What am I missing here?

[ThomW]

Hey everyone. I am going a bit nuts here trying to figure out why I can't get my timing set. I have a 2000 Mercury 200hp (carb) outboard. I replaced the trigger assembly because the wires were rotted out. It started up and idles fine, but wouldn't really take the throttle and would not go above 4000 rpms. I took the carbs off and rebuilt them. I am trying to adjust/check the max timing.

I found TDC on #1 plug, then found .462 and set timing pointer to match that mark. Synced the carbs. My issue is this: I pull the plugs and ground them, hook up remote starter and timing light. All plugs have spark. When i use the timing light, it appears to be at 0 degrees to maybe 3-4 ATDC. I adjust the max advance screw, however the timing doesn't advance. It stays right at 0, and I keep slowly turning the screw and nothing. Then it will jump to the .462 mark and beyond to no markings. No matter how slight I turn screw, it wont go anywhere between 0 and .462? I know I am supposed to have the correct timing meet the pointing mark, but it won't! It doesn't even get close. I would note that the timing light makes a "light" mark on the flywheel--like you would use on timing an I/O, and that moves when I adjust the max screw, and I can get that to the 20 BTDC mark on flywheel, but the 20 BTDC mark will not move anywhere close to the pointer on flywheel cover. What am I missing here? Please help me before I go crazy with this!!!! Thanks guys.

 

[Dukedog]

"inductive" timing light?... do you have tha timing arm pushed all tha way back against tha stop on tha block?

 

[ThomW]

Yeah Dukedog, it's an inductive timing light...nothing fancy. Yes. I have the throttle arm pressed all the way back against stop (at the max advance screw). I can start with that screw all the way in and move to all the way out and never get the correct markings on the flywheel to match up to the pointer. It stays at 0 through most of the adjustment and then jumps past the .462 mark to no marks. Do i need to have the throttle cable attached to the arm and in WOT (neutral of course)? Right now the cable is not attached, but I am moving the throttle arm/lever by hand and with the max advance screw.

I have read a few places about having to disconnect the idle stabilizer before setting the timing, however, my motor has a control module, not a separate idle stabilizer. You cannot disconnect just the black.white wire that I have read are for idle stabilizer. Would that have any effect on this issue?

I really wanna have this fixed by the weekend. Its going to be 84 and sunny tomorrow!

 

[Dukedog]

right on tha "no separate idle/advance module" ona cdm motor.... easier with cables disconnected... are you usin' something (bungee cord best) ta hold arm against tha stop?.. not tryin' ta turn screw while crankin' are ya?.. sure ya checked for very free and complete range of movement of trigger?.. jus hard ta visualize ona computer!.....

 

[ThomW]

I did't have the arm strapped to the stop. Would that matter? I was holding it against stop with my hand. I'd say I would try a different timing light, but I just used it to time a Mercruiser 3.0 I/O and it worked like a charm. I tried turning screw without cranking and while cranking. Neither seemed to move the numbers showing on the flywheel anywhere close to pointer. What is wrong/happens when you turn screw while cranking? The trigger will move with the arm freely and has a complete range of motion. I would say it moves close to 3 inches, from front to back?

I know that the numbers are supposed to move on the flywheel to line up with pointer, but what is the "white" mark that the timing light puts on the flywheel indicative of? I am talking about the white mark that it shows on the flywheel that you would see on the 3.0 to time it, where there are no numbers on the flywheel and you try and get that mark to match the plate on bracket. I can see that on this flywheel and it will move while I turn the screw, but the numbers won't.

Also, a few times the numbers I would see would on the flywheel would change--it would be 0 the 10 then 0 then 10 as the light flashed each time. That was without me turning screw at all. What would cause that?

I really appreciate you helping with this. Hope we can figure it out here.

 

[Dukedog]

i don't understand tha"white mark" thing? is it "ON" tha flywheel or does tha timin' light "paint it" on tha flywheel?.. either way only thing to be concerned with is numbers on flywheel and pointer.. i use tha bungee deal to eliminate any "accidental" movement and free up a hand... jus seems ta be more accurate by adjusting screw then checkin' and so on...... jus for tha heck of it, have ya checked "idle timing"?.. something is outta whack for sure.. if that trigger moves in either direction timin' has ta change unless tha ecm is doin' something weird or light is not workin' as should.....

 

[ThomW]

Haha. Sorry to be confusing. I was referring to a mark the timing light "paints" onto the flywheel. Like I said, that moves when I adjust max screw.

