2003 F90TLRB Tilt Problem

[newboater]

I have a weird tilt problem. Can tilt full up or down once, then don't have any tilt. Let it sit overnight and I have tilt for a minute or so and it stops again. Relays and relay contacts check good. I see there is an internal circuit breaker in the tilt motor. Can it behave that way? The way it looks in the diagram I'd think it would be a fusable link.

The tilt motor resistance (blue to green wires) varies from around 250-400 ohms which seems odd. I can't find a specification anywhere but since both brushes are in contact with the commutator I'd think it should be a pretty low value.

Any suggestions?

Bob
Cape Coral, FL

[rodbolt17]

sounds like the thermal cut out inside the motor is dirty.
sometimes you can disassemble,clean and reassemble the motor.

[newboater]

Thanks Rodbolt !! Will try to tackle the tilt problem tomorrow.

I also have a tach issue where the RPM needle on the tach will quickly swing to max RPM and come back to the running RPM intermittently.

The tach connections and wiring harness connectors in the console are tight and clean. The tach signal came from the regulator on a 50HP Honda I had in the past but I can't find anywhere in the Yamaha F90 wiring diagrams where the tach signal actually comes from.

Can you tell me where the tach signal originates?

[rodbolt17]

the F90 tach signal is ECU generated.

[newboater]

I don't have a trailer so I broke down, got in the water and found the cause of the tilt problem this weekend. The cover on the tilt motor had rusted through on the back side. When I removed the cover the armature stayed in the bottom of the tilt assemblyy, so I just put the cover back on until I can get a new motor. I 'll definitely pay more attention to washing that area down from now on.

Any chance you know what signal(s) the ECU looks at to generate the tach signal?

I'm guessing it would have to be the pulser coils, the regulator output or the TPS Sensor. It seems like the pulser coils would be the most accurate, but I know the regulator voltage was used on a Honda motor I used to have. I service medical equipment so I know different OEMs go about achieving the same results by different methods, and don't hazard to guess.

Too bad you can't get a schematic for the CDI/ECU. I'd really like to see what's going on in there. Will probably scope them all, as well as the lighting coils just to see if there is anything that's skipping a beat or dropping out, since it also sounds like it's missing intermittently at any or all RPMs.

Fire it up one time and it sounds like it's missing. Fire it up the next day and it sounds and runs fine. I hate intermittents. It's much easier to fix broke.

Thanks again for your time.