3116 Tach issues

[EKM]

Finally got my turbo straighened out but the starboard tach seems to be reading high. Is the eng synro unit independent or does it feed off the tach values? This issue is new. I assume they are electronic units so they have a sender. If I just use the port value and match the starboard throttle with the eng synro unit, it does not feel balanced.

How do you troubleshoot?
Thanks...Ed

 

[fwebster]

The tachs on 3116's are Teleflex ubnits that use a sender located on the bell housing. The sender counts teeth on the flywheel and it is a bullet proof design, except for the Teleflex tachs which have about a 5 year useful life before going nutty. The solution is to replace the tachs and your options are another , later Teleflex or you can do as many of us have done and switched to electronic digital tachs from Aetna. They cost a little more but are well worth the difference. They are direct replacements and connect directly to the Sea Ray wiring harness.....you will remove the light bulb from the old tach wiring and tape it out of the way since the Aetnas are internally lit. The only down side is that the Aetna with their trim bezel is smaller than the hole in your dash panel so you will have to either replace the panel to make a filler ring. I chose the new panel approach and I believe OSD9 chose the filler ring method because his panels were good and did not need replacement.

If you have a Glendinning synchronizer, you have a sender located in t he center of your harmonic balancer at the rear of your engines. It is cable driven, not electronic, and is a completely independent stand alone system and has no interface or connection to the tachs or the sync gauge, if you have one on your boat. If the synchronizer isn't holding the same rpms, there are adjustments in the gold box on the bulkhead but you probably need to read the manual before changing anything.

 

[techmitch]

Did you replace 1 turbo or both? Not sure how much difference it would make, just thinking out loud here.

 

[ktcanuck]

Frank, if I have a synch gauge and a synch switch does that mean I have a Glendinning synchronizer? In the limited space on the 420AC I haven't seen anything on the throttle cables that appears like one yet.

Keith

The tachs on 3116's are Teleflex ubnits that use a sender located on the bell housing. The sender counts teeth on the flywheel and it is a bullet proof design, except for the Teleflex tachs which have about a 5 year useful life before going nutty. The solution is to replace the tachs and your options are another , later Teleflex or you can do as many of us have done and switched to electronic digital tachs from Aetna. They cost a little more but are well worth the difference. They are direct replacements and connect directly to the Sea Ray wiring harness.....you will remove the light bulb from the old tach wiring and tape it out of the way since the Aetnas are internally lit. The only down side is that the Aetna with their trim bezel is smaller than the hole in your dash panel so you will have to either replace the panel to make a filler ring. I chose the new panel approach and I believe OSD9 chose the filler ring method because his panels were good and did not need replacement.

If you have a Glendinning synchronizer, you have a sender located in t he center of your harmonic balancer at the rear of your engines. It is cable driven, not electronic, and is a completely independent stand alone system and has no interface or connection to the tachs or the sync gauge, if you have one on your boat. If the synchronizer isn't holding the same rpms, there are adjustments in the gold box on the bulkhead but you probably need to read the manual before changing anything.

 

[fwebster]

Look on the bulkhead in front of the engines for a gold coloed box about the size of a shoebox with red cables running into it from above and out of it to the engines. You will also have a cable running from the center of your crankshaft attaches in the middle of the harmonic balancer if you have a Glendinning.

Sea Ray also used a Sturdy engine synchronizer on some boats where space and set up suited the deign better, but I have never seen one on a Cat powered Sea Ray.