87 Merc. 9.9 No Spark

[David M. Johnson]

Hello everyone. I am new to this board. I've browsed around and it looks like a good place to hang out.<br /><br />I have a 9.9 Merc SN# 0B204438 that has no spark. I bought the engine new to use in PA Fish Commission controlled lakes. I've hardly used it since I bought it, has less than 15 hours on it. It was running fine and I let my younger brother take the boat on vacation a few years back. When he got home, he told me that all the engine would do was idle and would stall if any throttle was applied. <br /><br />I hooked it up to my engine flusher / hose and couldn't get it to fire at all. My hunch is that one of his boy's hooked up the battery cables backwards (and won't admit it) but, oh well, stuff happens.<br /><br />What I'd like to know is if it is possible to test the ignitions components to know what to replace. Any ideas or suggestions would be greatly appreciated.

 

[krmarine]

Re: 87 Merc. 9.9 No Spark

First thing to do is check your spark. pull your spark plugs, lay them on the cylinder head (ground) and pull it over. you may have to have somebody looking at the plugs as you pull it over. If there is spark, it is most likley a fuel problem. If there is no spark, the first place to check is the kill switch. Follow the kill switch wires to where they connect. one wire will be ground and the other will be plugged into another wire.disconnect the plugedin wirenot the ground and test. if you still have no spark, get the service manual and a good digital multimeter to test further. Have fun

 

[David M. Johnson]

Re: 87 Merc. 9.9 No Spark

Thanks Dan for your reply. The engine has remote controls so I guess I'll have to split the halves and check the wire color. Didn't think that it may have a bad kill switch. I checked prices online for the ignition components. My gut tells me it is the switchbox. Best price I found on it is $130 so I didn't want to get it unless I was sure that it was the problem.

 

[David M. Johnson]

Re: 87 Merc. 9.9 No Spark

BUMP.<br />Still looking for suggestions. <br /><br />Are there anyone on here for Merc that can tell me or steer me to where I can find info on how to test the ignition components on my engine?

 

[David M. Johnson]

Re: 87 Merc. 9.9 No Spark

I've messed with this some more trying to figure out what was wrong. I hooked up the hose to it and tried starting and it started but would only idle. Any attempt at applying throttle would shut it down. I let it idle for about 15 minutes. Shut it down and it wouldn't start again. I pulled the plugs, clamped the base of them into a set of jumper cables so I could clamp the other end to a bare ground and all I was getting was one spark on the top cylinder. Let it set a while and I'd get another spark. The spark was strong when it happened.<br /><br />Here's what I've found so far. I removed the ignition parts from the side of the engine for close inspection. I found a crack in one of the coils. I disconnected the cracked coil but the symptoms remained the same. Question - could a cracked coil have damaged the switchbox assy? Can the switchbox assy be tested to see if it is bad?<br /><br />I've pulled the flywheel to get a close look at the stator and trigger. Nothing appears to have been hot. Keep in mind that although this engine is old, it only has between 10 and 15 hours on it. It looks brand new underneath the cover. I tested the ignition switch and kill switch with an ohm meter and they test ok.

 

[David M. Johnson]

Re: 87 Merc. 9.9 No Spark

Bump.