Scooterotica

Just put together a 66mm bore smallblock SR motor but the fekking head keeps coming loose after a few miles.
Tried the long Broady head nuts with plain washers to no avail.
Any other ideas???

A small dab of Loctite, maybe. I know that's not an ideal place to put Loctite but it might work.

I have not heard of head nuts coming loose Bofs, so I am a bit mystified. The studs are expected to stretch , but not to the point where the nuts come loose. The stretch is the reason why it is recommended to re-torque the head after the first run. Have you done this?

I know lots of people don't bother to re-torque head-nuts and get away with it, but perhaps it would be worth a try.

I'll watch this thread to see what else is offered by way of an explanation.

Hi
I had this on an imola i used silicone sealant on the threads.
never came lose again
regards
mark

Maybe change the four barrel studs for MB ones or P200 ones

Evening Bofs, I had this happen to me,MB nuts,flat washer then torqued to correct amount.I put a spring washer between nut and plain washer,It`s never came loose again.
cheers ove.

Cheers for the tips folks.
Initially was running with the SR type grey base gasket and that just seemed to crush when the motor was running so allowing the nuts to loosen.
So i removed that and went with a thicker ally head gasket, to maintain squish,thinking that would solve the problem but after a few miles running today the same thing happened again. It`s a new one on me too
Will try spring washers,a dab of loctite, some gaffer tape and papier mache tomorrow and cross my fingers

you could try 4 long distance nuts drilled and wired you might have to cut them down a bit as they might foul the head cowl

Are you using stainless nuts or studs? If you are then bin em. They have a different frictional quality to ordinary steel. I hate stainless fasteners grrrrr

tony wrote:Are you using stainless nuts or studs? If you are then bin em. They have a different frictional quality to ordinary steel. I hate stainless fasteners grrrrr

Agreed. Can't pick the little buggers up with a magnet.
Back to the original question: Your studs aren't loose are they?