I've searched high and low but no answers on this XJ carb problem:

Hi All, first post...1982 Yamaha XJ750J Maxim . Carb rebuild. So I go to remove the first main jet and it moves but real sticky...and actually keeps on spinning but no progress. I eventually identify that the emulsion tube is spinning with it and it just aint gonna come out. It's actually quite loose now (the emulsion tube and jet) so this jet will not be coming out. I moved to the other jets and immediately verified that the emulsion tube for each starts spinning immediately when I start loosening the main jet. Now I'm thinking the only solution will be to carefully, surgically grind off the main jet until I can release the tube and then see about drilling out the jet remnants and hopefully save the tube. Any thoughts on a better solution or similar experiences?

 

I suggest waiting to do anything that will be permanent until one there is a response from one of the folks here that regularly works on carbs. They don't typically need anything ground out.

 

Will do. I'm investigating parts ordering for now. Thanks!

 

Remove the slides if you have not done so already.

At this point I am going to sound like my grandfather, so bare with me.

Whittle you a stick.
Make it have a cone shape at one end so it can fit snugly into the top of the emulsion tube.
USe that to hold th emulsion tube as you unscrew the jet.
It is wise to apply penetrating oil (not WD-40) to the threads of the jet to help the threads free up.

You may have to run the jet in and out a bit to help clear debris from the threads before it will back out all the way.

 

Thanks, I'll give it a go and let you know. I have this strange feeling the tightness of these jets is a combination of being overtightened on a previous clean and potentially some threadlock applied. They are super snug but maybe your trick'll work. Thanks again.

 

How many people these days would have to Google 'whittle', I wonder?

 

Quite awhot, I would guess.

Got my carbs in the freezer now. Hoping the press fit of the tubes will tighten up that way and help hold them in place. Found some straw to chew on while I prep the wood.

 

A chopstick sometimes works to hold tube while you unscrew jet

 

Tried the carved stick and though it might have been viable if at least the jets had started to loosen up it appears that actually "breaking them loose" from those tubes just wasn't gonna happen so... out came the hand held grinder and off came the heads of the jets. It actually worked great. Once the head was gone the tube dropped out and with a bit of torch and some pliers the "friggin" jet remainder easily backed out. I'll order some fresh jets and all should be good. Now I can also become part of XJ lore: as in "I know a guy that rebuilt his carbs with a grinder". Try offering that advice to anybody.
So the next question is...is there a specific technique for the reinstall of these tubes once I get the jets? I foresee being unable to tighten them without the same spinning taking place?

 

In my (limited) experience, the fact that they are pulling each other together works just fine to keep them from spinning.

 

Did you find out why they were so tight and the emulsion tube turning on you ?

Was there gunk or threadlocker on them ?

Just make sure you don't use any on the re-assembly

 

Put the grinder in reverse.

Get your replacement jets and rebuild parts from XJ4EVER read this: http://www.xj4ever.com/inside your carbs.pdf and then do this: http://xjbikes.com/forums/threads/in-the-church-of-clean.14692/

Inquiring minds want to know:
Exactly how did you grind the heads off? No "oops" and marring of the carb throat?

 

K-moe is right but if you use the foam paint brushes....the ones with wooden handles and break the foam end off, the wood is the perfect softness for the job. I've been doing it this way for year and it works 90+% of the time. Take the wooden handle and using a ball peen or other light hammer, hammer the wooden dowel right over the shroud(use a handle-dowel that is larger that the shroud)...it will sink into the soft wood with deflecting and it's large surface area will actually help hold that end while you apply a tool the the jet to remove it. It helps if you heat the top(shroud side) with a torch at low heat while applying a lube such as Kroil to the jet threads. Capillary attraction will cause the lube to seek the source of the heat drawing it down onto the threads......patience and judicious use of force will prevail....does every time!

jeff

 

I found nothing really. No evidence of threadlocker. I am pretty boggled as to how all of my main Jets were doing this and yet it seems evident that this hasn't really happened to anyone out there before? I am going to mark it down as simply a case of the main Jets being installed way too tight and probably never coming out for a very long time.

 

I ground off the jet inside the main bowl so the carb throat really never was threatened by the grinder at all.

 

Unfortunately the grinder does not have a reverse setting so I will be stuck doing the job with a screwdriver. Unconventional but hopefully I can get the job done.

 

I actually had some dowel stock which I whittled to a shape that lined up pretty much as you described. Try as I might I could not keep the tube from spinning when I loosened the jet. I didn't apply heat or a lubricant on the jet or bowl body which may have been the solution.

 

I just jam a pencil in the tube when I've had to do this

 

Oh, I sure hope it isn't many people. I can't be that old, can I?

 

But not as many as would have to Google"awhot"

 

was there a copper washer under the jets?

 

"was there a copper washer under the jets?"

Probably not but I have seen some so entrusted with thick lacquer that they take a bit to free up!

If the dowel is large enough, the shroud should embed into it so it can't possibly spin.....

jeff

 

There was copper washers under all four main Jets. They were lacquered up a wee bit but are now destroyed from my grinding efforts. I really can't explain better how those Jets were so incredibly difficult to remove even with the dowel pressed firmly against the underside of the tube outlet. I am now ordering parts from XJ forever

 

Most likely a meat-fisted PO

 

Isn't it called "ham- fisted"

 

Ham-fisted....meat-headed---about the same thing, isn't it? Lol

 

I think on this website "bacon-fisted" would be appropriate.
Cause we like Baaaaacon

 

Bacon-fisted: when Matti runs out of room on his plate at the breakfast buffet.
Also see: sausage fingers.

 

They took my whittling knife at the airport.

 

Some nice security screener in Costa Rica has my Leatheman. Remember kids, always take you knife out of your daypack, and put it back into the checked luggage, before heading to the airport.

 

Been Franklin:
"Those who would give up essential liberty, to purchase a little temporary safety, deserve neither liberty nor safety."

 

Several years ago, my wife and I were an hour from heading to the airport for a trip. My adult daughter suggested my wife go through her bag to get rid of unnecessary weight - she usually has a kitchen sink, an anvil or two, etc. in her purse.

In the bottom of her purse she found...a box cutter!!!! Unbelievable, can you imagine how long that would have held us up for questioning by TSA?

 

Can you say "Cavity Search "

 

I must be one of those - meat/ bacon fist guys. I rebuilt my carbs last winter, and I remember making sure the jets were GOOD and TIGHT.
Now I might be in for a surprise when I return :--(