HD8 SU Carburetor removal

[pkmh]

Hey thanks Keoke for you input regarding the diaphragms, especially.

I will have to admit to something I did regarding rebuilding the carburetors, a lesson of what not to do but luckily how I escaped causing any damage and how I came up with a simple yet effective solution in reversing the reassembling procedure (butterfly assembly). And yes, I know I will get one of those waving, naughty index fingers, most likely. Fair enough.

The only reason I am doing this so that hopefully no else blunders, but if so, then there is at least one "simple" way to undo what I've done. And if there is anything else one wants to add, then good enough.

I will get back here eventually.

Paul

 

[pkmh]

Okay, for whatever it's worth to anybody, The following is an example of doing something you may wish you never did but if you do, then there is a solution that has worked for me.

Case in point, I dismantled the throttle spindle from its shaft assembly from the rear SU the other day.

Naturally, after doing the above, a friend of mine advised you should never remove that. Well, too late for that advice. And even if that's true, I gained the visual knowledge of understanding more what was going on there plus successfully removing all grime from within the shaft and carefully clean all pieces. Plus, after reinstallation, ending up having less play of the spindle inside the shaft. My other big plus with all this was that nothing was damaged in the removal process and reinstallation, lucky for me! But again, I am not advising anybody to do as I did.

With that aside, my only real dilemma with the whole process was how to reinstall those existing soft nylon(?) bushings surrounding the throttle shaft. These bushings are very soft (in my case, anyway) and each have these diagonal slits by design so keeping them into a fixed position as you slide them back through the shaft opening proved to be very difficult by hand (making me sweat and lose sleep over, no less).

In more detail, the physical makeup of the pieces surrounding the throttle spindle (concealed from view and in the aluminum shaft body) and found on either side of the [exposed] butterfly throttle are these very thin "C" style circular clips, then the soft bushings and then these wider and slighter thicker "C" circular clips, all three pieces each side of the throttle forming a sandwich-like composite on the spindle.

Okay, now...I am NOT advising here to do a disassembling of the throttle spindle but for those who will or did as I did, the solution in putting all back together again is as easy as I could make it, without investing in anything other than using simple sewing thread.

1. The spindle can only be disassembled in one direction. In the case of the rear SU and looking down at it with the bell chamber in the 6:00 position, the spindle has been removed to the left. Keep in mind, you must reinsert the spindle to the right, reversing the process (BUT, my advise is to make sure all pieces are where they are suppose to be positioned BEFORE attempting to reinsert). That is, all "C" clips and bushings in between and either side of the throttle (butterfly). IMPORTANT NOTE: When ready to reinsert the spindle, the only pieces that should be on the spindle is, from left to right and in order, are the left end wider "C" clip, the left end bushing, the smaller left side "C" clip and then on the right side of the throttle (butterfly) is the smaller "C" clip. The right side second bushing and larger "C" clip must be off in order to successfully complete the reinstallation through the shaft opening.

(I recommend doing a positioning mockup of all applicable pieces on the spindle mentioned, then leave off the second bushing and Large and wider "C" clip (at the right end). I also would suggest placing the spindle over the carburetor body to determine where pieces will ultimately end up so as to not over tap final right side wider "C" clip. The right side "smaller" "C" clip should remain and in proper position).

2. Now the trick...with the left side bushing in place, take some sewing thread and tie a bow or double knot toward the front edge of the bushing and do a separate application toward the rear edge of the left bushing. Make sure each knot is taut, but not too loose or too tight. The first threading has helped me allow for easier passage of the bushing (gingerly) through the shaft opening and the purpose of the second threading is to prevent the bushing from attempting to slide out of position and over the wider "C" clip. DO NOT exert extreme pressure or force the spindle more as needed into the shaft. As you are sliding through, make sure to remove all threading in its entirety.

3. Hopefully, you are at a point where you can now complete the right side. Apply same technique of using the thread with the right side bushing. As a reminder, the spindle should be fully installed within the shaft. Carefully slide the bushing as close as position next to the smaller "C" clip. then the wider, thicker "C" clip should be tapped into the desired and final position (Do not over tap the wider "C" clip). You should see enough from the side where the bushing has ended up, given you enough of a clue where to stop the final "C" clip (reread about the positioning mockup part, if necessary).

4. Apply the throttle with the two set screws and carefully flare out their tails. Make sure throttle freely opens and closes as it did (or should of) before.

THAT"S IT IN A NUT SHELL.

