Synching twin 4.3's

[Air Traffic]

I have a 1989 Thompson Daytona 270 with twin 4.3's. At low speed the synch guage appears normal but as I increase rpm's it runs very heavy to the port side. It is where I would need to be about 1500 rpm's off on the starboard tach to show the sync lined up. Is there anyway to test a synch guage or should I just go by ear and tachs? Is there anything else than the rpm's that affect the sync guage? Thanks relatively new to this boating thing and only 1 year under my belt with a twin.

 

[gm280]

Re: Synching twin 4.3's

Have you tried swapping the gauges to see if they still are off and if so how much difference? If they still read that the port side is still reading 1500 RPMs more, then your gauges are good and you have some other problem. I would be amazed to see both engines having the exact same power curves. They should be close, but probably not exact... Not familiar with twin engines in anything, I was wondering if they make something that would monitor the two engines and sync their outputs without the user/operator involved other then manually increasing the throttle for actual operation. I know from flying R/C aircraft that they did make such a circuit for model aircraft with multiple engines... Tachometers would monitor the engine's outputs and adjust their individual throttle controls to sync the engines without the flyer having to do anything. JMHO!

 

[Air Traffic]

Re: Synching twin 4.3's

The sync guage is just a single guage with an arrow that fluctuates toward one engine or the other, the tachs show the same rpm's but when you pick up speed the sync guare shows very heavy to port.

 

[gm280]

Re: Synching twin 4.3's

The sync guage is just a single guage with an arrow that fluctuates toward one engine or the other, the tachs show the same rpm's but when you pick up speed the sync guare shows very heavy to port.

Then swap the inputs to that single gauge and see if your problem follows. That will determine if it is the gauge or other issues...