Gas tank swap?

[Arnie]

Someone needs to work out all the details. For the fuel pump conversion. And post it up so, I can convert my 86 over to a pump.
I'm so sick of having to clean out tiny bits of varnish that get in my carbs every couple hundred miles. I've cleaned the tank out three times. But it still keeps happening. 

Yes, and that someone is YOU.  All the information has been posted a number of times under various topic headings.
Stop being so lazy, expecting others to do the work for you.
Put it all  together.  Then post it for others.

Arnie

[giantkiller]

No hijack just joining in on fuel pump conversion talk. I tried a filter, could only get about 2 gallons out! Of the tank. Before! It would run low in the float bowls and stall. First time in Chicago rush hour traffic.

I did a manual petcock on my 86 I just folded the screen over on the upper vent on the side panel for access

[giantkiller]

Not lazy just too many other projects going on right now, working on better fork extensions for gsxr front conversion

[aviationfred]

I have a 89'/90' tank on my 87'. Currently I have a small ball valve inline on the fuel line to turn the fuel off when not running. The bike came this way from the previous owner. I have found a vacuum actuated fuel pump that I am going to purchase. This may be an option for you and other members.

http://www.fjcatalogue.com/catalog/item/7220095/7430748.htm



Fred

[movenon]

I have a 89'/90' tank on my 87'. Currently I have a small ball valve inline on the fuel line to turn the fuel off when not running. The bike came this way from the previous owner. I have found a vacuum actuated fuel pump that I am going to purchase. This may be an option for you and other members.

http://www.fjcatalogue.com/catalog/item/7220095/7430748.htm



Fred

Let us know how that pump turns out. I have seen them but haven't been able to see any spec's. beyond the pump rate. Had a street rod with vacuum wipers once, ran pretty good when I got off the throttle at high vacuum 

[Pat Conlon]

I like how the electric pump on my '92 starts filling the bowls the moment I turn the key on...before I start the engine (before any engine vacuum)

Sure makes start up a snap.

[Paul1965]

I have a 89'/90' tank on my 87'. Currently I have a small ball valve inline on the fuel line to turn the fuel off when not running. The bike came this way from the previous owner. I have found a vacuum actuated fuel pump that I am going to purchase. This may be an option for you and other members.

http://www.fjcatalogue.com/catalog/item/7220095/7430748.htm



Fred

Thanks for the link Fred. I'm going to take a good look at modifying the 90 tank to accept my 84 petcock though first and go from there. If I can enlarge the opening and still properly secure the petcock without any leaks, I'm more than happy with a gravity fed fuel supply. The bike is at the body shop for some light body work then a respray over the winter, so I've got plenty of time to make something work 

[Paul1965]

Well, I flipped both tanks over and pulled the petcocks to do a comparison.  As I suspected, there is no easy way to make the 84 work in the 90 tank. While the mounting boss is the same size, the mounting nuts are an integral part of the tank being welded on the inside. Also, even if I could enlarge the smaller opening, there's not enough metal to be able to drill and tap a new hole to bolt the larger petcock in.




So my next question is this: If I go the route of installing a fuel pump that's rated at 2.5-4.5 GPH (http://www.ebay.com/itm/281195195463?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649), what risk do I run if I don't swap over the needle and seats? I have absolutely no issues doing the fuel pump install, but I haven't had a carb apart in years let alone 4 of them!

[Pat Conlon]

You will risk flooding your bike.
Short answer: The float needle wll not be able to close due to the higher system pressure exerted by the pump.
Background: The floats exert only a certain amount of pressure on the float needle and that needle mates with the seat to shut off the gas. The gravity flow fuel system uses a larger diameter opening in the needle seat because the system pressure is lower than the fuel pump system. The fuel pump system has a higher line pressure than the gravity flow, and uses a smaller diameter float needle seat opening.
Pressurized fuel (via fuel pump) flowing thru the larger diameter opening in the needle seat can overwhelm the float needle, holding the needle off the seat, causing flooding.
We have had forum members use the small (fuel pump) needle seats on lower pressure gravity flow applications but never the opposite, large needle seats on a fuel pump.

Float needle seats are cheap and easy to install....just do it, besides, should be ready for new needle seat O rings anyway.

For me....the jury is out on that eBay fuel pump.  Why don't you follow George's recommendation?

[Paul1965]

You will risk flooding your bike.
Short answer: The float needle wll not be able to close due to the higher system pressure exerted by the pump.
Background: The floats exert only a certain amount of pressure on the float needle and that needle mates with the seat to shut off the gas. The gravity flow fuel system uses a larger diameter opening in the needle seat because the system pressure is lower than the fuel pump system. The fuel pump system has a higher line pressure than the gravity flow, and uses a smaller diameter float needle seat opening.
Pressurized fuel (via fuel pump) flowing thru the larger diameter opening in the needle seat can overwhelm the float needle, holding the needle off the seat, causing flooding.
We have had forum members use the small (fuel pump) needle seats on lower pressure gravity flow applications but never the opposite, large needle seats on a fuel pump.

