Throttle shaft seals

Where can I find them?

Thanks again guys,

Rich.

 

Calling Chacal - oh Chacal, are you out there? :wink:

Sorry for the smart-ass reply -- if you do a search of the forums you'll find topics on these seals already, and likely a link to Chacal's list of parts he has available.

 

Oh, Len.... aw, nevermind. Here's his parts listings for the throttle shaft seals and associated hardware. PM Chacal to place an order.

First, Hitachi:

------------------

Throttle Shaft Seals:


aaa) Aftermarket Hitachi HSC32/33 series carb Throttle Shaft V-Seal (sometimes called an "O-Ring", but it's not!)...these are the seals on the outside of the carb body that the throttle shaft passes through. Uses 2 per carb, BUT......without taking the carbs apart from the rack, the only ones you can replace are the outer seals on the #1 and the #4 carbs. Unlike the QR-series "o-rings" that many people recommend using---AND WHICH DO NOT FIT PROPERLY---these "V-Seals" do have the correct O.D., I.D., and thickness to fit both the throttle shaft and the carb shaft seal bore recess correctly. These V-seals are a superior sealing solution versus any other product out there!


HCP38B Aftermarket Hitachi throttle shaft V-seal, single:
$ 3.75

HCP38BSET2 Aftermarket Hitachi throttle shaft V-seal, pair:
$ 7.00

HCP38BSET8 Aftermarket Hitachi throttle shaft V-seal, set of 8:
$ 25.00


COMMENTARY: These seals are a VERY common source of vacuum leaks into the carbs, making tuning (synch, colortune, etc.) somewhere between very difficult and next-to-impossible. And here's the dirty little secret that no one really talks about:

If you read through these boards often and enough---or any other websites or lists devoted to these XJ bikes----you'll find a common theme in regards to these bikes, and it goes something like this:

"My bike doesn't run right."

And 9 times out of 10, it's due to a carb problem. And to make matters worse, these bikes don't just use one carb, they use four, which means that the synchronization of the four carbs to each other is critical in order for them to perform properly.

And 95% of the problems with the carbs is this: they are dirty (more like filthy!) inside due to age, and these seals are worn out. But to replace these seals (and also to properly get the insides of the carbs absolutely, positively, ZESTFULLY! clean), you're gonna have to pull the carb rack apart. Although that task is not mechanically difficult....nor does it take any special tools to do it.....the re-assembly process will MERCILESSLY PUNISH the careless or impatient mechanic or hobbyist. A tremendous attention to detail and organization is needed before you begin to take these carbs apart, so that you will have all the proper notes, drawings, sketches, etc. to put humpty-dumpty back together again, properly.

Since most people lack those skills or discipline, you will find most of the experienced experts on the various boards and forums telling you to NOT take the carbs apart, and to forego the proper cleaning and parts replacement steps needed.

I'm not trying to tell you to do, or not to do the task properly yourself; all I can tell you is what my own personal experience is. If you have the proper tools, time, and organizational skills and the PATIENCE to do the job right, breaking a rack apart and doing the job properly isn't that difficult. If you don't, it's a nightmare.

And the other dirty little secret is this: before you can synch and tune your carbs properly, you MUST check and adjust your valve clearances (replace worn valve shims), or all the synching and colortuning in the world isn't going to give you optimal results.

Sorry to be the bearer of such bad news, but as always, the truth will set you free (or at least solve most of your tuning and performance issues!).

Luckily, all of the parts and special tools needed to perform a proper tune up ARE available. I guess we should appreciate the little things in life more than we usually do........


a4) Aftermarket Hitachi HSC32/33 series carb Throttle Shaft O-Ring...these are the ones on the outside of the carb body that the throttle shaft passes through. Uses 2 per carb, BUT......without taking the carbs apart from the rack, the only ones you can replace are the outer seals on the #1 and the #4 carbs. Although originally Hitachi carbs used a licorice-like "valve packing material" to seal the shaft to the carb body, such material is not generally available anymore and dries out and thus leaks rather quickly. These seals are a true o-ring design, and although they have the correct fit against the throttle shaft on their inside diameter, their O.D. and thickness do not allow for as good a fit as the HCP38B V-seals listed above. But if you're doing an ultra-low-budget carb resto (quick question: WHY????), then these will work. These o-ring seals should be glued into the shaft bore with some gasket adhesive.

HCP904 Aftermarket Hitachi throttle shaft o-ring, single:
$ 1.75

HCP904SET2 Aftermarket Hitachi throttle shaft o-rings, pair:
$ 3.00

HCP904SET8 Aftermarket Hitachi throttle shaft o-rings, set of 8:
$ 5.00


bbb) Aftermarket Hitachi HSC32/33 series carb Throttle Shaft Seal PLASTIC SHIM WASHER...these washers go directly "outside" of the HCP904 o-rings or the HCP38B v-seals listed above. Same notes as listed above about the seals (regarding the ease of replacement) also applies to these shims. NOTE: these shims do NOT "wear out" like the seals do; you only need to replace them if your shim washers are broken or missing. ALSO: although these replacement shims have the correct O.D. and I.D. as the originals, they are only 1/2 the thickness of the originals, and thus you will have to use two (2) of these shim washers to replace one (1) original shim washer.

