Teflon tape on needle valve seat

[chaunceyw]

Does it belong? It looks cruddy and I don't see it used in manual.

I cleaned my carbs and introduced a hesitation when opening throttle so now I'm trying to figure out why and came across this.

If the bike is idling and I crank the throttle it seems like it chokes a sec then revs up. If I go slow it's ok.

The screwdriver slot on one of the pilots looks chipped but the hole is fine.

Ideas on these two matters?

[FJ_Hooligan]

Should be o-rings on those needle seats and NO teflon tape. (o-rings available from Randy)

Check your fuel level / float height.  Too much fuel in the bowls will sometimes cause a stumble.

Can you clean up the slot in the jet with a small file? (new jets available from Randy)

[JoBrCo]

Definitely no jury rigged Teflon taped needle seat o-rings, new o-rings are in order.

The screwdriver slot doesn't have anything to do with metering, as both jets are submerged in fuel, on the other hand, the orifice being buggered up would definitely require a new jet.

It looks like at least one of your needle seat screens is pushed in, I'd probably carefully and gently push it back out without disturbing the mesh's pitch, not that it's a big deal, really.

FJ Forever!  

JoBrCo

[chaunceyw]

Yea I already pushed the screen back out.

I have a spare bank of carbs so I pulled the needle seats that had some good o-rings and stuck them in. Also replaced the pilot jet even though the general consensus is that it's fine.

The float heights all seem okay... so I have no idea what is causing my hesitation. I sprayed everything out again with carb cleaner and compressed air and put it back together. I will test in the morning and hopefully I'll have better luck.

I foolishly stored my jets in a styrofoam egg container.... yea.... you probably know where that's going. I had to soak them out again for a couple hours to get the melted styrofoam off!! Live and learn.. haha

[red]

I cleaned my carbs and introduced a hesitation when opening throttle so now I'm trying to figure out why and came across this.  If the bike is idling and I crank the throttle it seems like it chokes a sec then revs up. If I go slow it's ok.

chaunceyw,

Idle RPM should be 1100 or more; below that, you can get some hesitation, as described. 
These carbs do not have accelerator pumps, although some aftermarket carbs do. 
Those aftermarket carbs are expensive, though, so they are rarely used here.

Red

[chaunceyw]

The problem wasn't happening before I cleaned my carbs and certainly there was no backfiring.

At around 2k rpm there's a little power drop and right around there is where backfiring happens.

I popped off the unipods and it seems like the backfires are coming back through the carb where the filter connect. It seems to be consistently carb #3 but I saw #2 backfire a couple times.

I've got the carbs off and I'm going to re measure the floats again.

Frustrating.

[FJ_Hooligan]

What you're describing is typically a lean condition.  Did you remove the idle mixture screws and clean the entire idle circuit?

Are all the unused sync ports plugged?

Have you had the plugs out recently?  I've seen this happen from a cracked (dropped) plug.

[Charlie-brm]

I'm half smiling because I did a band aid similar to that with pure silicone tape, my first week of ownership. I'll save you the story of why and how except to say that you may find the tape has broken up and the bits are wandering around in the carbs, playing mayhem with your system in a random fashion. It's just a lead to consider. The cleaner chemical might have accelerated the teflon break down so it's acting up now.

The other FIY - I read (probably on FJowners.com) that some industrial suppliers have fuel suitable o-rings in sizes 0.1 mm larger than spec., which was suggested for a tighter fit on worn parts.
eg. I had no problem requesting 1.6 x 7.1 mm o-rings. They fit firmly with no issues.

[movenon]

I'm half smiling because I did a band aid similar to that with pure silicone tape, my first week of ownership. I'll save you the story of why and how except to say that you may find the tape has broken up and the bits are wandering around in the carbs, playing mayhem with your system in a random fashion. It's just a lead to consider. The cleaner chemical might have accelerated the teflon break down so it's acting up now.

The other FIY - I read (probably on FJowners.com) that some industrial suppliers have fuel suitable o-rings in sizes 0.1 mm larger than spec., which was suggested for a tighter fit on worn parts.
eg. I had no problem requesting 1.6 x 7.1 mm o-rings. They fit firmly with no issues.

I use a slightly larger 7.1mm ID by 1.6mm X-section Viton.  I got mine from Oringsandmore.com out of Richmond, Va but you have to buy a bag of them (25). They are inexpensive.

[JoBrCo]

This place has Viton and other materials, all the sizes that are required for the Mikuni 36's and you can buy as many as you want, no minimum.  Though I never actually purchased there before, they were in my cart, and it appeared as though I could, nothing came up concerning a minimum. I just decided to get them from Randy instead, because of the SS hardware.  The funny thing is, now I'm not going to use the SS hardware.  Oh well, that's the way the cookie crumbles.

FJ Forever!

JoBrCo