link & sinc

[okcadman]

1978 70 HP with carb problem: starts fine, runs on muff ok, plugs news, spark good, but when in lake and advance throttle, the engine rpms drops and motor acts like it being choked out. Overhauled carbs, replaced fuel pump, new fuel tank and lines. Same problem, but I did not know about the "link & Sinc". What is it and could this be my problem now?

 

[ob]

Re: link & sinc

Link and synch refers to the synchronization of the carburetor linkage as it relates to the advance of the ignition timing.Best to refer to an engine specific manual for the specifics while performing this critical adjustment.The idle mix of the carburetors is also an item that will cause the symptom you describe.

 

[wilde1j]

Re: link & sinc

Timing doesn't change, unless someone mucked with it. If you need link and sync, try doing a search here for Joe Reeves procedure. You don't have to run the engine to do it, but you need to know the advance setting for your motor, which is in the shop manual. You have an OEM shop manual, right?

 

[okcadman]

Re: link & sinc

I have a shop manual, however the timing was not changed, only worked on cleaning carbs, replaced fuel pump, lines and tank. It is my understanding the carbs do not have an adjustment (factory preset).

 

[ob]

Re: link & sinc

I wasn't refering to the idle and full throttle timing settings,but the varying timing that occurs throught the throttle range.The carburetor linkage adjustment has to be in synch with the advance of the timer base as well as each carburetor flap opening and closing in synchronization.Link and Sych.It's critical.If its out of adjustment the engine will not respond correctly to throttle up.

 

[Silvertip]

Re: link & sinc

The carb throttle plates must all be fully closed at the same time and be perfectly horizontal at wide open throttle. If these aren't sync'ed properly you have performance issues as well.

 

[DHPMARINE]

Re: link & sinc

Also the throttle shaft holes may have too much wear. If you can take the throttle shafts and move them up and down a lot (I have no specs) the carbs may be sucking in too much air to properly let the engine run.<br /><br />DHP

 

[okcadman]

Re: link & sinc

Thanks I will check out the timing; but it seems strange that it worked fine for about 30 minutes then all of the sudden it start choking out and decreasing in rpms like it is out of fuel. That is why I consentrated my repair efforts on the fuel system.