When I check idle timing its about 3-4 ATDC. Then that moves to maybe 7-10 BTDC when I move throttle lever to try and set max timing, but wont get to the 20 or 24 BTDC i need.

That's what I was thinking. There is a ton of movement with the trigger that does not move the timing marks at all! That cannot be correct. then, like I said it will be at 7-10 BTDC and jump to .462 mark and beyond, no matter how fine I try adjusting the screw. Just skips right over the entire 10-30 timing marks!

Mine is a Merc 200 carbed model. I know it has the control module, but that's not the same as the electronic control module, is it? Any ideas on what I should try and/or check to eliminate possibilities when I get home tonight?

 

[Dukedog]

they are tha same.. jus something i heard it called when they first came out on tha 2000..... think when first hit they were called 'lectronic control module (ecm) but lotsa folks got it confused with tha ecu when dealin' with tha efi's plus sayin' tha carb motors didn't have an ECM so tha 'lectronic (E) part got dropped and all tha dudes were happy again...... thats tha story i got anyway.

 

[ThomW]

Well I just ran up to Harbor Freight and bought a new timing light for $25 to see if maybe something is wacky with my old one. She is probably 15-20 years old. I'll head out tonight and try the timing again. I'll use a bungee cord this time and see what happens. Just to be clear, I don't have to disconnect anything like the idle stabilizer on my motor, right?

The upper part of throttle lever arm is to be pressed against stop, but I don't need the lower part (where Idle stop screw is located) pressed forward like it was in full gear, correct? moving the top section will--or should--advance timing fully? Thanks again.

 

[Dukedog]

lemme know.. i'll talk ta coupla guys that know tha cdm motors lots better than i do ina day or two...... yep, jus tha upper part against tha stop is fine....

 

[ThomW]

Thanks man. Appreciate it. Hoping I can get her out on the lake this weekend...but I guess we will see.

 

[Dukedog]

jus talked ta one of 'em.. he suggested swapin' a coupla cdms with number 1 ta eliminate cdm as culprit but felt like its gonna be tha control module without not being able ta test it....

 

[ThomW]

Could the CDM be bad if I am getting good spark on all 6 plugs?

 

[Dukedog]

he said probably not but has seen some very strange things go on with tha "electronic motor"............

 

[ThomW]

Hmmm....What symptoms would a failing or bad stator cause? I know it wouldn't charge battery, but what else might happen? I probably wouldn't have good spark on all 6 if the stator was bad, right? I really can't understand what the hell is going on here.

 

[Dukedog]

this is straight outta tha book.....

"[FONT=&quot]1) Intermittent, weak or no spark output at 2 spark plugs (one plug from each bank of three cylinders) usually is caused by a bad TRIGGER. 2) A SWITCH BOX can also cause 2 cylinders (1 each bank) to lose spark. 3) Intermittent, weak or no spark output at 3 spark plugs (a complete bank of 3 cylinders) usually is caused by a bad STATOR or SWITCH BOX. 4) An IDLE STABILIZER/ADVANCE MODULE can also cause 3 cylinders on 1 bank to lose spark. 5) Intermittent, weak or no spark output at any one spark plug (single cylinder) usually is a bad COIL or SWITCH BOX. 6) Loss of spark to 1 cylinder could also be caused by a loose or broken PRIMARY LEAD between the switch box and ignition coil or a broken or loose GROUND lead between the ignition coil and engine ground. [/FONT]

 

[ThomW]

Such large font....my goodness. So, I am guessing my stator is fine since I get good spark at 7/16 in open air on all 6 plugs. Hmmm.....

 

[Dukedog]

forgot ta change it when i copied and paste............ for a switch box motor so take it with a grain a salt....

 

[Dukedog]

Such large font....my goodness. So, I am guessing my stator is fine since I get good spark at 7/16 in open air on all 6 plugs. Hmmm.....

pretty much tells ya tha stator and cdm's are ok.......

 

[ThomW]

What is really strange is the boat was idling great. it just wasn't taking the throttle to well, but after some playing and pumping the carbs, it would run up to about 4000 rpm's without an issue. That led me to think carbs were an issue. So I removed and rebuilt/cleaned. I haven't taken it back out yet, as I wanted to ensure timing was good, and wasn't contributing to the issues I experienced. For all I know, the timing may be fine, but I wanna check before going back out. I just cant get a good reading or get it to adjust when I try! Grrrr....