Why can't I set my timing?

ThomW

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Hey guys. I am completely stumped here. I have been working on my 2000 Mercury 200hp outboard, carbed model. I replaced the trigger, and now I cannot get the timing set! I am trying to set it to the cranking specs, but It will only go from 0 to maybe 10 BTDC and no further. What in the heck could be causing this issue? It doesn't a separate idle stabilizer that can be disconnected. All plugs are out and grounded. Light is hooked to the # 1 plug. no matter how far I move throttle arm and adjust max screw, it can't get it to advance past 10 BTDC.

I am really stumped and running out of ideas. Any and all ideas or things to try would be greatly appreciated, as I really wanna be on the water instead of in my driveway on the boat! Thanks as always!
 

Dukedog

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Oct 6, 2009
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this is a cdm motor, right?
if trigger has "full movement front ta rear" and max doesn't change probably down ta one of two things... bad trigger or control module....
 

ThomW

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Hey Duke. It does have the CDM's. Trigger was just replaced, brand new from CDI Electronics. I guess that doesn't mean it isn't crap, but I assumed it would be working. Trigger has full front to back movement.
Timing will advance, but only to maybe 10 BTDC. How can I test the Control module and/or trigger to see where the problem is? New Control is almost $400, so I obviously wanna make sure before I buy one! Thanks again.
 

ThomW

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Well...no compression in the #1 Cylinder. That's never a good thing. Might explain my issues though.
 

racerone

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I guess that is why I say check compression first when trouble shooting a motor.
 

ThomW

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Haha. Yep. Didn't realize there was an issue. Just bought the motor. Replaced the trigger because of bad wires and was just trying to set the timing. Once I couldn't get timing to adjust, started looking elsewhere. Never a good thing to find, but at least I now what the problem is. Now I guess I pull the power head and see what I see.
 

ThomW

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This might be a silly question, but would the lack of compression in the number one cylinder be the reason I couldn't set the timing, or is that another issue? I am trying to wrap my head around it. Timing is based off of the trigger and plug firing, right? So what role would compression play in the setting of the timing?
 

ThomW

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One more question--might be a dumb one

Hey everyone. So I have been having issues with my 2000 Mercury 200hp outboard (carbed) model. I was going nuts trying to get the timing set, and couldn't get it past 10 BTDC.

Last night I discovered that I had zero compression in the #1 cylinder. All other cylinders were fine. My question is this--would having zero compression on that one cylinder--the one the timing light hooks to--be the cause of me not being able to set the timing? I get that the timing is based on the plug firing, and the trigger should change timing, but how, if at all, would no compression affect my being able to set the timing? Or is the timing another issue all together?

As always...thanks!!!!
 

racerone

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About the only way that timing goes out of adjustment is when an owner starts adjusting it.-----Timing is " fixed " for the life of the motor.---Perhaps the PO was adjusting linkages to try and compensate for a dead cylinder.
 

ThomW

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Perhaps. I had replaced the trigger, so I was checking to make sure timing was still to spec. However, it was reading 0 to maybe 3 BTDC. Even when adjusting the max screw (while holding throttle arm against max adjustment stop) I couldn't get it to advance past 10 BTDC. Is that a result of the dead cylinder?

I was surprised to find the dead cylinder, as the boat would idle great. It just wouldn't go over 2500 rpms or so.
 

Canufixit2

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May 20, 2016
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OK - I don't now your engine - but have some basic things to ask/check.

Your flywheel is KEyed Correct?? No chance it's not on the correct position on the crankshaft?

From what I see for my 1996 60hp on parts diagrams and manuals - did you pull the stator and get it back in the same position?

Again - from what I see from my manuals - the trigger picks up the signal from the inside of the Stator?? Any chance the stator is bad and sending the wrong pulse to the trigger ??

as for cylinder # 1 - Wow! I take it it's a blown piston crown or severely damaged walls/rings ? Let us know what you fined.

What was all the compression test readings???

Check your top crank seal for leaks too ... just my opinion
 

racerone

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Fixit2---The trigger DOES NOT pick up signals from the inside of the stator.----Review your manual.
 

Canufixit2

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OK - I thought since the magnets are on the outside edge of the Flywheel and outside the stator - how does it pick it up ??
 

Dukedog

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a dead cyl. won't have anything ta do with timin'.... but thats a moot point till ya get tha block fixed..

The trigger assembly (also mounted under the flywheel) has 3 coils. Each coil controls the spark to 2 cylinders -1 cylinder each bank. The flywheel also has a second set of permanent magnets located around the center hub. As the flywheel rotates, the magnets pass the trigger coils producing AC voltage.
 
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