adjusting screw , clutch arm for a Ambo 69

[arveno]

Hi All ,

I ordered the adjusting screw,clutch arm part # 12034001 from Harper, but it does not fit the arm, somehow it is too big or the arm's hole is too small.

I ordered another one from MGcycle ( see link below ) it is same diameter as the one got from harper so it does not fit.

http://www.mgcycle.com/index.php?main_page=product_info&cPath=193&products_id=437

whats wrong with my clutch arm ? ( could it be the PO welded the hole in the arm and then drilled it smaller because he did not have the original one ?

Bike is a 69 ambo , when i got it , adjusting screw was missing.

Thank you very much for your help,
Marco

[Antietam Classic Cycle]

My '69 doesn't have an adjusting screw, only a rounded "nub", same as the V700. Part no. 1209 0400, #23 on page 29 here: http://www.thisoldtractor.com/mg_manuals/spare_parts_catalog_700_1ed.pdf

[arveno]

My '69 doesn't have an adjusting screw, only a rounded "nub", same as the V700. Part no. 1209 0400, #23 on page 29 here: http://www.thisoldtractor.com/mg_manuals/spare_parts_catalog_700_1ed.pdf

Charlie , thanks for the info , but is that "dowel" screwed into the clutch arm's hole ?

And where can i find one ?

thanks a lot
Marco

[crc]

is there enough meat in the arm to drill and tap to the size of the adjusting screws you were sent? that maybe the easy option

[Jimbolong]

Why not just go to the hardware store buy a screw that fits the hole?

[arveno]

>not sure if there is enough meat to drill and tap , it's gonna be a very thin spot.

>And yes i can use a screw off the hardware store but it won't be rounded on one side.

[racasey]

Why not just go to the hardware store buy a screw that fits the hole?

A common metric thread fastener from a hardware store would be in the property class of 8.8 and far too soft for the clutch throw out application.  The rider would be subjected to very frequent adjustments from rapid wear.

Ciao,
Dick

[Chuck in Indiana]

>not sure if there is enough meat to drill and tap , it's gonna be a very thin spot.

>And yes i can use a screw off the hardware store but it won't be rounded on one side.

Definitely not enough material to drill and tap. I'd say that a Distinguished Previous Owner tapped yours for a hardware store bolt. That may be your only option with what you have..

[arveno]

or put hand in my wallet and get this from harper.

http://www.harpermoto.com/12090201-12090100.html

[Chuck in Indiana]

I"d say at this time, you've got nothing to lose. I'd get a 10.9 with the proper thread and very carefully (you don't want it to get hot and temper it) grind a ball nose on the end. If it turns blue, it's ruined. Try again. Have some water ready to keep it cool. Also, since it *may* be a bodge, check first to see if it is an SAE thread. At any rate, get the hardest bolt you can and have at it. <shrug>

[John A]

If I remember correctly there was several different arms used on Ambassadors. I sold off all my loop frame stuff 20 years ago so I can't go scrounge through the pile of arms but I'll bet somebody around here has seen this

[acogoff]

     I think you will be surprised how long a homemade screw will last. It isn't like it is pounding like a rocker arm adjuster.

[Antietam Classic Cycle]

or put hand in my wallet and get this from harper.

http://www.harpermoto.com/12090201-12090100.html

Be aware that there are several variations of 4 spd clutch arms. The distance from the pivot point to the adjusting screw changed, likely due to the change from the original 20 mm throw-out bearing to the later 22 mm. I would advise measuring yours - center of the pivot hole to the center of the adjuster screw hole and make sure whatever you buy is the same. Otherwise, the adjuster screw will be trying to cock the outer body of the throw-out bearing sideways every time the clutch is operated and the bore of the transmission rear cover could become worn oblong over time.

If it were me, I'd do as Chuck says - buy a 10.9 hex head cap screw and machine the head of it domed (or have it done if you don't have the capability). It's likely a "normal" M6-1.0 thread.

Edit: another option would be a "swivel set screw" like this: http://www.mcmaster.com/#93339A214 This may not be the correct length you need, I'm only posting it as an example. Thread it completely through the arm and put a locking nut on the outside. Should work, even though there isn't a flat spot machined for one.

[arveno]

If it were me, I'd do as Chuck says - buy a 10.9 hex head cap screw and machine the head of it domed (or have it done if you don't have the capability). It's likely a "normal" M6-1.0 thread.

Charlie , i think you and Chuck are right on the money...i have a little shop at work , i can machine a screw and call it end of the day . ( also gonna save 60 bucks ) ;D
thanks a lot for the advice .

 ;-T

[Chuck in Indiana]

Charlie , i think you and Chuck are right on the money...i have a little shop at work , i can machine a screw and call it end of the day . ( also gonna save 60 bucks ) ;D
thanks a lot for the advice .

 ;-T

No need spending money unnecessarily..  ;D :BEER:

[Jimbolong]

A common metric thread fastener from a hardware store would be in the property class of 8.8 and far too soft for the clutch throw out application.  The rider would be subjected to very frequent adjustments from rapid wear.

Ciao,
Dick

Thanks for that information.  Might save me from screwing up somewhere down the line.

[Hahnda]

I posted this over on the Loop Group but will post it up here also.

I think the earlier ones used 12090400 as Charlie said and then 12090402.
http://www.thisoldtractor.com/mg_manuals/spare_parts_catalog_750_1aed.pdf

I have a few of the 12090402.