Flooding carb

[Dan88]

Hi guys and gals, First off, sorry to ask a question that has already been covered in other blogs.
Carbs Flooding - A bit of history.  I removed the carbs and took them into the Yamaha shop to be checked and cleaned about a year ago, now come forward a year and I want to get her out for a ride. So yesterday I got her running after much effort! Synchronized the carbs took it for a run round the block but it was running rich and lacking in power. Fuel then started running out somewhere from underneath the carbs.  I was reading a thread the other day and someone had a suggestion for fixing carbs that are "FLOODING" which did not involve removing the them in the first instance. I've tried to find it but have had no luck
Can anyone help with this problem? If I have to remove the carbs so be it! But if there is a simple step 1 solution that I can try first, then that is were I would prefer to start. 

Thanks in advance for all the great advise offered.

Dan

[jscgdunn]

If In understand the dealer cleaned/rebuilt the carbs a year ago and you just installed?  Did the dealer install new needle and seat valves?

Just to be clear, what do you mean by synchronized carbs?  How did you do it?

Jeff

[Dan88]

Hi Jeff, the dealer only  inspected and cleaned the carbs, no new needles or valves.

I used a vacuum gauge kit to sync the carbs.

I've now just cleaned and re-gaped the plugs, adjusted the fuel mixture screws back to factory setting of 2.5 turns out. They were 3 turns out.
The engine is now revving up like it has its full power back, but the carbs are still flooding. I can't see which one it's coming from though either.

Dan 

[jscgdunn]

Ok they are most likely leaking because the needle and seat valve on one (maybe more) is stuck.  Try tapping each float bowl with a screwdriver...it might work.  Even with one stuck it will run poorly.

It could also be the floats are out of adjustment, which would require carb removal to check float height.


Jeff

[Dan88]

Ok thanks, I'll give it a go.

Dan

[simi_ed]

A most likely cause is the o-rings around the needle seats have failed, allowing gas to bypass the needle/seat/float Assy. 
The best cure is to buy Randy's ~$20 SS screw kit that includes he needed o-rings replace the screws and prongs and that'll likely fix your problem.

[fj1289]

Another possibility if it is not a stuck float is the o-rings around the needle seats are dried out and not sealing.   A very common issue with these bikes as they get older.  And not something that always gets replaced during a cleaning.  

This kit is a good deal - replaces all the o-rings and the easy to strip hardware:

http://rpmracingca.com/proddetail.asp?prod=carbkit

[fj1289]

Get out my head Ed!  I'm slow on this phone

[simi_ed]

Not trying, gave it a while. I thought I heard someone saying 'o-rings' ... I guess it was you, Chris!

[Dan88]

Hey Guys, tapped the bowls and flooding stopped temporarily then came back. So carbs off and into it!! Any idea's best place to get needle's and seat valves?
And do you suggest doing all carbs or just the guilty one?
Dan

[simi_ed]

Dan, you probably DON'T need needles & floats, just the o-rings http://rpmracingca.com/proddetail.asp?prod=carbkit&cat=24 and screws. The stainless screws are icing on the cake for the NEXT TIME you have to go into the carbs.
Hint: if you keep riding a FJ, you'll be into the carbs.  Will anyone here dispute that?

[X-Ray]

One thing I just did with the '94 I just bought is to blow back up the overflow tube from the carb that is leaking. I noticed fuel piddling out when I wheeled it out of the shed, so grabbed the tube and blew back into the suspect carb, and the leaking stopped. Someone told me about this trick a while back, doesn't work all the time though .

[racerrad8]

You have a few different choices if you believe the needle and seats are leaking

1) Replace the old seats with new ones depending if you are looking for genuine Yamaha or aftermarket and if the bike is fuel pump or gravity fed RPM has you covered
Fuel Pump:
Needle & Seat Assy (1.5)(F/Pump)
Needle & Seat Assy (1.5)(F/Pump) OEM Yamaha
Gravity Feed:
Needle & Seat Assy (2.3) (Gravity)
Needle & Seat Assy (2.3) (Gravity) OEM Yamaha


2) You can try to change the o-rings and the needles only
84+ FJ11/12, XJR1300 Mikuni BS36 Float Needle
Needle Seat O-Ring Set

3) Try and change only the o-rings

Needle Seat O-Ring Set

Changing one or all will depend if you feel like pulling the carbs off again if the others are also bad and you only changed the one.

And as previously stated it would also be a good idea to get rid of the soft JIS screws and replace with the FJ11-12/XJ12/XJR13 S/S Screw & O-Ring Carburetor Kit which includes to needle and seat o-rings. It will save you a few choice words after the JIS screws turn to mush with your phillips screwdriver.

Robert - RPM

[Dan88]

Thanks guys. I'll go with Ed's idea and replace the O rings and screws. Let ya know how I get on in a couple of weeks.

Dan

[movenon]

There is an easier and harder way to remove the carbs  .  If you are not aware of it remove the two upper bolts holding the rear sub frame, unbolt the air box and rotate (push down) on the rear sub frame. It will give you more clearance.
George