Float needle seats are cheap and easy to install....just do it, besides, should be ready for new needle seat O rings anyway.

For me....the jury is out on that eBay fuel pump.  Why don't you follow George's recommendation?

I was talking to the Flying Scottsman about this and figured flooding would be an issue, as the bike can't burn all the gas the pump would be supplying. As far as following George's recommendation, I guess I haven't because I haven't really figured out what the hell I want to do yet 

I really want to use the 90 tank yet I need to keep things within budget.

[movenon]

It's not to hard to change out the needle and seats. Change out the O rings. I have a few Viton Orings (7.1 x 1.6mm) if you need 4 let me know I will send you 4. What else you going to do this winter? That's a killer price on that pump Paul. I wonder about what appears to be the plastic output nipple.
George

[Paul1965]

It's not to hard to change out the needle and seats. Change out the O rings. I have a few Viton Orings (7.1 x 1.6mm) if you need 4 let me know I will send you 4. What else you going to do this winter? That's a killer price on that pump Paul. I wonder about what appears to be the plastic output nipple.
George

Hey George. No doubt that's a good price, but of course the question is what kind of quality is it. I've also got this one I'm watching that's at least all metal http://www.ebay.com/itm/200876052936?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649. I found a set of needles and seats for around $50 shipped, but then I also found a Facet 40106 pump that only flows under 2.5 PSI at 17 GPH, so I'm wondering if that wouldn't work with my stock carb setup. I looked around for the vacuum fuel pump you linked to earlier, but they're all overseas. I'm hesitant to buy like that because generally if you have a problem, you're up that well know creek without a paddle. At least I have all winter to get a handle on what I want to do. However the longer I take to get the tank working the longer it will be before the FJ is all painted 

[movenon]

It's not to hard to change out the needle and seats. Change out the O rings. I have a few Viton Orings (7.1 x 1.6mm) if you need 4 let me know I will send you 4. What else you going to do this winter? That's a killer price on that pump Paul. I wonder about what appears to be the plastic output nipple.
George

Hey George. No doubt that's a good price, but of course the question is what kind of quality is it. I've also got this one I'm watching that's at least all metal http://www.ebay.com/itm/200876052936?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649. I found a set of needles and seats for around $50 shipped, but then I also found a Facet 40106 pump that only flows under 2.5 PSI at 17 GPH, so I'm wondering if that wouldn't work with my stock carb setup. I looked around for the vacuum fuel pump you linked to earlier, but they're all overseas. I'm hesitant to buy like that because generally if you have a problem, you're up that well know creek without a paddle. At least I have all winter to get a handle on what I want to do. However the longer I take to get the tank working the longer it will be before the FJ is all painted  

I know about projects.... Check the spec's on the Facet 40106... http://www.facet-purolator.com/cube-fuel-pumps.php  The pump needs to shut off fuel flow with no power on it. It's an important feature. You can't or shouldn't rely on the needle and seats to do that job. Look at the 40717 spec.

Here is a Facet Posi-Flo spec sheet http://www.facet-purolator.com/posi-flo-pumps.php check out the 60300.

Also RPM's pump http://www.rpmracingca.com/proddetail.asp?prod=fuelsystem%3AFP. Make sure it has the fuel shut off feature.

As a note NAPA can get and sometimes stock Facet pumps. Cheaper on line but on the road its nice to know.

Read this thread http://www.fjowners.com/index.php?topic=9724.0
George

[Flying Scotsman]

Paul I have a box of carb parts in my garage I might have the n/s you need.If nothing else you could look at them and see whats up.I hope to be pulling the engine out of the Civic in the next few days I think I have a buyer for it.I can help you with your carbs if you need help but im sure you can do it once you take a look at them.I know where to get mikuni parts in elgin if need be as well.I have bought jets there a couple of times.

[Paul1965]

Paul I have a box of carb parts in my garage I might have the n/s you need.If nothing else you could look at them and see whats up.I hope to be pulling the engine out of the Civic in the next few days I think I have a buyer for it.I can help you with your carbs if you need help but im sure you can do it once you take a look at them.I know where to get mikuni parts in elgin if need be as well.I have bought jets there a couple of times.

Thanks Scott, I think I saw that box of parts lol...If you need some help pulling the engine let me know.

George, thanks for the reminder on the shut-off. Having been in the automotive field for 30+ plus years, I'm use to a fuel pump that stops when you kill the ignition.