Carb O-Rings

[ozzstar]

I've been told that the O-rings in the FJ carbs are 'metric' in size.  My question is does anyone know what size the orings are?  There are the: (#1) needle seat oring, (#2) the plastic connectors between the carbs , which i think there are a total of 12 0-rings, including what looks like some kind of overflow plastic T connector? There are 2 silver colored fuel connectors x4=8 , then the other 2 white/pinkish T connectors x2=4  Am i leaving out any other carb o-rings?? 

I would like to find a source to buy all these O-rings anywhere but the dealer.  They want something crazy like $3-4 a piece!!  Highway robbery in my opinion.

I tried emailing David Raforth a couple of times and unfortunetly had no response back in the last couple of weeks. 

Thanks for your help. 

[gdml2]

Top carb is later style (fuel pump fed - 1989 and up I believe)  Single center feed inlet c/w 2 transfer tubes and 1.5 size float needle seats.
Bottom carb is early style ('84-'87 gravity fed) dual inlet tees and 2.3 size float needle seats.



Later style carbs.

Hope this helps.

Greg

[mikeholzer]

That's a pretty impressive response! Nicely done.

[ozzstar]

Thank YOU!!

Ozz

[ozzstar]

Note: Will add captions when I get a few minutes.

Greg

[/quote]

Hi Greg, great info. 

The plastic white T fittings seem to just point downwards when installed  When i removed the carbs from my bike nothing was attached to them.  Should there be some type of hose or tubing?  Seems to me that foreign debris could get into the carbs if the T fittings are just left 'open'.  Thanks again

Ozz

[gdml2]

Sorry guys, Up to my ass in alligators here 

I realize those little O rings add up, but I wouldn't recommend a cheap replacement.  These things have to withstand the effects of heat and contact with fuel.  The factory ones are very good at that - will last for years (just remember how old these bikes now are).  You don't want to gamble with leaky carbs and resulting fire for the sake of a few dollars.  Save that money somewhere else.  I either get my stuff from the local Yamaha dealer, Sudco, or more recently, I'm getting most of my stuff from Hank Scott (Hank Scott Racing - see his website - great service, good prices).  You're going to pay somewhere between $3.00 - $6.00 wherever you get 'em.  Please note: those O ring measurements are quick measurements I made with my calipers, they are not out of a book.  Those white plastic Tees are overflow tees.  Yes, they do point down, and from the factory they have a length of hose on them to direct any fuel from an overflow down away from the hot motor.  The other smaller hose are bowl vent hoses.  Check them carefully for kinks as it is quite common for one or two of them to be restricted, which really confuses the metering system in the carbs. 

Greg

[SlowOldGuy]

Needle seat O-rings are 7mm ID x 1.5mm cross section.  I use a slightly oversized 7.1 x 1.6 O-ring in my kit for a tighter seal.

The fuel transfer tube size is 6mm ID x 2mm cross section

The idle mixture screw size is 3mm ID x 1mm x-sec.

Sorry, I've been out of touch lately with surgery and doctors appointments and can't get to my normal email address.  If you still want one of my carb kits then email me at RAFORTHDL@aol.com with your mailing address.

DavidR.

[SlowOldGuy]

...  The other smaller hose are bowl vent hoses.  Check them carefully for kinks as it is quite common for one or two of them to be restricted, which really confuses the metering system in the carbs. 

Nope, nice try, the bowls are vented by the large T fittings.  Those 4 small hoses are actually air intakes for the choke circuit.  I think the maintenance archives were pulled over from Yahoo.  Look there for detailed descriptions of the carbs operation, the metering circuits and tuning tips.

DavidR.

[Dan Filetti]

Good to see you posting, David.  Been hoping things work out for you.

Take it easy,

Dan

[SlowOldGuy]

Thanks Dan!
Got 40+ staples out of my neck last Thursday.  Still quite a bit of pain in the nerves surrounding the incision area, but fortunately the incision itself is still totally numb (but the doc says the feeling will return in a few weeks).

