make some marks where the flow is really off and use those to set the petcock position. I think I have a recent OE petcock as well to compare in case these petcock rebuild kits have a slightly different shutoff region around the OFF position (I think they are using a Yamaha shutoff gasket).

Posted: Wed May 25, 2016 6:41 pm

sillygoose wrote:

1100russ wrote:

As J.R. likes to say "Turn the petcock off before you shut it down and run the fuel out of the bowls". All these problems are solved.

My petcock was shut off, I just had some small parallax error confirming it looking at it on side stand.

I plan to characterize this petcock and make some marks where the flow is really off and use those to set the petcock position. I think I have a recent OE petcock as well to compare in case these petcock rebuild kits have a slightly different shutoff region around the OFF position (I think they are using a Yamaha shutoff gasket).

But your bowls weren't empty.

Edit: and if by chance your petcock either leaks or is not completely shut your bike will just keep running. Simple is good.....

Posted: Wed May 25, 2016 7:34 pm

I think I will have to run some tests. I checked some on Amazon but the reviews are filled with complaints about being hot to the touch and failing after extended operation, some of these seem to draw 1.4A all the time.

Must admit I have never even thought about it getting hot, maybe I should check it one day but as this one has worked for years I'm not too fazed