Fuel inlet 'T-pipes'...

I've tinkered with and adjusted many a set of Mikunis over the years, but have never had an issue with or had to replace one or both of the 2 fuel inlet 'T-pipes' (pictured below) or had to disassemble the bank of 4 carbs individually. Scenario:---'fairly new to me' set of 26mm Mikunis of the '76-'77 series bought from an ebay source who I have trusted for several years. I don't know their entire history but they are great in appearance inside and out and supposedly "bolt-on-ready-to-use". My current purpose for this particular carb set is for test-running engines on a run stand (or in my shop a bare rolling chassis with necessary electricals). Even so, I replaced pilots, mains, float needle/seats, air screw/springs and gaskets and reset all adjustments (slide heights, air screws and such) to default settings. Yayaya that's all fine and good. Next step was to check float fuel levels via the clear tube test. Mounted carbs on my spare cylinder head (for bench top adjustments), turned on fuel supply from auxilliary tank and fuel running out of both fuel inlet T-pipes where they swivel. It seems as if they swivel a bit more freely than they should. Anyone else had this problem or had to replace these? Replacement obviously requires removal of #1 and #4 carbs to replace the fuel inlet T-pipes which are available and in-stock from Z1E ( www.z1enterprises.com/product/16046-002 ). Seals required? How do they seal? Over the last 40+ years I have read countless articles and seen many a video relating to Mikuni carbs, but I have yet to see anything pertaining to this problem, and I don't personally know of anyone that's had to replace these. Anyone's personal experiences with this similar issue would be greatly appreciated.
.........................................Mike

Vroom-vroom!!!

common problem the rubber gets old and shrinks and leaks.
the aftermarket fuel t's use an o-ring to seal.
i have a set of the billet ones on my carbs on my 80 z1r.
on one set of my carbs before the aftermarket caught up .i cut the rubber back with a razor and installed o-rings on the modified t's and it worked until the o-rings got old and cracked.

leon

One thing you could try before buying replacements is to let them stay wet for a day or two and see if they still leak. The "T" on my KZ650 carbs leaked the same way after I had the bike in my basement over a winter. I had removed the tank and drained the carbs as a precaution against fire. At that point there was no fuel left in the "T" or hoses. In the spring when I put the tank on and turned on the petcock the "T" leaked pretty badly. I shut off the petcock and spent a couple days looking for a new "T" with no luck. Out of frustration I turned the petcock on again to see how bad the leak was and to my surprise it no longer leaked at all. It seems unlikely, but I can only assume that the fuel caused the seal to swell back up and make the joint tight. That was 9 years ago and it hasn't leaked a drop since. Ed

Thanks for the tips and input. I will give the fuel time to possibly 'refresh the seals' before I order replacements. I must've missed this one when searching the listings... ( www.z1enterprises.com/product/ZSM46-002 )...as it shows the o-ring seals included also. (must be old age creeping up on me LOL)! ..............................Mike

Vroom-vroom!!!

Give them a chance and keep them wet, they should come back.

I soaked the original T's from a nasty looking set of 77- 26VM in gas while I was rebuilding the carbs.

I know they haven't been used for 35 years and they are working as they should.

Good old wintergreen oil treatment! Rejuvenates rubber.
Plus I always used teflon tape for years. That fixed it for me. Wrap 3 or 4 times with the tape
I never bought new ones.

Got a set of the aluminum T's for the VM 26's on my 78 GS1000 .Work great and I must admit I like the bling they add.Pretty sure the old ones may have sealed after a bit but I wanted to be sure.Want a set for the BS32's on my 82 GPz750 but finding those is a bit harder :dry:

Here you go! Here is the machinist that started out making fuel level tubes. Send him a request for what you need.
Excellent craftsmanship! He might already have them. Check his items.
I have purchased several of his items!
He's out in Montana.
www.ebay.com/sch/gunsbluemoon/m.html?ite...rksid=p2047675.l2562

Thanks again for your insights. Good chance I'll have them apart next day or so for a closer looksee at the T's. Never disassembled a bank b4 but this being a test set, it's time I see 1st-hand how it's done per my handy trusty manual's easy to follow instructions LOL. The way I see it, U can't know how stuff works with out taking it apart??? hehe. But then getting something apart is easy, it's the proper reassembly and adjustments that's the kep part. I have another backup set of older VM 28 SS's from the Z1 900 era that need a good thorough cleaning and new gaskets. 3 motors to test-fire to see how they sound and react on my test stand and determine which one I will use for my 1327 build later this Summer. My newly acquired set of new RS 38's ( for the 1327) aren't quite practical for testing stock motors lmao. .........................................Mike

Vroom-vroom!

Heck, 26mm are simple, 28mm's are a pain.
If you do get in to more like taking the needles out of the slides.
Make sure you got a new perfect fitting #2 phillips or JIS bit. Those screws give ya trouble sometimes

z1kzonly wrote: Here you go! Here is the machinist that started out making fuel level tubes. Send him a request for what you need.
Excellent craftsmanship! He might already have them. Check his items.
I have purchased several of his items!
He's out in Montana.
www.ebay.com/sch/gunsbluemoon/m.html?ite...rksid=p2047675.l2562

Thanks for that link. ................................Mike

Vroom-vroom!!!

z1kzonly wrote: Heck, 26mm are simple, 28mm's are a pain.
If you do get in to more like taking the needles out of the slides.
Make sure you got a new perfect fitting #2 phillips or JIS bit. Those screws give ya trouble sometimes

Ya true that is...good point, been there done that. I found years ago that grinding just a fraction off the tip of a standard phillips screwdriver gave it a much better fit and had much fewer problems with Jap-made screws. .........................Mike

Vroom-vroom!