A10 oil pressure relief valve

[JOHNSTONE]

Is the outer bolt on the OPR valve (the smaller one) left or right thread,as no matter how hard I try I cannot get the damned thing undone? I hope a kind person can give me some pointers.

Regards Rich

[Spaceman]

I don't think there is a reason for it to be a LH thread - the pictures I can see of the plug show it with a normal RH thread.

[chaz]

normally the only reasons for a left hand thread are.
mirrors (on modern bikes) wind force will undo one while keeping the other done up.
one footrest, as pushing down on one will undo the nut and the footrest fall down.
crank nut opposite thread turning to crank direction,, as it would come undone.

there may be a few odd ones but these are the most common.
so should be normal on a PRV.

[DAVE BRADY]

Hi,

I have had this problem in the past and held the large size in a vice and a good fitting spanner on the other.  A sharp hit on the spanner loosened it.  If necessary try a bit of heat.

Dave.

[JOHNSTONE]

Many thanks for your replies Gents. Now I know which way I'm going I can give it some welly

Regards Rich

[chaz]

just to give you an idea, Ive got a chainsaw in at the moment, the way the crank runs , someone has tried to remove the crank nut the normal way. luckilly they have stripped the thread in the nut not the crank, I do have to find a left handed nut with a fine thread.
another instance is a phone call from a Ducati Monster owner, asking if I can undo his mirror as he cant get it to move, as he wants to fit bar end mirrors.
after a while he understood the reason I explained to him, but just couldnt get his head around it., yes, left hand thread and it undid.

[JOHNSTONE]

Just a quick update, I have at long last managed to get it apart and fitted a new ball and spring having first thoroughly cleaned it.

Once again thanks for all your advice.

Rich

[TTJOHN]

Rich.

I believe that most A7/ A10 PRVs are of the ball type but the Triumph PRV is the same fit but a better devise, not a ball but a piston type plunger.

TTJohn

[JOHNSTONE]

Thanks TT John I had the same thought and have already purchased and fitted one.

Regards Rich.