is it my power packs or stator

[rush1]

I have a 98 mercury xri 150. The three cylinders on the left side of the engine stopped getting spark suddenly. I was told that it was the power pack and if i flipped them the opposite side would run. I tried it just to check and now it wont crank no matter how i put them. Im really clueless about outboards and I dont want to start replacing things that dont need replacing. I was also told that it may be a stator issue. Any help would be greatly appreciated.

 

[jigmister]

Re: is it my power packs or stator

Let me start by saying I am just learning to work on my outboard. Been down the road your on now not too long ago.
with that in mind I think if you are going to do all your own repairs first thing to do is get the manual for the motor. Get a vom if you dont have one and a DVA adapter.
Check out CDI website and read up on your motor.
You will get it fixed if you take your time.
Other wise your just randomly changing parts until you guess the right one.
All cylinders on one bank going out is a typical symtom of a bad switch box.
I would start out with a dva test of the stator.

you say power packs. I think your talking about the switch boxes

 

[Sunfish12]

Re: is it my power packs or stator

Are you saying the flywheel won't turn(engine won't crank)? Switching the boxes won't stop it from cranking, you now have seperate problems.

 

[j_martin]

Re: is it my power packs or stator

Are you saying the flywheel won't turn(engine won't crank)? Switching the boxes won't stop it from cranking, you now have seperate problems.

I think rush probably means fire, instead of crank. Most newbies mix it up and don't realize how important it is to choose words that describe exactly what is happening.

Anyway, back to the OP's problem. There's a remote chance that something took out the first switchbox (Mercury term for power pack) and the same fault took out the second one when you swapped them.

More likely, however, is a common fault that got a bit worse, such as low output from the stator, or a resistive or intermittent gound fault on the kill circuit. Another common fault is slow cranking speed. It needs to spin over briskly for the stator to put out enough to the switchboxes to make a spark.

At this time, double check all your connections to the engine wiring diagram before you proceed. If you don't have a diagram, don't proceed till you get one.

Then, try disconnecting the kill wires from both switchboxes and try to start it. If it starts the problem is in the kill switch, ignition switch, or wiring. Choke out or disconnect the fuel from the engine to kill it.

After that, you need a DVA, and maybe a spark tester to continue.

hope it helps
John

 

[rush1]

Re: is it my power packs or stator

The engine turns over just fine. Sounds like I have a few lessons to learn.

 

[j_martin]

Re: is it my power packs or stator

The engine turns over just fine. Sounds like I have a few lessons to learn.

If yer halfway's bright, you have it made. This engine is about 1/4 as complicated as an automobile engine.

 

[heroforlife911]

Re: is it my power packs or stator

Just a little note ... and someone can advise if I'm wrong ...

I was told by several guys at a few different Mercury shops that if you lose one switch box and it needs to be replaced then you should replace BOTH of them. Something to do with the way new switch boxes are manufactured, yes it will run after you replace just the bad one but its only a matter of time before it trips up and creates issues with the older non-replaced one...

It might not be totally correct mechanically and based off some type of sales stunt designed to push product and services out the door, but I decided to replace both of them while I was at it. Its a little extra coin but I figured that the second one would soon follow the first one anyways.

Shop manual is a must and most of them include wire diagrams ... As far as the trouble shooting to determine if its the power switch or stator, I would do some more research. Good luck!

 

[j_martin]

Re: is it my power packs or stator

There's some differences between the packs. The big item I see is that often the failure is in the bias circuit, which is jumpered between the switchboxes. If they vary, you could have different timing delays between the switchboxes, perhaps enough to do major engine damage.

It's good to replace them in pairs, or at least use the same revision number and make sure the bias circuits match. (ohms to ground)

Another quick check would be to install different switchboxes, and at idle disconnect the bias jumper and read bias to ground on each switchbox. They should be close to each other.

hope it helps
John