2004 Johnson 225hp to Suzuki part number

[placerville]

I recently purchased a 22 Boston Whaler with a 225 hp Johnson 4 stroke model
number j 225px4sp. The boat sat in a field for several years. The motor runs well but I have several issues with the controls and tachometer:
Tachometer started fluctuating wildly, indicator lights started cycling then now don't read at all.
I don't have very fine control of the throttle at low speed.
Trim switch doesn't work on remote control.
I was thinking of just changing out the remote control and the tachometer.
I can't find those parts on the Johnson parts page. Can I use the Suzuki 225 equivalent? how do I know which Suzuki model is the same.
Any thoughts would be appreciated.

[Moonlighter]

A 225 Johnson 4 stroke is the same as the SUZUKI DF series of that same year so parts should be fine to select on that basis.

Id suggest you first look at the wiring harness, it could well be the cause of your problems. Check it from end to end, and everywhere you find a group of cables bound or rpgrouped together in the harness, open the bindings and you will likely find some cable joins inside there. There have been many documented cases of those joins getting corroded and causing all sorts of problems with instruments and motor reliability.

Of course you could change the entire harness but it may not be necessary if you find the problem joins.

These engines are very sensitive to voltage - need to be certain that you've got good batteries, clean and shiny battery connections, battery cables are good condition, and as i said earlier the harness and all joins are inspected and reconnected to make sure they have no corrosion in the join or nearby wiring. And all connections under the cowl and clened and retightened as well. Especially any from the starter motor to the ECU.

There is an important white battery sub-wire to look out for too. It should be connected to the starting battery or to the positive side of the main battery switch. This poswers the ECU: bad connection = engine wont go or will play up. Sime dealers took shortcuts and connected this wire under the cowl to the starter motor positive pole, it should be to the battery, not there.

The control boc may need to be pulled apart, cleaned greased internally and put back together if its been sitting in a field for several years. Or, the shift cables may be stuffed and need replacing in that situation as well.

Hope this helps. Let us know how you go.