Unfortunately, the easy part may be behind me.  They took 17 lymph nodes out of my neck(!!).  I had no idea there were that many.  Only one (the LARGE 5cm one) had any cancer cells in it. Maybe they should have left a few to continue the fight (if necessary, but then I'm not a Dr.).

Anyway, I begin radiation and chemo next week (for 6 weeks) and the side effects of that treatment make the surgery seem like a mosquito bite.  Not looking forward to it at all.

But the good news is there is still no primary tumor, so the rad and chemo should eliminate any future occurrence

DavidR.

Oh yeah, the really bad news:  I had to cancel my plane ticket to Atlanta for the rally.  Cost me $150 to cancel a $169 ticket (thank you American).  :-(
Should have gone and just hung out, but too many appointments.

[gdml2]

David, thanks for clearing that up. 

Greg

[Pat Conlon]

David, you've got the extended Conlon family pulling for you. The candle is lit amigo. Let us know what you need.  Pat

Thanks Dan!
Got 40+ staples out of my neck last Thursday.  Still quite a bit of pain in the nerves surrounding the incision area, but fortunately the incision itself is still totally numb (but the doc says the feeling will return in a few weeks).

Unfortunately, the easy part may be behind me.  They took 17 lymph nodes out of my neck(!!).  I had no idea there were that many.  Only one (the LARGE 5cm one) had any cancer cells in it. Maybe they should have left a few to continue the fight (if necessary, but then I'm not a Dr.).

Anyway, I begin radiation and chemo next week (for 6 weeks) and the side effects of that treatment make the surgery seem like a mosquito bite.  Not looking forward to it at all.

But the good news is there is still no primary tumor, so the rad and chemo should eliminate any future occurrence

DavidR.

Oh yeah, the really bad news:  I had to cancel my plane ticket to Atlanta for the rally.  Cost me $150 to cancel a $169 ticket (thank you American).  :-(
Should have gone and just hung out, but too many appointments.

[ozzstar]

[/quote]

Nope, nice try, the bowls are vented by the large T fittings.  Those 4 small hoses are actually air intakes for the choke circuit.  I think the maintenance archives were pulled over from Yahoo.  Look there for detailed descriptions of the carbs operation, the metering circuits and tuning tips.

DavidR.
[/quote]

Hi David,

It would seem to me that if the intakes for the choke circuit isn't filtered then?  Since there isn't an air cleaner then these things have a potential to draw in dirty air into the carbs?  I don't understand why it would be designed like that...it seems like a bad idea.

Thanks

Glen

[SlowOldGuy]

It would seem to me that if the intakes for the choke circuit isn't filtered then?  Since there isn't an air cleaner then these things have a potential to draw in dirty air into the carbs?  I don't understand why it would be designed like that...it seems like a bad idea.

These tubes supply a very small amount of "bleed air" into the choke circuit as the fuel is rising up from the float bowl.  The main source of air for combustion still comes from the air filter.  The bleed air is similar to the air pilot jet, it leans the fuel as it is headed for the choke outlet port.  Since the choke is not used for an extended amount of time, filtered air is not a big risk.  Of course, filtering this air would be best, but it would complicate the plumbing to the airbox and make the carbs an even bigger pain to work on.

DavidR.

[ozzstar]

These tubes supply a very small amount of "bleed air" into the choke circuit as the fuel is rising up from the float bowl.  The main source of air for combustion still comes from the air filter.  The bleed air is similar to the air pilot jet, it leans the fuel as it is headed for the choke outlet port.  Since the choke is not used for an extended amount of time, filtered air is not a big risk.  Of course, filtering this air would be best, but it would complicate the plumbing to the airbox and make the carbs an even bigger pain to work on.

DavidR.

You certainly are the master of these carbs. Great explanation.  Hope you got my email about the O-Ring/screw kit I would like to purchase from you.

Thanks again

Glen