40 HP 1985 Mariner

[banchigu]

Hello Folks

I have a 40 HP 1985 Mariner engine that has been great little motor for over 20 years. A few weeks ago my ignition switch crapped out on me and when I managed to get it going the boat began to sputter or miss when I powered up. So I got to land safely and changed the ignition switch with the correct one and while the switch is working fine the sputtering did not stop. I cleaned the carbs, changed plugs and checked all the vacuum and anything else I could think of but it still sputters. It misses or sputters at 1/3 throttle and once it gets to full or near full it runs fine. It still reached the same speed of 27 mph like always and my fuel consumption has not suffered. Could the bad switch have hurt my stator or coil?

A Million Thanks
-a

 

[Laddies]

Re: 40 HP 1985 Mariner

If the bad switch put 12 volts to the ign. system it probably damaged it, you will need to test the components It also wouldn't hurt to make sure there is no voltage at the black yellow switchbox wire

 

[banchigu]

Re: 40 HP 1985 Mariner

Laddies one thing I wanted to mention was that if I rev it up w/o engaging the prop drive it does not miss. Also what are the parts of the ignition system are they the wire and battery harnesses that are connected to the stator or are you talking about the coil and module?

 

[Laddies]

Re: 40 HP 1985 Mariner

Free revving a engine don't tell you anything as you can tell from this experince and can damage your engine. I am talking about testing the complete ign system, but I think you have a 4 cyl 40HP engine, I can be of more help once I know the engine we are working on

 

[banchigu]

Re: 40 HP 1985 Mariner

Okay sorry Laddie...

It is a Mariner 40 hp 2 cylinder 2 stroke 1985 MFG. I hear you on the rev damage but I did not do it in excess and I agree it can damage the engine. It is just driving me crazy because it idles and really well and like I said once it is over that 1/3 throttle is runs perfectly.

Again thank you so much, also do you know where can I find an engine diagram for this engine online?

A million thanks
-a

 

[HondaPower]

Re: 40 HP 1985 Mariner

Go to: mercurypartsexpress.com, type in your serial number and it will give you a parts diagrams as well as part name, number, and pricing. I saved all the diagrams from the site before I found my manual. It was a major help at that time. Good luck.

 

[Laddies]

Re: 40 HP 1985 Mariner

First I must tell you I thought your engine was a 4 Cly 40 built by mercury, sorry to say we don't work on the Japanese engines but I a book that explains the principles of their systems. It looks to me that they use 1 energizer coil, a trigger coil and ignition box on the later 40HP 2 cyl engines, if you can find the specs for the system it should be easy to test with a OHM meter. If your system is the one I descibed the I would suspect either the energizer coil under the flywheel is not producing enough voltage at low speed to fire the system or the coil is breaking down on one side. I wish I could be more help but simply have no experince on that system.

 

[banchigu]

Re: 40 HP 1985 Mariner

No need to apologize, however, you did help me a great deal in identifying the parts involved and where to begin. A million thanks to you and I will keep you posted.