Hi all
Can anyone tell me what kind of torque wrench is available for the hidden cylinder head nuts on my c 15?
Cheers Chris
I've never found the need to use a torque wrench to tighten the cylinder head nuts on a BSA unit single and don't really know what the torque settings should be? However, on my Rotax engined single, you have to torque down it's partially hidden cylinder head nuts and, to do this, you have to use a special tool. This looks like a 4" long brake lever arm and basically has a 3/8" square hole for the torque wrench at one end and a hex hole at the other end to fit over the nut. If you operate the torque wrench arm at 90 degrees to the special tool then the wrench will read the correct torque imposed at the nut.
The picture shows the Rotax special tool. In fact, it comes with a 1/2" hole in the middle for the torque wrench drive and has two sizes of starred holes at either end for the two sizes of cylinder head nut used on the engine.
Ive seen a special tool in a workshop manual similar to
https://www.zoro.co.uk/shop/hand-tools/torque-wrenches/torque-adapter-3-8inch-13-mm-12-edges/p/ZT1741017S?utm_source=google&utm_campaign=pla%2B%7C%2BHand%20Tools&utm_term=ZT1741017S&utm_medium=pla_css_2&targetid=pla-1644770097562&loc_physical_ms=1006554&dev=c&gclid=Cj0KCQjw9ZGYBhCEARIsAEUXITUKlogFbhRkO4jjBLe1IcxiC3r-knegJZs5lBfrV7pPrmEVG565Kd8aAr9-EALw_wcB
but the hex head is slightly thicker
The Rotax tool is about 1/4" thick and pretty substantial. As said, you have to be careful to use these tools properly otherwise the torque wrench will apply much more torque than indicated.