HCP39C Aftermarket Hitachi throttle shaft seal Shim Washer, single:
$ 2.00

HCP39CSET2 Aftermarket Hitachi throttle shaft seal Shim Washer, pair:
$ 3.75

HCP39CSET4 Aftermarket Hitachi throttle shaft seal Shim Washer, four shims:
$ 7.25

HCP39CSET16 Aftermarket Hitachi throttle shaft seal Shim Washer, sixteen shims:
$ 20.00


ts5) Hitachi HSC-32 and -33 series carb Throttle Shaft Retainer E-CLIP...these shaft retainer clips go directly "outside" of the plastic shim washers listed above on the #1 and #4 carbs only. Used on all XJ650 except Turbo, all XJ700 non-X, and all XJ750 models.


HCP6836 OEM throttle shaft end retaining E-Clip, bright plated spring steel, each:
$ 3.50

HCP6836SET2 aftermarket throttle shaft end retaining E-Clip, set of 2:
$ 6.75


HCP905 aftermarket throttle shaft end retaining E-Clip, black-phosphate coated spring steel as original, each:
$ 1.00

HCP905SET2 aftermarket throttle shaft end retaining E-Clip, set of 2:
$ 1.50


HCP2909 aftermarket throttle shaft end retaining E-Clip, type 420 stainless spring steel, each:
$ 1.75

HCP2909SET2 aftermarket throttle shaft end retaining E-Clip, set of 2:
$ 3.00

Mikuni:

Throttle Shaft Seals:


aaa) Aftermarket Mikuni BS-28, -30, -33, -34, and -35 series carb Throttle Shaft V-Seal (sometimes called an "O-Ring", but it's not!)...these are the seals on the outside of the carb body that the throttle shaft passes through. Uses 2 per carb, BUT......without taking the carbs apart from the rack, the only ones you can replace are the outer seals on the #1 and the #4 carbs. Unlike the QR-series "o-rings" that many people recommend using---AND WHICH DO NOT FIT PROPERLY---these "V-Seals" do have the correct O.D., I.D., and thickness to fit both the throttle shaft and the carb shaft seal bore recess correctly. Used on all XJ550, XJ650 Turbo, XJ700-X, XJ750-X, XJ900RK, and XJ1100 models.

HCP6838B OEM Mikuni throttle shaft V-seal, single:
$ 5.00

HCP6838BSET2 OEM Mikuni throttle shaft V-seal, pair:
$ 9.00

HCP6838BSET8 OEM Mikuni throttle shaft V-seal, set of 8:
$ 32.00


HCP38B Aftermarket Mikuni throttle shaft V-seal, single:
$ 3.75

HCP38BSET2 Aftermarket Mikuni throttle shaft V-seal, pair:
$ 7.00

HCP38BSET8 Aftermarket Mikuni throttle shaft V-seal, set of 8:
$ 25.00


COMMENTARY: These seals are a VERY common source of vacuum leaks into the carbs, making tuning (synch, colortune, etc.) somewhere between very difficult and next-to-impossible. And here's the dirty little secret that no one really talks about:

If you read through these boards often and enough---or any other websites or lists devoted to these XJ bikes----you'll find a common theme in regards to these bikes, and it goes something like this:

"My bike doesn't run right."

And 9 times out of 10, it's due to a carb problem. And to make matters worse, these bikes don't just use one carb, they use four, which means that the synchronization of the four carbs to each other is critical in order for them to perform properly.

And 95% of the problems with the carbs is this: they are dirty (more like filthy!) inside due to age, and these seals are worn out. But to replace these seals (and also to properly get the insides of the carbs absolutely, positively, ZESTFULLY! clean), you're gonna have to pull the carb rack apart. Although that task is not mechanically difficult....nor does it take any special tools to do it.....the re-assembly process will MERCILESSLY PUNISH the careless or impatient mechanic or hobbyist. A tremendous attention to detail and organization is needed before you begin to take these carbs apart, so that you will have all the proper notes, drawings, sketches, etc. to put humpty-dumpty back together again, properly.

Since most people lack those skills or discipline, you will find most of the experienced experts on the various boards and forums telling you to NOT take the carbs apart, and to forego the proper cleaning and parts replacement steps needed.

I'm not trying to tell you to do, or not to do the task properly yourself; all I can tell you is what my own personal experience is. If you have the proper tools, time, and organizational skills and the PATIENCE to do the job right, breaking a rack apart and doing the job properly isn't that difficult. If you don't, it's a nightmare.

And the other dirty little secret is this: before you can synch and tune your carbs properly, you MUST check and adjust your valve clearances (replace worn valve shims), or all the synching and colortuning in the world isn't going to give you optimal results.

