Wet-setting - Kindergarten questions

Hey y'all,

Well the carbs are back together, after a *complete and thorough* cleaning per the many tutorials (rack not broken apart). Next step - wet-setting.

Now, let's pretend I'm a total idiot. (I know it's possible, as several of my ex-girlfriends were able to 'pretend' this for months or years at a time.)

SO FAR:

I've got my carbs clamped to a board, which is in turn clamped into my bench vice. This actually works quite nicely, as it affords me good access to the bowls, floats etc.

I've got my fuel tank on the workbench (petcock freshly rebuilt, tank rinsed out, a gallon of non-ethanol fuel in the tank.) It's sitting on blocks, putting the petcock about 12" above the level of the carbs. It doesn't have a working upper cap at the moment; new one is in the mail.

I was an idiot, and tried to save a few bucks ordering carb kits online rather than through a trusted vendor. (I know, I know.) The ends of the valve seats are turned to a different diameter, and while they screw in fine, they don't fit the micro-filters. So I thought I would try the old seats with the new needles.

Now, when I first hooked up the tank and set it to Prime, gas just POURED out through several (all?) of the carbs. Pulled the bowls, and realized I had one float on upside-down. (Whoops.) Fixed that, and gently tweaked the float tabs a bit. On my fourth or fifth try, I'm down to slow drips out of maybe two carbs.

I haven't really got to the point of checking my levels yet. I did try once or twice, but when I cracked the drain screw, fuel would flow up the measuring tube to above the carb/bowl joint.

My first impression is that the new needles, although almost identical to the old ones, are perhaps 1/2mm shorter than the old ones, which is maybe what's contributing to the overflowing. Also, the PO hadn't done a great job, so I'm not going to assume everything was 100% before the rebuild.

QUESTIONS:

1) Does it matter if my tank doesn't have a cap, for test purposes? No, right?

2) The whole process is done with the petcock set to prime, and fuel in the tank? If I raise the tank itself too high, am I not creating pressure which may overcome the needle's ability to stop the flow into the bowl?

3) Process going fwd? Keep trying using new needles and old seats? (Polish up old seats with q-tip in drill and some Brasso?) Use new seats w/out screens, and install inline filter? I'd *really* rather not waiting a week (and a drive to the border) for new kits.

Yes, I have reviewed the PDF on wet-setting, but my questions are either too basic or too situation-specific to be covered there. Thanks in advance!

 

1) NO it does not matter (you are correct in your conclusion).

2) YES (petcock set on prime) and then NO (within reason.....don't set the tank on the moon, for example). 8O

3) NO (to using new needles and old seats, or vice-versa). The needles and seats are matched units, there are at least 4 (that we know of) primary manufacturing sources for the Hitachi HSC** series of carb float valve components, two of them won't work: one provides a completely incorrect kit for the Hitachi's, the other is of questionable quality. The other two are just fine, but use different size/style screens from the original pieces (the original seats used a "domed", split-ring style screen). Polishing the old seats with (anything) won't help, as the problem lies within the mis-matched (or wholly incorrect) parts themselves, rather than any flaw within the machining of said parts (i.e. they are "machined" correctly, they are just the wrong (albeit VERY similar) parts for these applications).

You can use the seats w/o their mini-screens, but why? The more filtration the better! Carbs do not like junk and ferrous grit running thru their mostly soft brass (and rubber) "working parts".

P.S. the "wrong" seat/needle kits are all over eBay and many of the "name" on-line sellers.....perhaps they just don't know, but since the problem has been on-going for at least 5 years, perhaps they simply don't care, either. These old Yamaha's, which are the primary users of the Hitachi carbs (of this series), are just not a very big market (compared to Mikuni's, for example).

BTW, USA version (and perhaps Canada, too) formula of Brasso is absolute junk. Get it from the UK or Euroland, you can still get "real" Brasso over there, it's the bee's knees.

 

1) Nope. Petcock on Pri is gravity fed which will flow regardless.

2) Also nope. Once the fuel reaches the set float height, the float will rise, and the valve will (should) close, preventing more fuel from entering. Your needles are wrong, but I suspect that your float levels are too high anyway.

3) You'd not wanna wait a week, which is understandable. But getting the job done right the first (or I guess second time in this case), matters. Going forward is a bench sync, then mounting them, then a vacuum sync, colortune, vacuum sync, and final colortune. Ideally, anyway.

 

Thanks guys, I appreciate the timely input. Len, an extra thanks; I should have known that the extra $ would be well-spent when going to a vendor who knows his stuff. I'll be coming to you for my brake parts, for sure.

http://www.outlawracingproducts.com/bacareki.html

That's the same kit I bought (see second photo) - outer bag is branded "Outlaw Racing Products", bar code says "Made in Taiwan". I complained to the vendor, who refunded me half my purchase price.

Len, do you know which manufacturer this is, and whether it's usable? I'll try swapping in the new seats tomorrow as suggested, and see how that goes.

 

And PilotSmack, thanks for that list... I already have a Colourtune (used to have an old MG, they're still used in the LBC world) so that's one less thing to buy! Planning on building myself a bottle sych tool along these lines: https://www.youtube.com/watch?v=Y_WDF6glD5k

 

I just used a couple mason jars, some hot glue, and leftover fork oil. Ya do what ya gotta haha

 

I just went thru the rebuild, wet set, synch, tune "Hitachi Loop" twice in the last two weeks on two different bikes and regarding your initial questions; in my experience, using aftermarket valves with the non-screened seats is fine as long as: 1) they are correct to your carbs, 2) you use an in line fuel filter (IMPORTANT: use the fuel filter while wet setting too!).

If you've got a YICS bike, you'll of course need a YICS tool to synch. I have had very good luck withtheseinexpensive but effective tools.

 

Sorry, it's really impossible to tell from the picture..........all of the float valves look the same, the needle that is shorter than the original needles is a giveaway clue, though.

 

I couldn't agree more; going anywhere else for XJ parts is like playing Russian Roulette with your bike, and maybe your life. :wink:

 

Well, that went well!! Swapped in the new seats and everything went smoothly (if slowly).

So glad I had purchased new hex-socket head screws for the bowls... I must have had them on & off twenty times. Petcock to Run, drain everything, bowls off, adjust tangs, bowls on, petcock to Prime, let everything fill, check levels with clear hose. And repeat. And repeat. And repeat. And repeat.

All four are now filling to 1mm below the carb-body-to-bowl line, measured at the halfway point on either #1 or #4, and sealing nicely. Looking forward to putting them back on the bike tomorrow, popping in the new AGM battery, and seeing if she'll run. Then, as above, vacuum synch and colortune, and I can move on to brakes and signals.