Trim Sending Unit Adjustment and trim lever rod position?

[the brain]

I recently replaced my OMC trim gauge w/ a VDO designed
for Evinrude.



When engine is trimmed in all the way in down position the
gauge reads completely down



however when I trim up the gauge only reads halfway I'm
actually trimmed up too much w/ this reading.



Do I need to adjust my trim sender? I'd like to have a more accurate trim reading utilizing the full sweep of gauge like when fully trimmed down needle is down an when fully trimmed up needle is fully up, is this possible? this would make it
easier to read at WOT.
This trim sending unit is only for the gauges metering correct?
I believe the transom angle determines the trim limiter rods position.
how do I know my trim limiter rod is in correct position?

should the engine be perfectly straight up vertically? it appears my trim limiter is in negative trim already which might effect hole shot performance; additionally, effects how high it can trim upward?



On about three cruises ago the trim engine was making some gnarly (unhealthy noises) could it need fluid?

Past two cruises haven't heard these noises but I use trim sparingly.

Please advice an thanks

 

[HelmutSheina]

You might need some grease in the tilt bushings. It is not hard to check the trim oil level as long as the filler plug isn't seized.

Regarding the trim gauge sender. Assuming you just replaced gauges and left the existing sender in place, it should have read similarly with both gauges if the new gauge is compatible. Hopefully the sender mounting screws will undo, then you can move the sender lever manually and check the gauge response. If sender and gauge are compatible you can reinstall the sender and calibrate it how you want it.

 

[the brain]

You might need some grease in the tilt bushings. It is not hard to check the trim oil level as long as the filler plug isn't seized.

Regarding the trim gauge sender. Assuming you just replaced gauges and left the existing sender in place, it should have read similarly with both gauges if the new gauge is compatible. Hopefully the sender mounting screws will undo, then you can move the sender lever manually and check the gauge response. If sender and gauge are compatible you can reinstall the sender and calibrate it how you want it.

OK will pump some evinrude triple guard grease in tilt shaft.

will check trim motors oil is it filled to top just under close cap?

will adjust the sender trim angle.

not sure abut the trim level angle rod notice the engine trimmed all the way down is just barely in the negative area. should the engine be 100% while on the trailer? thanks HelmutShenina

 

[HelmutSheina]

With the trim rod, set the tuck in angle of the outboard for best hole shot acceleration. You don't want the bow too high or too low, as it slows you down and can be dangerous.

 

[the brain]

You know the previous engine 04 Johnson175HP trim limiter rod is in exact same position upper row closest to pivot point.

however when out the hole the bow would raise very high so I was adjusting trim up right away to compenstate for lower bow (this was a constant nuisance adjusting trim).

I assume this angle created to much negative trim? Not so much bow rise w/ the new ETEC. not being forced to trim up out the hole. actuely I don't need to trim up at all, I now only trim up to gain 1.5 MPH of top speed.So maybe I have the ETEC in close to correct position.

w/ new prop an some other fine tuning if bow raises to much I'll add positive trim one hole at a time.





So having the engine perfectly vertical isn't a factor how high the bow raises?

the orginale OMC gauge was transfered from the donor boat as where the main wire harness. I never got it to work. I connected the new VDO to a unadjusted sender.
Thanks HelmutSheina

 

[HelmutSheina]

You can play with that trim rod for best hole shot attitude, the worst that will happen is the bow will rise too far on initial acceleration and cause "plowing", basically pushing a fat blob through the water instead of planing most of the hull above it.

It would have been left there from factory, waiting for somebody to adjust it if necessary.

 

[the brain]

I only have one more hole to add more negative trim for hole shot improvement. I may test it out.

I have received my brand new stainless steel prop an am anxious to test it out for next shakedown runs.

I've read little about a vessels attitude. I assume attitude is how the vessel sits in water/ and handles while underway. it's desired to have the majority of hull lifted up above the surface basicley tilted backward, result less drag more speed.

next shakedowns:in addition to the wide open runs monitoring the RPMs an speed
I'd like to position an tape a carpenters level at midship probaley my side window to check attitude while underway.

My side widow is parallel w/ the gunnel so I assume the vessel at rest the level will show tilted backward a little
here's my plan
1.while at rest document the level thats the benchmark. .
2. document the level while increasing speed to top speed.
not much listing so I won't bother test that untill I've filled both new saddle fuel tanks thats another story. priority of next shakedowns is RPM speed an now attitude.

please advise on my plan.
Hopefully a expert can see room for improvement. thanks
I actuely think the trim level limiter rod is in the correct position already but if not I'm ready for any improvement.
thanks

HelmutSheina​

 

[HelmutSheina]

Attitude generally refers to the bow position, or longitudinal trim.

Regarding the best bow attitude under way, it is more to do with the engine RPM and boat speed than a particular angle.

The idea is to get the boat planing as quickly as possible by trimming the motor in for the initial hole shot, then once you're up on the plane tilt the motor up to achieve your chosen cruising speed for lowest RPM. If you come up too far, the prop is likely to ventilate, particularly on turns. Once you get the feel, you will be doing it fairly automatically, like operating a car indicator switch.

BTW if you get the trim gauge sender screws out, clean the threads and put some lithium grease or similar on them, they are nearly always seized and they often shear on removal as heat isn't an option there (unless the sender is shot).