Adding a fuel pump to my 89

[oldktmdude]

Pretty sure I ran RS36's and RS38's on my 89 with no issues at all with the seats they came with.  Same with the FCR's. 

I'd try it first and see if there even is a problem before trying to solve a problem that's probably not going to be there!

I have RS38's and they can not hold the pump pressure with the float valves that come standard with them.

[fj1289]

Pretty sure I ran RS36's and RS38's on my 89 with no issues at all with the seats they came with.  Same with the FCR's. 

I'd try it first and see if there even is a problem before trying to solve a problem that's probably not going to be there!

I have RS38's and they can not hold the pump pressure with the float valves that come standard with them.

Thanks for clarifying - it's been several years and my memory must be a bit faulty!

[melloncollie]

I was going to try as is at one point but got talked out of it from everyone's suggestions.  The new 2.0 mm seats are in and ready to go. 

Don't know what fuel pump they have in mind for you but be sure the fuel pump completely shuts off the flow fuel when the pump is powered off*** ..if it doesn't and you get some dirt or debris under any float needle seat, you will awake one morning and your crankcase will be full of fuel. 

***....or if the pump does not stop the fuel flow you can always put a 12v inline fuel shutoff solenoid keyed to your ignition switch.

I didn't talk specifics with Sudco.  The pump I ordered is off a YZF600, used.  Buying a used electrical part goes against a lot of what I used to tell my customers; we'll see if it bites me.  My understanding (from an old bit of info) was that the YZF600 will be a drop in replacement.  I really wanted it to be a brainless solution: buy the pump and plug it in.  If it doesn't work out so be it.

[melloncollie]

Okay, got a few things done in the past few days.  I was a little bummed I didn't get everything shipped by the weekend but I forgot our local music festival was going on.  So it worked out.  I got to see Steve Miller, Modest Mouse, Jason Isbell, Dillon Francis, Steve Aoki, and Violent Femmes; among others.

Some pictures of the needles/seats installed the other day.  The RS sets come bare; no o-rings or screens.  Mikuni P/N KV/10 for the o-ring and VM18/233 for the screen.  I swapped the screens over, no issue there.  Figured I'd get new o-rings because I'd be pissed if I broke one and had to wait.



2.0 Seat



Pump went in next, off a YZF600.  Smelled like not-fresh gas, maybe seafoam?  Wasn't sure if that was good or bad.  Info for it said 21k miles but it is 20 years old at this point.  I was able to use the YZF bracket, bolted right up.  It even came with the hardware which was awesome.



The moment of truth: turned the key to prime it and... nothing.  Got some alligator clips and put power directly to the pump and it pumped!  That's good.  Put some gas through it for good measure.  Plugged it back in and started going through some troubleshooting in my head until I realized I left my kill switch on.  Good thing I didn't get too far.  Turned the key again and this time it worked!  Filled the carbs and checked for leaks; everything seemed fine.  Seems like Dan was on to something; so far everything's working like its supposed to with the smaller seats in.  On to the clutch.

Side question: what's the plug shown under the fuel pump?  It sits right behind the pump normally, I pulled it out to get it in the picture.  Nothing's plugged into it right now. 

Clutch and detent kit were straight forward.  I had the one new wide disc soaking in oil while I did the pump and detent kit.  I ended up taking the shift shaft out to make the detent install easier since I already drained the oil earlier.  Everything went as expected except for installing the old spring the first time.  Whoops. Pulled it back off and got the new one on. 



My wire clip came out in one piece earlier but I tossed it to the side.  Put the friction and steels back in (also removing the narrow inner plate, inner spring, spring seat, and adding the wide disc), doubled the spring, torqued everything down, filled the oil and fired it up.  I also installed new exhaust gaskets over the weekend.  I think they were leaking because I hastily reused them with my new exhaust this spring.  Its better now but I think its still leaking somewhere.  My next guess is a slip joint below the bike but we'll see.

First impression: the clutch lever is a lot stiffer with the double spring.  And it engages closer to the bars which I'm sure I'll get used to.  I figure I'll eventually do something about the heavy lever, but for now it seems okay.  That'll be a good excuse for a future project anyway.  For now everything works and the weather's beautiful so I'm going for a ride.

[melloncollie]

Well after 500 miles yesterday and sitting overnight everything still works and nothing's leaking.  Clutch lever softened up just a little bit.  It shifts better (quicker, smoother) with the detent kit, happy with that purchase.  One thing I forgot to mention; I kept my fuel line T when I installed the pump, so two lines going into the carbs.  When researching the pump I saw a post (I think from Randy) saying it doesn't matter if the carbs have a single or dual fuel feed.  I can't find it for the life of me now.  So far it works for me.

[giantkiller]

Cool. Good to hear.

[melloncollie]

Dang, seems like I jinxed myself.  Briefly left it idling today at the end of my driveway and came back to a wet spot on the ground, gas leak while it was running.  Upon further investigation all four carbs pour gas out the overflow on the side stand.  When the bike's propped up (no center stand) they remain leak free.  Going to take the carbs off tonight to make sure floats aren't hung up and that the seats are free of debris. 

Anyone else have thoughts or suggestions on this?  When I park in the garage I keep a block of wood under the side stand, so I think that explains why it didn't leak last night.

[Pat Conlon]

Yep, check your float needles for junk, look at your filter......did you mention that you have a Kreem coated tank?
If so, you may want to investigate that...

Set your float height to the minimum.

[melloncollie]

No dice.  Carbs looked spotless inside, cleaned them out anyway.  There's not really a range for the float height for these, its 17mm +/- 1mm.  So I set them to 18mm.  Same as before: leaks when on the side stand and not when propped up/level.  I'm thinking I'll keep going in the same direction with the float height to see if it eventually stops. 

Yep, check your float needles for junk, look at your filter......did you mention that you have a Kreem coated tank?
If so, you may want to investigate that...

Set your float height to the minimum.

When you say set to minimum you mean fuel level minimum, float height maximum?  More float height, since they're upside down, means less fuel right?  Or am I missing something.  And no kreem in my tank.

[Pat Conlon]

Yes, the minimum float level is the maximum distance measured from the gasket base on the carb body.

Try 1-2 mm lower than spec.....see if that helps.
You have a fuel pump quickly refilling the bowls so I wouldn't be as worried with the lower float level like I would with a slower gravity flow fill.

I'll let the RS experts Travis, Chris and KTM Peter chime in....

[Waiex191]

I'm having similar issues - spotless carbs but they leak.  All new orings and needles.  I'm going to try a set of K&L needles.

[Pat Conlon]

Have you guys seen this? https://fjowners.com/index.php?topic=7056.0
(This is applicable to the oem FJ BS36CV's not for the RS flatslides)

As we raise up our rear ends to get more weight on the front tire, the fuel level slightly changes in the bowls. The front edge of the fuel bowl the fuel level is slightly higher and can cover the vent opening in the pick up tube.
This blockage of the vent can contribute to a siphon action happening thru the choke vents.
Drilling this extra vent hole well above the fuel level prevents the vent blockage by fuel and thus breaks the siphon.
That's the idea as I understand it.....

[Waiex191]

My FJ is mostly stock - but maybe my float level is too high.  Could be over the stock vent hole as Randy pointed out.

[T Legg]

I have no experience with pressurized fuel but I would bypass the fuel pump and see if they still leak . If they don't I would try the 1.5 mm needle valves that  oldktmdude is using .

[Waiex191]

I have no experience with pressurized fuel but I would bypass the fuel pump and see if they still leak . If they don't I would try the 1.5 mm needle valves that  oldktmdude is using .

Mine leaks overnight with the pump off.