Engine swap questions

[mstahl1171]

I just swapped out my old 1990 Johnson 140Hp with a 1988 Johnson 150.Everything works as it should except the Tach. I have the old Tech Series gauges on the boat. The tach will not read @ 1000 rpm...but if i bump the throttle up to 1500 rmp...works fine. I know the tach worked fine with the other motor. My other boat that I removed the 150hp off of also had a tach that worked fine the other day before i removed. I know I need to check for voltage on the gray terminal and will when i get home. My question is this...is there a pole setting on the back of the gauge? Just asking before I tear apart my console.

Also...had a warning horn that was 3 beeps 1/2 second apart....then 10 second pause and 3 more. Shut engine down and found nothing. Plenty of oil in the tank,....restarted...seemed fine. Ran at idle for 30 mins in the slip with no warning sounds. Anyone know what that signal may be?

Thanks

 

[emdsapmgr]

The tach setting is the same for both engines, so that's not part of the issue. I'd be suspect of the combination rectifier/regulator on the V6, even though it worked on the other boat. Some testing may show something odd. The intermittent beeps sound like an oil tank issue, though both engines use the same part number oil pickup in the tank. It's normal to hear a low oil warning beep for 1/2 second every 20 seconds if the tank is actually low. So, not sure just where the beep sequence comes from on your V6. The factory service manual is not much help on this issue. Another option: swap oil tanks as you did the engines-before going into much more analysis.

 

[mstahl1171]

Yea...my factory manual is lacking on the VRO signals also. I did check the tank...all is good. I ordered a rebuild kit for the VRO just incase the pump is starting to go. Its never been serviced so I decided to do it for the peace of mind. I did check the regulator. No voltage on the gray wire till the RPM comes up...must be a regulator problem...ugh...having to pull the flywheel to change...wish the placement was in an easier spot....:laugh:

 

[mstahl1171]

After an afternoon of hard core troubleshooting...:lol: I found that my engine wire harness is bad...some wires have great looking outer jackets but the copper wire is almost gone. So...I have made my own harness and all my weird little horn signals and sketchy tach problems have gone away!!