Chrysler 90HP electrical - heat but no action

[Screaming kiwi]

Hi Guys,

I have a 90HP with an electrical issue. When I attach the battery;
- the starter won't engage
- there is heat coming from somewhere
- i can hear an electrical buzz near the wiring loom block

I have a few spare electrical bits off another engine so I thought I start swapping out the CDI, Rectifier etc and see if it is one of those but I thought someone on the forums might have some advice before I start this process in case I fry a good CDI.

Any advice welcome because I'm not so good on electrical stuff. I do have a power meter so can take readings if required.

Cheers,

Grant

 

[jerryjerry05]

Battery hooked up right?(had to ask)
Battery hot?
Battery bad?
Harbor Freight has load testers usually under 25$

Sounds like a loose ground on the block.
Does the starter turn?
Does the Bendix engage the flywheel?​

Guessing.
Try, turning the Bendix by hand and see if it goes up to the flywheel.
Any rubber or black pieces around the bottom of the Bendix?​

Under the starter where the ground connects to the block, check to see if the screw is tight.
Check the battery cable for swelling or bad spots, look for bad connectors.
The solenoid can buzz.
Spray some WD in the key switch.
Do a compression test.

ANY more info or description will help????????

A year and model# will help too.

 

[Screaming kiwi]

Hi, thanks for the ideas. The model is 90hp 1975 907HA.
- battery is good
- negative cable is a bit suspect in that it looks like it has been crushed at some point
- no movement at the starter or bendix.

I'll check the starter via jumping it rather than via the key.

Cheers

 

[Frank Acampora]

You have the 3 cylinder, two piece lower unit engine. The lower unit should be 2 to 1 ratio.

Before going crazy, check that the neutral interlock (on the CD side, under the bottom carb) has the white button depressed. Check that shift linkage is actually in neutral when the control handle is in neutral position. Check that the two yellow wires are not broken or shorted.

Some CD boxes did hum or buzz with the key on and yours may be one. However, your description of "heat" puzzles me. Is the starter heating? Is there a short and a wire is melting somewhere? If you turn the flywheel by hand with the key on, do you get spark?

 

[oldboat1]

See if you can find the heat source (short) with an infrared heat gun. Agree some more troubleshooting called for before risking the other parts.