2001 Mercury 200xl Timing

[dsiekman]

Pretty much since I got this "new to me" 01 200xl I have had issues. End of season two years ago it was hard to start and ran rough. I assumed it was carbs so I rebuilt them. Better but not great. It would still begin to stumble around 2500-3000 rpms and was still hard to start. It also wanted to idle high. 1200rpms or so. I messed with the idle speed adjustment but never got it much under 1,000. I did a bunch of work on it last year (new tstats, head gaskets, water pump) but for other reasons never made it to the water. Fast forward to this year.

Took a bit to get running but ran pretty well on muffs. Decided to drop it in. Coming back to my slip I had the same stumble around 2500 so I pulled the cowling. I took a video so I could review later. What I saw during video review was a little scary. There was significant arcing coming from under the flywheel. I pulled the flywheel and replaced the stator. Now it starts easier and does not seem to put out fireworks, but wants to idle at around 1800 rpms. Perhaps from me screwing around with the idle speed a couple years ago?

So here are the questions:

1. I do not currently have a timing gun or dial indicator with extension and spark plug hole adapter. Do I really need to verify TDC, or can I assume the indicator needle is accurate? Note, the shaft on this motor is fluted, so there is only one way to put the flywheel on and it has no key to shear off.

2. If the stator was the issue and I was messing with the idle speed, could that adjustment be causing my current high idle?

3. For every positive review on a timing gun, I read four that claim it is junk. Does anyone have one they like? I really didn't want to spend $100 or more on a tool I won't use more than once a decade, but I also don't want to buy junk.

4. Since I know that I only messed with the idle speed (which I believe is tied to the timing), do I really need to verify the timing or can I just back off the idle speed adjustment via the tach and take it for a run?

Thanks in advance!

 

[Texasmark]

Digital electronics is a wonderful thing. ebay has lots of things at good prices. Iboats has online manuals you can rent by the day provided as fast as you pay with your CC. I'd say that would answer your questions pretty fast at a very reasonable price.

 

[Dukedog]

do you an oem manual?.. if not send me an email addy and i'll send ya one in pdf........ all idle speed/rpm is done with idle timin' screw...

"1. I do not currently have a timing gun or dial indicator with extension and spark plug hole adapter. Do I really need to verify TDC, or can I assume the indicator needle is accurate? "......

there is "that" word, assume... your choice but................................................................

 

[dsiekman]

That's fair. I have a sealoc manual which describes the procedure. It was just that the way they describe the procedure and tolerances is more along the lines of what I would expect to find if I were fine tuning a race boat, not keeping my old fishing boat running.

 

[dsiekman]

That said, does anyone know what size the spark plug hole is so I can get a top dead center finder?

 

[Faztbullet]

What was rubbing causing arcing??? Was magnets cracked?

 

[dsiekman]

Nothing appeared to be rubbing, so I assume one of the coils or one of the leads was shot and grounding out. My assumption is the high speed coil since it seemed to be having issues starting around 2500-3000 rpm. To be honest, I have not looked closely at the old stator to see if I can find the issue.

 

[dsiekman]

Here’s a link to the video. You’ll see what I’m talking about towards the end.

https://youtu.be/mQdg9oOVty8

 

[Chris1956]

An easy search showed timing lights for less than $30. Blowing up your motor costs more that that.

You can verify timing pointer with a small steel ruler. Set the #1 piston to TDC using a screwdriver. Measure from cylinder head to piston top.

Now add .464 inches to that measurement and then back off the piston until it reads .464 BTDC. Set the timing pointer to that position.

 

[dsiekman]

Thanks, guys. I have an Innova Pro timing light on the way as well as a "top dead center tool" which essentially looks like a bolt and a threaded sleeve. Getting down to the thousandths of an inch is pretty precise. I can get my digital caliper to go there, but not sure my eyes or marking device will be so accurate.

 

[dsiekman]

This may be a really dumb question, but follow me for a second. TDC should be easy enough to find, right? It is the highest point of travel of the piston. The firing point is a spec'd distance before reaching TDC. That said, the distance between those two points does not change. Also, the distance between the marks on the flywheel do not change. The movement of the piston and flywheel are a fixed ratio. If something has worn enough for them to be off, you have bigger issues.

That said, why aren't there two indicators, one fixed to align the flywheel and piston to TDC and the other adjustable to check or adjust the timing? You could simply line up TDC which cannot change, then shoot your timing light at the second indicator for BTDC where the spark should actually occur to get your reading. That seems like a far less convoluted way to do this. Or maybe I'm overthinking it.

 

[Dukedog]

lotta folks have been thru this "over thinkin'" process soooooo.. merc has been at this for a very long time so would it not be fair ta say they know what they are talkin' about.. short cuts have been tried before with nothin' about tha efforts being easier and/or beneficial.. jus sayin'.. think you will find tha seloc ta be a joke compared ta oem in most cases.. way to generic....... jmo.

 

[Texasmark]

That said, does anyone know what size the spark plug hole is so I can get a top dead center finder?

You can stick a wooden dowel in the hole and carefully find TDC. Come into it in the CW direction looking down on the flywheel after you find the max travel of the piston. Or just line up the marks on the flywheel and the reference point....if you are so fortunate to have such, again coming in from CW direction........that's how I would do it....not necessarily agreeable to everyone.

 

[dsiekman]

Thanks, guys.

Yes, I agree, the Sealoc manual is pretty useless and a hard to use due to so many engines being covered by the same book. Dukedog, I'll take you up on your offer, thanks!

 

[Faztbullet]

You cannot find TDC with screwdriver or stick!!! You need a dial indicator as when piston reaches TDC the crank can go several degrees BTDC or ATDC without moving piston. The screwdriver/stick only works to see if you have a sheared key...

 

[dsiekman]

I have a dial indicator. From looking around online it looks like I need to make an adapter out of an old plug

 

[Texasmark]

You cannot find TDC with screwdriver or stick!!! You need a dial indicator as when piston reaches TDC the crank can go several degrees BTDC or ATDC without moving piston. The screwdriver/stick only works to see if you have a sheared key...

Yes sir! Grin

 

[dsiekman]

So....462 was dead on. Tried to do the rest of the link and sync. Oil injection mark was way off - that couldn’t have helped. I couldn’t get the light to fire with plugs out so I put it all back together and started it (in the water). Idle in neutral was about 1800. Backed it down to around 1200. Timing was at 0 degrees. Wasn’t running smooth. Adjusted the idle pickup timing (middle screw) to about 5 degrees. It sounded really happy but rpms back up to around 1800. Couldn’t get them lower. As I sat there scratching my head it started picking up rpms on its own. I shut it off at about 2800. Sounded like it was running away.