88 Mercury 45Hp Seems to be missing on 3 and 4

[Dizzi]

Ok Gents,

It has been a while since I have had a post with all of you. Here is my problem. This 45hp has been a bear to start after sitting this winter. I was convinced after doing a number of test on the ingition system that the switch box was bad. So, Today I decided to try jumping the triggers with the stator leads. I knew I had voltage at the red/white and blue/white wires and just took a jumper and touched the triders for a moment. What do you kow the darn thing started right up. It seems to be missing a bit. I used an ignition system light to test for spark and had spark on all 4cylinders. But this seems to be intermitent. I am wondering if the triggers are bad? I need to understand what provides the power to the triggers? Is it the Stator? Mine is the old Black one. I guess I need to know so I can buy a knew stator or a new switch box or both?

Any Help would be great.

Thanks

 

[mthieme]

Re: 88 Mercury 45Hp Seems to be missing on 3 and 4

This may or may not help...depends on the ignition system.

http://forums.iboats.com/showthread.php?t=286695

 

[Laddies]

Re: 88 Mercury 45Hp Seems to be missing on 3 and 4

Don't start buying parts intill you have tested the system, here's a test for it.

 

[Dizzi]

Re: 88 Mercury 45Hp Seems to be missing on 3 and 4

Thanks, I agree with not replacing things untill I have ran every test. I found your test sheet on an earlier post or yours and that is why I am where I am now. I finally got it running and I guess I need to do the running but miss firing test at higher RPM?

Will a clamp on Tach work with my DVM?

I still am curious as to why when I jumped the trigger terminals the darn engine started right up?

 

[Laddies]

Re: 88 Mercury 45Hp Seems to be missing on 3 and 4

I don't know what kind or tach you have but any induction type tach will show a bad cyl as it will either fluctuate or read low. I am not sure about the starting when jumping the trigger but think that it simple made the ign fire like a Jap one would and they fire with one cyl up and the other down, twice on each rotation and the Mercury sytem had 2 implses so it fired the same way.

 

[Dizzi]

Re: 88 Mercury 45Hp Seems to be missing on 3 and 4

Laddies,

Thanks for the help. I have performed all the electrical test and everthing looks within specs. I am still missing a bit but now my problem seems more related to fuel issues. Let me give you the history again to see what you think..

This boat sat for 6plus years. I pulled the carbs and cleaned them up and put on a set of new gaskets. I did not get the re-build kit only because it needed to be ordered and while I was waiting on it I gave cleaning everything up a try. I did have to replace the fuel tank and lines/bulb due to dry-rot. So I noticed today that when I pump the fuel bulb until it is firm I get fuel pouring from my carbs. I am conviced that the needle and seat may be in need of replacing but would like to try adjusting my floats. I do not have a manual for this engine. I did the online thing with iboats and it was not very much help in the electrical area. Do you have a procedure for this and or should I spend the money on the re-build kit? My back ground is automotive and I have access to all the tools a man could want. All I need is a guiding hand when it comes to this darn boat motor. I did do a compression test today and all four cylinders are at 127 to 130 PSI I am guessing that is good for this engine?

The questions I have:
1) should I nave replace the fuel lines / tank and bulb with OEM Mercury
parts only and is this part of my problem?
2) Do you have a procedure for setting the carb floats?
3) what about setting the timming? Can I use a timming light on the marks
What would the timming advance be set at on this beast?
4) should I just get the re-build kit for the carbs and start there?

Again thank you for helping with this I have no problems with four wheels but this boat stuff is greek to me.