I welcome any criticism to the above. Because of what happened to me, I figure I share my experience and help in any way I can. I do not pretend to know all that there is to know so please tell me if there is something else I should do myself. I am still in the rebuilding phase so any advice is greatly appreciated.

Paul

 

[Keoke]

4. Apply the throttle with the two set screws and carefully flare out their tails. Make sure throttle freely opens and closes as it did (or should of) before.



Make certain that the butterflies are not worn and are center in the carb body.

Alternatively, to the Teflon bushes you can have Sealed ball bearings installed in the carbs.
---Keoke

 

[anthony7777]

:lol:
Truthfully,Rich:
I do not have any photos I don't think digital were invented then. Additionally, I did not want any memories of the misery [$$$$$]] I went through -OK--Keoke-

keoke, when you did this job, they had not even yet invented rocks!,,, im swimmin in da pool, just swimmin in da poool, what a glorious mornin just swimmin in da poool!...

 

[Keoke]

keoke,--WOT!!!

when you did this job, they had not even yet invented rocks!,,,


im swimmin in da pool, just swimmin in da poool, what a glorious mornin just swimmin in da poool!...




But i'm ........................Keoke--

 

[pkmh]

Thanks Keoke for your last advice.

To any and all who know the answer to the following, please offer your solutions.

I am at an impass trying to remove the diaphragm from my SU. I have reviewed the one response above about how the diaphragm is held in by tension and when the bottom is removed, the diaphragm should come out.

Well, I have not placed any real pressure in trying to remove it yet and it is not coming out and doesn't want to any time soon. There is a jet locking nut beneath it secured to the aluminum body. One manual (Glenn's) mentions to loosen 1/12 turn the Jet Locking Nut for centralizing purposes.

Would it be dangerous to loosen that nut or is that also going to be part of the rebuilding process?

It would be just a relief to know how to remove the diaphragm safely.

Thanks for any solution!

Paul

 

[Keoke]

Thanks Keoke for your last advice.

To any and all who know the answer to the following, please offer your solutions.--- :confuse:

I am at an impass [ position or situation from which there is no escape ] trying to remove the diaphragm from my SU.--

I have reviewed the one response above about how the diaphragm is held in by tension and when the four screws that hold the float bowl are removed the jet housing " bottom " is removed, the diaphragm should come out.



If you are at this point take your thumb and see if you can push the jet up into the carb body, If so take a knife and separate that old hard worthless Diaphram / jet from the upper half of the carb body.----- :laugh:


Well, I have not placed any real pressure in trying to remove it yet and it is not coming out and doesn't want to any time soon.

There is a jet locking nut beneath it secured to the aluminum body. One manual (Glenn's) mentions to loosen 1/12 turn the Jet Locking Nut for centralizing purposes.


Correct but lets consider it is presently centralized and if we fiddle with it it reqire a special tool to recenter it --LET IE ALONE!!!

Would it be dangerous to loosen that nut or is that also going to be part of the rebuilding process?--Well t can complicate thibngs abit.--

It would be just a relief to know how to remove the diaphragm safely.

Thanks for any solution!----

Paul

 

[pkmh]

Thanks Keoke,

Finally got the diaphragm off by tapping out from above, after removing the suction chamber and needle assembly. Had to do it that way, would not come out from just pressing or pulling against the jet.

Thank you for all your input. From here, I SHOULD be able to finish and then work on rebuilding the master cylinders, etc.

Paul

 

[pkmh]

Well, both my SU's are virtually done, rebuilding wise. Somehow, one of my "needle and seat" assemblies developed legs and walk away. The rebuilding kit I used was more than adaquate to do the entire job.

As far as headaches I had to deal with and I am talking about AFTER removal of the SU's and aside figuring how to put those "soft" bushings back through the throttle spindle as I mentioned earlier on this thread, the other nervous moments was tapping out the old diaphragms, the front SU being much harder than the rear. After cleaning the rest of the jet assemblies in place (not loosening or fiddling with, that is), the new diaphragms slid effortlessly in position, leaving me with the comfort of knowing nothing was bent or scored from removal of the old.

The second headache was dealing with the removal of the front SU's banjo union from the aluminum chamber lid. Loosening just wasn't happening even after doucing with PB Blaster so care not to bend or break the aluminum lid was on my mind.

One hurdle done. Next, the clutch and brake masters, then the hand brake cable (etc., etc.!).

Thanks for all input for the above!

Paul