sq4 valve adjusting screw

[Henning G]

I have just inspected my rocker assembly on my 1939 sq4, and I found that the valve adjusting screws (936-31) have seen better day, and the same for my valve steam end caps (655-34). Unfortunately ”Draganfly” is low on stock on both items. Is there any alternatives? Those at “Draganfly” is for Allen key, don’t know if that’s better than the original square. Wonder if the adjusting screws fits from other bikes..

[paul.jameson]

Do be very careful if you decide to replace these, especially if you have skimmed the surfaces of your head and rocker box. It is all too easy for the tops of the screws to catch on the underside of the rocker box cover, causing loss of compression and a misfire which is difficult to trace. I ended up using 2 thick gaskets on my rocker box cover to cure this - with the original valve adjusting screws. I am now running without the hardened valve stem end caps on several of the valves to gain more clearance. You don't need the hardened caps for the sake of the valve stems as these are hard enough on modern valves so their only purpose is for the valve geometry these days.

[JohnnyBeckett]

hi i got some Allen key adjusting screws from drags and i wasn't happy with them the ball size is smaller and the screw thread is longer and the thread pitch wasn't right they was binding in the rocker so i found some spare ones i had and adjusting screws from other bikes will fit

[Henning G]

Hi, Thanks for you answer. Very interesting news regarding avowing the end caps, and I haven’t thought about the lack of space when fitting the top lid. I did bay a complete set of adjusting screws from Draganfly, but as you mentioned, but they didn’t fit properly, so ending up with a couple of them being round where the Allen key fits. I think I will give the old one a bit of TLC.

[Henning G]

Hi, is there someone that makes new rocker shafts for iron head sq4-898-37 ?