Need help--older Mariner 40EL rough idle with bad shaking in gear

[Tall Tiller]

I'm no mekaneck, but just my own thoughts... It's a Short Shaft issue.

 

[cyclops2]

Original post was in 2021..........DUUUHHH

 

[LDUBS]

Original post was in 2021..........DUUUHHH

So what. Nothing wrong with resurrecting an old post.

 

[SAABologist]

I'm no mekaneck, but just my own thoughts... It's a Short Shaft issue.

I have a mariner 40 EL. I deleted the automatic oiling machine and use pre-mix. I think that 50:1 is a bit oily and the plugs do foul in time. If you keep the carbs clean and always have new plugs handy (5 mins to change both) it runs like a workhorse. It's the easiest motor to work on I've seen. I gather from the thread that the original poster had a CDI problem. Now I know what to check if mine starts running badly and plugs is not the fix.

 

[cyclops2]

A study of engine problems came up with a surprising fact. Most problems are electrical.

 

[thill]

Original post was in 2021..........DUUUHHH

Oops... Must have been up late reading the threads.
Sorry, but maybe it will help someone else.

 

[SAABologist]

A study of engine problems came up with a surprising fact. Most problems are electrical.

I guess so! Mine would not start the other day and I think it was an ancient non-marine toggle switch that had replaced the original kill switch. I replaced it with a good kill switch and now it's been fine. Happy boating,

 

[thill]

Bad kill switches and bad key switches are notorious, as well as corrosion on connectors. Have had a number of customers come to me with an engine they thought was done, and when I unplugged their wiring harness and I plugged in my test harness, VROOM! Started and ran just fine.

I often tell customers who call me to unplug the control and jump the solenoid. If suddenly they start getting spark, they have narrowed down the problem. It's not the motor. That works a good percentage of the time.

 

[SAABologist]

Bad kill switches and bad key switches are notorious, as well as corrosion on connectors. Have had a number of customers come to me with an engine they thought was done, and when I unplugged their wiring harness and I plugged in my test harness, VROOM! Started and ran just fine.

I often tell customers who call me to unplug the control and jump the solenoid. If suddenly they start getting spark, they have narrowed down the problem. It's not the motor. That works a good percentage of the time.

Thanks for this comment. Pull starting this motor, even cold, is not difficult. How do I bypass the switches so I can pull-start it if necessary? Thanks!

 

[thill]

Just pull the plug at the end of the control cable. If it still won't start, unplug the kill switch on the tiller, if it has one.

 

[SAABologist]

Just pull the plug at the end of the control cable. If it still won't start, unplug the kill switch on the tiller, if it has one.

Mine does not have a tiller. Please correct me if I am wrong here---
When you say unplug end of control cable, that would mean disconnecting the wire harness inside the motor?
That is great to know in case ignition switches fail.
Thanks again,

 

[thill]

Yes, unplug the cable that comes from the key switch. Just remember that if you need to kill the engine, plug it back in. Sometimes it will start when you didn't expect it to.

 

[SAABologist]

Yes, unplug the cable that comes from the key switch. Just remember that if you need to kill the engine, plug it back in. Sometimes it will start when you didn't expect it to.

Thanks, It is starting instantly and running great now, so I will do some trials with this as a sort of emergency training. I think it dies quickly if I pull the choke.