TOPIC:

Been several years since my carbs were off my bike and with it running poorly lately I decided it was time to pull them, bathe them and tune them up.

To my horror I found 2 of the choke tubes (not sure what they are actually called) were broken and had been secured with epoxy. Been so long I cannot remember who did it but I have an idea. '

These tubes are no doubt pressed it. Can the be removed? If so how and can replacements be found.

My mechanic says he will come up with a fix if not.

In a perfect world I would have a spare rack of VM28SS kicking around. Sad thing is I did have a spare rack 10 years ago.

What would Jesus do? Or any Mikuni expert for that matter. Suggestions anyone?

Its carbs 2 & 4 in the picture (also carbs 2 and 4 on the bike when flipped over and mounted)... They are missing from the top left area of carbs (you can see the holes where they are meant to be)





Here`s the fiche... what part is this tube?

W

If I did not have any other choice then to dump a ton of money in a new set of used carbs, I'd just clean the aluminum alloy casting up, scrape the crap out, and after making sure the brass tube is REALLY clear, carefully epoxy the brass tubes back in but with a greasy +.009" dia wire stuck in it to keep the tube and orifice open and use a good epoxy gusset around the brass to aluminum alloy casting.
Then after a few hours, when they epoxy has really set up hard, spin and or run that fine .009" dia wire through the tiny hole in the brass, and then.... I'd just forget about it put them back on and ride the hell out of the bike.

those come out real easy with some heat. I don't think you have a problem there. A lot of times I take them out when I'm doing a carb cleaning. You just need to find some off a donor set.

You have the tubes. They have jet holes in the bottom. Id Mic them, buy a drill that size and reset the ones you have. Who cares if they're 1/4 " short. It's the choke.
Steve

One of my carbs on my '78 Z1-R has the choke tube broken off at exactly the same point and I've been working on whether to epoxy/JB weld the original bit back on or drill out the remaining bit and fit a new tube (I have the tube stock but will have to drill the cross holes and blank off the end then drill the .009"hole in the bottom) I'll be very interested to see the best solution here! Please share your thoughts and experiences with this repair so we can all learn.

Maybe try asking the question at WGCarbs.com in the Vintage Forum.
wiredgeorge doesn't visit KZRider much any more & his fix may be a trade secret.
I looked in the Archive here on KZR but didn't find anything.

FYI guys epoxy will not last if bathed in gasoline, it will break down.

I've used it to seal a float. If not totally encapsulated, it will lose it's stick and leak.
Steve

baldy110 wrote: FYI guys epoxy will not last if bathed in gasoline, it will break down.

I don't know if that is 100% true but I'm pretty sure marine grade epoxy is fuel proof and there are probably many other epoxies from manufacturers that are fuel proof.
I'd just call a NAPA dealer and ask about the good stuff.

******
I just looked around and finding a 100% fuel/alcohol proof epoxy is harder then I thought.
This looks promising but still not claiming 100% fuel proof.
Master Bond EP-41S-1 epoxy resin

Those emulsion tubes have their own shaft they fit in. If you'll look at the others, you'll see a hole at the top. I don't think you'll have a problem with shorter ones but make sure you have the right size vent hole there. My 33's have a jet at the bottom of the shaft leading into the bowl. I cleared one of them and noticed a difference. Why? I don't know but I will make sure all of are clear next time I have my carbs off. .
Steve

swest wrote: Those emulsion tubes have their own shaft they fit in. If you'll look at the others, you'll see a hole at the top. I don't think you'll have a problem with shorter ones but make sure you have the right size vent hole there. My 33's have a jet at the bottom of the shaft leading into the bowl. I cleared one of them and noticed a difference. Why? I don't know but I will make sure all of are clear next time I have my carbs off. .
Steve

Steve, I think he is only talking about the 1/8" dia, pick up tube for the choke enrichment system, not the emulsion tube on top of the main jet.
Well, do they call that pickup tube an emulsion tube also??

I had to fix the overflow stem on a set of CV34s. pretty similar problem. this might help you out. BTW i used Seal-All on it. Its supposedly wont deteriorate from gas.
kzrider.com/forum/3-carburetor/596928-re...w-stem-in-float-bowl