Synchronising Throttles

[ian38_39]

Does anyone know how to synchronise the two levers on a mercruiser throttle assembly,
the port lever is always about 3/4" ahead of the starboard at the same revs and has to move that 3/4" before it engages, at full throttle both levers are level fully forward and show the same revs.
Engines are Mercruiser 3lt petrols if this makes any difference.

Ian

 

[luckybuoy18]

would love some help too with my volvo [penta engines have the same problem, can you advise if same problem and how does this get sorted out thanks

 

[scottie]

if the gear section is in sync then it should be only a matter of adjusting the throttle cables
the throttle cable willmost likely work on a pull toopen basis with the cable going through a lost motion set up ie youpull the cable through a hole in a lever until the lock nut catches and drags the throttle open so if you have more slack in one engine than the other then the contol will travel further before it starts to open the throttle and travel further to fully open
closing the slack by running the lock nut up and then relocking the nuts should cure the problem
many controls have mirrored have a slight offset in the splines and can never quite be synched

 

[ian38_39]

Scottie
are we talking carb or lever end when you say this, have tried winding the port cable dead tight on the carb linkage to the point that any further raises the engine revs and it is the port engine lever that apears to have the slack in it as this is the lever that needs to be pushed further, it is the same in reverse too.

Ian

 

[scottie]

start from the beginning

the throttles should start to open as soon as you go past the gear indent(click) in either direction

the control end should be fixed and the pivot should screw on to the cable the same ammount on both
this is basic but if you can not see any other cause you have to eliminate the basics

some controls have more than one hole for the the cable end fitting check that the same hole is used in each control

check that the cable clamping points are the same in both sides of the control again some controls have more than one fixing point

std cables have 3" stroke but the throttles will require less
check that the same connection points are used on each engine
and that the clamps are fitted into the grooves at both ends

also check that thecables ends are the same dimensions
the end may have been brocken and the end re theaded

the throttles should start to open as soon as you go past the gear indent(click) in either direction
you can measure the stroke that the carb arms go through check they are the same

 

[Chris_d]

I've never seen any synchronised on any boat, nor a steering wheel put on straight as well. Mind i've never been on new boat either /forums/images/graemlins/frown.gif

 

[Andrew_Fanner]

Having rebuilt one of the rev counters with replacement components I suspect that it reads wrong by some amount. I have reminded SWMBO, and me, on a couple of occasions that setting synchronised engine revs by using both gauges is fraught with peril so I go by the noise. The sticks go in and out of gear at the same spots and that's all I'm led to believe you can reasonably hope to get.

 

[ian38_39]

Good point but there is definately more slack on the one lever than the other as the revs do not pick up untill the lever is a good 3/4" further than the other

Ian

 

[ian38_39]

Will be taking the control head apart on August 25th so will report back any findings, in the mean time any further suggestions would be very welcome

Ian