Sticking throttle butterflies IP2

[gripper]

I noticed that when I wound the throttle up towards the top end on the range, (not while running) it sticks open. As I rarely need to go to that position on the throttle, it's not too much of an issue but should I need to wind it on a bit to get out of a sticky situation, It could feed me into a stickier situation. I've managed to get a drop of oil into the spindle area but it doesn't seem to have had much effect. I could fit a stronger spring but that will make the throttle heavier and is treating the symptoms not the cause. Most Japanese bikes use a two cable mech, one to pull the throttle open and the other to pull it closed. This would also be treating the symptoms and in view of the space available would be tricky to do without an engine removal. Any thoughts on this subject?

[Richard Negus]

Dave,I've known throttles become stiff when there isn't enough backlash between the left and right throttle levers. As the spindles are not necessarily exactly in line, being in different engine castings, the end of the adjuster screw can move away from its normal contact spot towards full throttle, backlash disappears and stiffness happens.If you have cast brass Commander levers, then slacken the lower adjuster screw.If you have original IP2 steel levers with one adjuster, slacken the top screw by half a turn to see if that improve things. You will have to return the screw to its original position to maintain butterfly balance. You might be able to bend the lever with a long screwdriver, but a 'proper' fix is an engine-out job ...........You might also be lucky and have one of the few steel levers modified to have two adjuster screws.

[gripper]

Throttle spindles not in line! whatever next? I did think along those lines and slackened the balancing screw off, but maybe a bit more will reveal all. Thanks Richard. I might rob the twist grip and cables from my sons Honda but the routing for the "pull closed line may involve a pulley or be about 6ft long.