Testing coil packs

[BillC1996]

I have a 2002 Merc 200 XRi (carb) sn 0t445604 that started experiencing some issues last year. The engine starts great, idles, and runs smoothly, but cannot get out of the hole.
Prior to this issue the boat ran awesome. I was running 5700 Rs, and no problems getting on plane at all, even with three adults and a full tank of fuel. The day this started, the I ran up lake with no issues, but when I was ready to head home the engine was hard starting. It did eventually start and bogged a bit as it got on plane. Once it was running, it ran fine, but then after about 10 minutes, it completely shut down - no warning horns, nothing. I started the boat back up, and the engine started immediately, but from that point couldn't get out of its own way. It is running about 5K Rs now at WOT.
I have replaced all the fuel lines and filters, thinking that I may have had some type of obstruction, but no change. The in line filter was clear, and I blew fuel straight through it with no issues, but replaced it anyway. Primer bulb is good and I just rebuilt the fuel pump, with no change. I'm thinking now it may be a spark (or lack of) issue. What is the best way to diagnose and test the coil packs, and are there any videos posted that show the process? Thanks, Bill

 

[Texasmark]

CDI corporation is supposed to have a help site for folks having problems with their ignition modules. Might google CDI and follow the map.

 

[schematic]

check each cyl. for spark while cranking. If no spark at a cyl., swap coil with others and see if problem follows. Be sure all ground wires at coils are secure.

 

[BillC1996]

check each cyl. for spark while cranking. If no spark at a cyl., swap coil with others and see if problem follows. Be sure all ground wires at coils are secure.

That's what I was looking for. Thanks!

 

[enginepower]

I had a friend with this problem. He rebuilt carbs and it ran great for a while but one the the seats wasn't tightened and it started backing off and shut the fuel off to one of the carbs (which kills 2 cylinders) and you can't tell on the hose because there isn't any load.

 

[Dbnail]

check each cyl. for spark while cranking. If no spark at a cyl., swap coil with others and see if problem follows. Be sure all ground wires at coils are secure.

Spot on!

 

[BillC1996]

Update: I pulled each plug and had my kid crank the engine while I held the spark plug near the engine block. Each plug had spark and the coil was strong enough to jump a gap of about 5 mm. The #1 plug had some oil on the threads so I was suspicious of it. Luckily, my kid has a Nitro with a 150 Merc - it uses the same coils - so I pulled one of his and put it on my #1. A quick trip to the lake this afternoon and the boat jumped up on plane and ran better than it has ever run. I had to back down on the throttle, as I was actually running a little too close to 6k on the screw. This makes me believe that the coil was weak for a long time, as I usually ran 5600 RPMs at WOT, and it finally went TU last fall. I have a new coil on order and may even put the new one on the kid's boat when it gets here...

 

[Faztbullet]

A 200Xri is a fuel injected motor and that is a CDM module. You need to test the CDM you removed on your sons boat as its possibly OK. CDM modules do fail but usually it a different module that causes the one acting up to look defective. If this is the case then the one you swapped will start acting up again as defective one will start effecting it.