Adjusting the tickover

[Mad Harold]

Tickover on my boat is too fast.Engages gear with a "thud" and low speed manoeuvring is tricky.

Injector pump ID plate reads CAV DPA 324. The only adjustment I can find,is a long bolt and locknut between the throttle and shutoff levers,which I assumed was the idle adjustment,however,loosening the locknut and unscrewing the bolt about one turn made no difference to the idling speed.Likewise,returning the bolt to its previous position and screwing it in about one turn again made no difference to the idling speed.

Is this the correct bolt to adjust the idling speed?  I can't see any other.There are no screws on either the throttle lever or the shutoff lever.

Any advice will be much appreciated.

[Tony Brooks]

Photo of the top of the pump where the levers fit. there are to designs and also some DPAs on the small BMCs are a different designs.

 

With the talk of a long bolt I think that you have the newer design but there should be two long bolts, one either side of the throttle level boss. One may be under a silver aluminium tube held in place by thin wire and a lead seal. This one limits the amount the throttle opens and should never be touched or adjusted.  The other one that is exposed is the idle adjustment but first disconnect the throttle cable form the pump to ensure the cable is not holding the lever open a little. Do the stop adjustment and then adjust the cable length so t just fits into the lever. Ensure the cable returns the throttle lever to idle but DO NOT over adjust it so it tries to push the lever further closed. If you do you are inviting a fuel leak from the spindle O ring.

 

Still assuming the same pump. If that does not work you need to adjust the idle damper that is the larger hexagon and locknut right on top  f the pump with the 8mm bleed screw it. I would advise you follow the manual for this procedure. Google throws up at least one online source.

[Mad Harold]

Thank you Tony.Will take some photos of the pump today,and try to post them next week.

Forecast for this weekend is good,so I will be off for a cruise.Will have to live with the fast tickover a bit longer.

[Tony Brooks]

If your pump has the two screws I described then do as I suggest. If it does not (may have just one, the maximum seed stop) then the idle is adjusted by what looks like a carburettor mixture screw set at an angle in the turret.

 

If per chance there is no "turret" and the throttle and stop lever work parallel to a sort of rectangular box that is the top of the pump then the throttle will still have the two screws but they are also parallel with the top of the pump and there is no idle damper.

[Mad Harold]

Found the two little screws just forward of the throttle arm. One for slow running the other limits the full throttle movement.I only spotted them by sticking my face about three inches from the top of the pump and using a torch peering around the pipework.

The slow running screw and particularly it's locknut were an absolute sod to get at,I didn't have a small enough spanner,but a 5/16 socket with an extension reached the screw and about an hour with a small adjustable spanner the locknut.

Had to guess the amount of adjustment because of having to disconnect the throttle cable in order to re-position it [as advised in a previous post] so that it was not pressing hard against the stop,and also lying over the front of the engine with alternator and water pump whizzing around,didn't seem a good idea.

Tickover is now much better,although I think it ought to be a whisker slower,but I think I will wait until the scratches and bruises on my hand have healed before doing it again.

Many thanks Tony.

[Tony Brooks]

Must be a 1.8 then. The 1.5 screws are easy to access. It helps to let us know what engine you have, just saying BMC on this forum could be anything from a rare 998cc through the 1.5 & 1.8, 2.2 to the 2.5. On a sea boat it could go up to about 7 litres.