I think I need new butterfly shaft seals

When I spray carb cleaner on the exposed ends of the butterfly shafts, idle drops.... Maybe time for new seals, eh?



Chacal?...


EDIT: forgot to add, this is on the 750.. So I guess I need a full set for Hitachi's...

 

You rang?


THROTTLE SHAFT REBUILD PARTS:


THROTTLE SHAFT SEALS:


aaa) Aftermarket Hitachi HSC32/33 series carb THROTTLE SHAFT SEALS (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........



THROTTLE SHAFT HARDWARE:

v5) Aftermarket Hitachi throttle Butterfly Valve Mounting Screw. Each round aluminum 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 both a 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.

Also, unless you have reasons for doing otherwise, I always recommend upgrading the butterfly valve retaining screws to the 18-8 stainless steel HCP2561 button head hex-key style-----they are more durable than stock phillips headed plain steel, and much easier to remove in the future if the need ever arises.


HCP1347 aftermarket Hitachi butterfly valve retaining screw, pan-head standard alloy steel screw with a phillips-drive, each:
$ 1.00

HCP1347SET2 aftermarket Hitachi butterfly valve retaining screw, pan-head standard alloy steel screw with a phillips-drive, set of 2:
$ 1.75

HCP1347SET8 aftermarket Hitachi butterfly valve retaining screw, pan-head standard alloy steel screw with a phillips-drive, set of 8:
$ 5.00



HCP1348 aftermarket Hitachi butterfly valve retaining screw, pan head 18-8 stainless steel screw with a phillips-drive, each:
$ 1.50

HCP1348SET2 aftermarket Hitachi butterfly valve retaining screw, pan head 18-8 stainless steel screw with a phillips-drive, set of 2:
$ 2.75

HCP1348SET8 aftermarket Hitachi butterfly valve retaining screw, pan head 18-8 stainless steel screw with a phillips-drive, set of 8:
$ 10.00



HCP1349 aftermarket Hitachi butterfly valve retaining screw, low-profile hex-drive allen-head screw made from 18-8 stainless steel, each:
$ 1.50

HCP1349SET2 aftermarket Hitachi butterfly valve retaining screw, low-profile hex-drive allen-head screw made from 18-8 stainless steel, set of 2:
$ 2.75

HCP1349SET8 aftermarket Hitachi butterfly valve retaining screw, low-profile hex-drive allen-head screw made from 18-8 stainless steel, set of 8:
$ 10.00



HCP2561 aftermarket Hitachi butterfly valve retaining screw, low-profile hex-drive button-head screw made from 18-8 stainless steel, each:
$ 1.00

HCP2561SET2 aftermarket Hitachi butterfly valve retaining screw, low-profile hex-drive button-head screw made from 18-8 stainless steel, set of 2:
$ 1.75

HCP2561SET8 aftermarket Hitachi butterfly valve retaining screw, low-profile hex-drive button-head screw made from 18-8 stainless steel, set of 8:
$ 5.00



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

 

See? This is the kinda stuff that never ceases to impress me about this site.

Would that our elected politicians respond to the critical needs of this nation the way Chacal responds to the needs of this Forum.

I rest my case.

 

Chacal, you got PM!

 

Question... Do the seals need to be glued into the carb bodies? Or just pressed in?

 

Pressed, but not much "pressing" is necessary. A little dab of o-ring lube (silicone, non-petroleum grease) isn't a bad idea, either.

 

You don't use glue.

You do use a liberal amount of lubrication.

I use Marvel Mystery Oil.
Mostly because I like the way it feels and smells.
I like the color; too. Red.

I wipe all my tools down with it.
I have some in an Oil Can and use it on Carb Linkages
Cables

 

Excellent. I'll pick up some Marvel from one of our fine parts stores tomorrow.

This will be the first time for me to break a carb rack. Gotta do it some time or another though... 8)

 

i strongly suggest you pickup a set of screwdrivers from chacal as well. American philiips have a bad habbit of stripping those tiny heads of the screws used to hold the butterflys into place. I new set of hex head screws wouldn't hurt either.

 

I ordered the hex-head screws from Chacal along with the seals... the rest of these carbs have been converted to hex-heads by the PO. It does make carb work a lot easier.

 

i use it in my hair AND on my steak.

 

Then aren't you glad I documented the process?

 

very nice write up schmuck. any more pearls of wisdom you've got lying around

 

Not to be a smart ass, but we used to call the e-clips, Jesus Clips. Cause thats what you say when you are not careful enough and they go flying off and into some little crevis on the floor. So do be careful when removing them

 

Redfire, I like your avatar!

 

Absolutely. I'm printing it out as we speak.

Thank you!

 

Fantastic photos schmuckaholic - I saved that fro future reference, replacing all these seals is on my agenda. Thanks!

 

thanks chacal, I think I borrowed it from a fourwheeler forum. didn't see anyone using it here, and I liked it better than most of the smiley faces