Trigger test results 1995 90 hp Merc

[sorensonrg]

I tested my trigger for my 3 cyl 90 hp merc. The purple and white wires ohmed over 1000 but the tan was 700 ohms. All wires tested infinite to ground. The tan and white wires both had failing insulation at the bullet connector, I installed a piece of heat shrink tubing to beef them up until I determine if I need to replace the trigger or just reterminate.

I don't know much about triggers except that I held mine in my hand; my total knowledge is listed above. Would a bad trigger allow my motor to run but run without good hole shot and no top end? I'm getting up to 3400 rpm (WOT should be 5500) without kicking or other bad symptoms but it feels like the throttle needs to keep rotating. I'll post results of recommended actions.

 

[sorensonrg]

Re: Trigger test results 1995 90 hp Merc

I noted a small (1/4") vertical "crack" on the inside of the trigger. Looks like plastic. Is any crack too big?

 

[verado7]

Re: Trigger test results 1995 90 hp Merc

replace the trigger at the very least - a crack is not good and if you want to really test it - remove the wires from the pack and use a regular voltmeter -you should see 4-5 volts while cranking ( dont worry the engine wont fire with the trigger wires off the pak) yes the trigger can give you a bad hole shot and prevent the engine from reaching full rpm's - it is after all what controlls the timing/spark output as it rotates with the throttle .

 

[sorensonrg]

Re: Trigger test results 1995 90 hp Merc

Thanks for the reply. Dumb question......am I using the AC scale? I assume I'm reading from one of the three trigger leads to the black/white bias wire?

 

[Dave1027]

Re: Trigger test results 1995 90 hp Merc

The book says to disconnect all trigger leads and read the resistance between the three leads and the black/white lead. Resistance should be 1100-1400 ohms.

 

[verado7]

Re: Trigger test results 1995 90 hp Merc

ac scale yes

 

[sorensonrg]

Re: Trigger test results 1995 90 hp Merc

Tested trigger again with two meters to ensure results were verified. When I touch the colored wire (with the other lead to the black/white) the ohms start high (ranging from 1800 to 1600 ohms) and start decreasing rapidly to 1023-purple, 701-tan and 1267-white.

On a second front I can't get good readings out of my stator. green/white to white/green ohms was 0.74 and infinite to ground for each then 1-2 with a DVA while cranking and 140 AC using a normal voltmeter.

I also tested the black/yellow out of the switchbox to ground. Got extremely small readings in both off and on positions (0.03 volts) but infinite ohms in both positions. Test said 0 ohms in off position should be the reading. When wire was unplugged boat would start and not stop with the key, had to use the enricher to kill it. Starting points would be appreciated!