No spark on 2 and 3

[chrislovessadie]

I have a Mercury 1986 or 87? 150 XR2 Black Max, Bought this boat in Nashville, Tn. last year, boat ran awesome and fast, you just had to push the throttle in slow until it warmed up. Got married and moved out to south west CO, and took boat out. Will start right off the bat, but as you engage the throttle it wants to bog down, I can only get it to go about 5 mph or it will stall out. Had high altitude jets installed, carb's rebuilt and cleaned, gas tank flushed, went from a 3 blade, 23 degree down to a four blade, 16 degree prop. still will not get up and go. just pulled main jets with motor running and had gas coming out. So I then pulled spark plug wires off one at a time starting with the upper left one(#2) and working my way down. #2 did not have spark and #3(right side, second from top) and did not change idle at all, the rest of them made it idle rough. I then took the coil pack from #2 and changed it with #4, (and 4 on 2) still no spark, