Air cut off valve jammed.

[*Touring Ted*]

Before I take my newly acquired TT600 to Mongolia I thought I'd strip and clean the carb.. I discovered a jammed Air Cut off valve.

It's not budging and I can't get it out. Someone has already had a go in the past as there are tool marks.

Any tricks ???

[g6snl]

Don't you just hate it when you find stuff like that!

Heat
Freeze
Boil
Soak in coke. Seriously! it has worked for me on things.
Pray ( this has never worked )

Drill out and replace?

[*Touring Ted*]

I was going to use heat but there is plastic washer behind it. Which may melt and block the vent hole.. Making my day even worse ha !!

It's soaking in WD40 now. Still jammed. Brass means it too sold to get hold off too. Daaaaaam.

[xtrock]

Do you have wisegrip? Maybe use dremel and cutting a few lines for better grip.

[mollydog]

Ted,
If it's corrosion holding it (doubtful?) the Go is a 50/50 mix (more or less) of Acetone and ATF (automatic trans fluid). Best penetrant rust dissolver ever. Beats them all.

If that does not work you may have to drill it or replace carb body.

If you can cut a BIG screwdriver slot in it (Dremel) try using an IMPACT Driver to break it loose. NOTE: you may break carb body doing this, so take care.

[*Touring Ted*]

I've had on good word from someone who works these carbs daily that they won't pull out. The core needs drilling out out, the outer tapping and then drawn out.

Not much margin for error there.. But if needs must.


The bike didn't pop on over-run. But I don't know if it's jammed on or off.

It can be tricky to start (A TT600 niggle), but runs well.

[jjrider]

I had one that was stuck , don't know if as bad but I believe I took an air hose to the port from the back side to pop it out . I have a rubber tip that can be pressed against the hole and seal it up the 150psi. I don't think mine was corroded in just some gummy old fuel.

[*Touring Ted*]

Originally Posted by jjrider

I had one that was stuck , don't know if as bad but I believe I took an air hose to the port from the back side to pop it out .

Tried that.. Not budging at all.

[jjrider]

Grease gun ? pump it from the same side as the air gun? They build up quite a bit of pressure , holding the tip tight would be the hard part.

Not much else but to drill and try tapping for a pullout.

The other option I see is that hole that the plunger is stuck in is cast all the way to the back side, just not drilled through. A person could drill from the end to get a 4mm punch in and once out, tap the hole for a pipe plug.

[*Touring Ted*]

Part of the problem is that I don't know exactly what is behind the plunger. I have bought a repair kit which is the post but that doesn't match the rubbish picture of it in the manual...

[Moto Phoenix]

I've no experience with these motors, but you could try getting the assembly well warmed up with a hot air gun, then shocking it with Wurth Rost Off Ice, or similar.
It has worked for me in the past.

[jjrider]

Just have to ask



It's just drilled the diameter of the plunger outer piece then has a flat bottom for the spring. The wall on the back side is maybe 1 to 1.5mm thick.

Once the whole part is out on mine I see air or grease from that hole in the back won't have as much push as it could because of where the hole is , though all that is holding is 1mm of that endcap if the plunger is moving , if the plunger is also stuck then there is quite a bit more holding. It took quite a bit of force to get mine out here , and my plunger was loose and working, just that cap was tight as heck.

[*Touring Ted*]

Originally Posted by jjrider

Just have to ask



It's just drilled the diameter of the plunger outer piece then has a flat bottom for the spring. The wall on the back side is maybe 1 to 1.5mm thick.

Once the whole part is out on mine I see air or grease from that hole in the back won't have as much push as it could because of where the hole is , though all that is holding is 1mm of that endcap if the plunger is moving , if the plunger is also stuck then there is quite a bit more holding. It took quite a bit of force to get mine out here , and my plunger was loose and working, just that cap was tight as heck.

Great..... Thanks a lot


Just to confirm. Did you drill the plunger out of the middle first ???

Or did you just drill out the top collar ???

When I blow air into mine, it just comes out of the centre.


Thanks, Ted

[*Touring Ted*]

I think I will drill the centre plunger out until just below the collar. Then I will increase drill bit size until it is just a little smaller than the diameter of the collar. It should come out then.

Then I will have to see what the plunger is like underneath.

These carbs are VERY rare. I don't want to screw it up !!

[jjrider]

I didn't have to drill anything , this one came out just pulling out on the plunger. If you drilled from the back with a .125 drill you could just push the setup out with a punch . The hole would need to be plugged back up though.

My internet access is messed up and almost impossible to upload the picture for the plunger (why I couldn't even respond earlier)