Sorry to be the bearer of such bad news, but as always, the truth will set you free (or at least solve most of your tuning and performance issues!).

Luckily, all of the parts and special tools needed to perform a proper tune up ARE available. I guess we should appreciate the little things in life more than we usually do........



bbb) Aftermarket Mikuni BS-28, -30, -33, -34, and -35 series carb Throttle Shaft Seal PLASTIC SHIM WASHER...these washers go directly "outside" of the throttle shaft seals listed above. Same notes as listed above about the seals (regarding the ease of replacement) also applies to these shims. NOTE: these shims do NOT "wear out" like the seals do; you only need to replace them if your shim washers are broken or missing. Used on all XJ550, XJ650 Turbo, XJ700-X, XJ750-X, XJ900RK, and XJ1100 models.


HCP39C Aftermarket Mikuni throttle shaft seal Shim Washer, single:
$ 2.00

HCP39CSET2 Aftermarket Mikuni throttle shaft seal Shim Washer, pair:
$ 3.75

HCP39CSET4 Aftermarket Mikuni throttle shaft seal Shim Washer, four shims:
$ 7.25

HCP39CSET16 Aftermarket Mikuni throttle shaft seal Shim Washer, sixteen shims:
$ 20.00



ts5) Aftermarket Mikuni throttle Butterfly Valve Mounting Screw. Each round butterfly "valve" is held to the steel throttle shaft via two tiny phillips head screws. The throttle shaft has self-locking threads which makes the removal of these screws an absolute chore and usually results in a buggered phillips head slot. These replacement screws come in a variety of materials and drive styles. Use 2 per carb, 8 per entire carb rack. Used on all XJ550, XJ650 Turbo, XJ700-X, XJ750-X, XJ900RK, and XJ1100 models.

NOTE: these screws are an absolute BEAST to remove, and it is very easy to destroy the heads while trying to remove them. You may want to review the information in this forum thread before attempting removal:

www.xjbikes.com/Forums...html#66348


For all of the above reasons, our recommendation is to use the allen-head (hex drive) style screws to make future removal easier. ALSO, since it is not really feasible to peen or stake the screws once installed (as Yamaha originally did---they must have had a special fixture to perform this task), it is strongly recommended that you use some type of semi-permanent thread-locking fluid (such as our HCP1266 or HCP1267 thread locker fluids) when installing these screws.....as the last thing you want to have happen is having these screws back out during engine operation.....as that would be a sad, sad day for you and your engine!


HCP5899 aftermarket Mikuni butterfly valve retaining Screw, oval-head 18-8 stainless steel screw with a phillips-drive, each:
$ 1.00

HCP5899SET2 aftermarket Mikuni butterfly valve retaining Screw, oval-head 18-8 stainless steel screw with a phillips-drive, set of 2:
$ 1.75

HCP5899SET8 aftermarket Mikuni butterfly valve retaining Screw, oval-head 18-8 stainless steel screw with a phillips-drive, set of 8:
$ 5.00



HCP7120 aftermarket Mikuni butterfly valve retaining Screw, flat-head 18-8 stainless steel socket head cap screw with a 2mm hex-drive, each:
$ 1.00

HCP7120SET2 aftermarket Mikuni butterfly valve retaining Screw, flat-head 18-8 stainless steel socket head cap screw with a 2mm hex-drive, set of 2:
$ 1.95

HCP7120SET8 aftermarket Mikuni butterfly valve retaining Screw, flat-head 18-8 stainless steel socket head cap screw with a 2mm hex-drive, set of 8:
$ 5.50




ts5) Mikuni BS-28, -30, -33, -34, and -35 series carb Throttle Shaft Retainer E-Clip...these shaft retainer clips go directly "outside" of the plastic shim washers listed above on the #1 and #4 carbs only. Used on all XJ550, XJ650 Turbo, XJ700-X, XJ750-X, XJ900RK, and XJ1100 models.


HCP6836 OEM throttle shaft end retaining E-Clip, bright plated spring steel, each:
$ 3.50

HCP6836SET2 aftermarket throttle shaft end retaining E-Clip, set of 2:
$ 6.75


HCP905 aftermarket throttle shaft end retaining E-Clip, black-phosphate coated spring steel as original, each:
$ 1.00

HCP905SET2 aftermarket throttle shaft end retaining E-Clip, set of 2:
$ 1.50


HCP2909 aftermarket throttle shaft end retaining E-Clip, type 420 stainless spring steel, each:
$ 1.75

HCP2909SET2 aftermarket throttle shaft end retaining E-Clip, set of 2:
$ 3.00

 

How do I know what carbs I have and how do I go about ordering the right throttle shaft seals any help would be greatly aprieciated also who to order them from and whom to get into contact with its on a 1981 yamaha seca 750

 

If you contact Len aka Chacal he sells all the parts for the XJ series and has the seals you need contact him on info@xj4ever.com.

 

If the stock carbs are still fitted you have Hitachi HSC32 carbs.
as mentioned, contact @chacal
info@xj4ever.com