Is breaking/reassembling carb racks REALLY as easy as shown?

http://www.xj4ever.com/hitachi%20thrott ... 0seals.pdf

Other than extra time to clean, take pictures and reassemble the "rack" components is it really that easy to break and reassemble the RACK?

If so, it would be much easier/safer to soak the carb bodies and know I've replaced every rubber piece plus anti-seized or lock-tited every screw...

FYI: I have a total of 4 assembled carb racks, so having samples to look at while REASSEMBLING won't be an issue

 

Yes.

The "hard part" is getting all the carbs perfectly re-aligned in "both" planes; in other words, straight AND parallel.

 

exactly. AND.....getting them straight isn't that hard, either.

 

You can't replace every rubber piece unless the carbs are separated and taken down for the count........and thus you can't soak the bodies, because the throttle shaft seals will turn to mush......assuming you're "soaking" the carbs in carb cleaner versus, say, water......but of course, soaking them in water won't do much good.

 

EXACTLY! :wink:

 

I read the Mikuni section here: http://www.xj4ever.com/mikuni%20carb%20cleaning.pdf and wonder about removing the shaft seals. Is there anything tricky about doing these I need to know about? I want to completely rehab a set of BS34 Mikunis. Since the Hitachi are different, I can't rely on the writeup for them to know what to do.

 

The butterfly shaft screws in the Mikunis are split-staked on the backs (the little stub-ends) to keep them from unscrewing.

You need to file the butt-ends off the screws so they can be unscrewed without damaging the shaft itself.

I would NOT use a Dremel. One slip and you'll ruin a carb body.

 

Bob,

I've broken down dozens of racks and the only "difficult" time I've ever consistantly had was breaking the large screws that hold the rack together. They are typically locktite'ed and can be a bear to remove without stripping. I have a very good set of JIS screwdrivers that I use and they of course fit the Japanese Industrial Screws much better than a phillips and they amke a huge difference.

When I did my turbo's carbs, the white threadlock refused to give up the ghost and I ended up using channel locks to break them and remove them, then replaced 'em.

jeff

 

Etch Identification Numbers on the Throttle Plates
Dont use Marker of Sharpie --- Those Marks disappear.

Strip the Rack down to Bare Bodies in one work area.
Shift to a well lighted and comfortable work area to do the Shaft Seals.
Create a deadened work surface that will not allow parts to get lost.
A Pillowcase over a Towel.
Drape a Hanky over the work when installing Springs.

Chain-saw Sharpening File, Ignition Points File or Jewelers File to relieve peening of Screws securing Throttle Plates
> Tix Solder if Throttle Plate Securing Screws are reused.

> Jap Precision Screwdriver Set
http://www.centralhobbies.com/tools/jis.html

Ice Cube Trays X 4

 

Did you threadlock the new set of screws? Blue/Red/White?

 

Impact drivers work well for loosening rack screws. Do it on the floor on a piece of wood (so you don't knock the carbs off the table), with bowls and hats installed and shims to hold the carbs level when you strike. You'll get those rack screws off in no time. I even stripped out a head such that I couldn't get the impact tool to bite, rapped on the bit alone to make and impression, then used the impact tool to remove.

 

In my other thread I had good luck getting out the buggered drain screws on 2 racks. The other rack won't budge even with kroil and impact.

Btw I have 4 total racks (from 750s), 4 airbox boots, 4 more just ebayed, 4 exhaust side boots just arrived in thebmail, and the boots on my parts bike.

I think I have the technology and parts to rebuild the six million dollar man.... Errr carbs

 

That's the spirit Bob, keep a sense of humor and it makes it all go easier. A factory tuner used to say back in the 70's that if you ever want EVERYONE's advice at the track, holler out that you need jetting advice....well, carb rebuilding is kinda the same....lots of good advice here....keep it simple, clean, and make sure that each piece stays married to it's carb. Don't think I read it above but setting the carbs, engine opening flat on a glass table will assure alignment as you snug them to the rack and to answer someone elses question, blue is the threadlock I use for nearly all screws and nuts on a bike except things like crank end's, clutch nuts etc.

jeff

 

Impact Tool with a Bit fitting into a fabricated Slot is KEY.

Supporting the work such that the Force of the IMPACT is ALL applied to that Stuck Screw is vitally important.

The Handle of a Broken Baseball Bat can be "Sculpted" to FIT right into the Bowl.
Using a Orbital Sander or a Small STANLEY "SurForm Tool", ... --> Sculpture the Knob on the Baseball Bat Handle to FIT into the Fuel Bowl.

http://www.tylertool.com/stanley-21-295 ... 4AodSkkY0g

Remove just enough wood so that the Bowl fits-on the end of the Bat snug and tight.
Once you have the Jig to hold the Fuel Bowl, ... lock the Jig in the Vice so that you have a comfortable working position to apply IMPACT to the DRAIN SCREW.

You have the right set-up when the BOWL is firmly held from moving when the Impact is delivered to the Stuck Screw.

You want to achieve applying the Impact to the Screw and NOT having the BOWL move at all upon the application of Blow to the Impact Tool.

:::: CAUTION ::::

IF, ... the Bowl moves ... there is a tendency to *** Apply a stronger amount of Impact*** to compensate for the Force LOST to the Bowl not being firmly anchored.

••• Increasing the FORCE of the IMPACT Blow to the Impact Tool on a Fuel Bowl that absorbs the Impact Strike ... by NOT being firmly anchored ... will let the whole Fuel Bowl be subject to the force of the Impact ... increasing the possibility of the Fuel Bowl being misshaped and fracturing. •••

 

Good info here, ill deft be keeping it in mind!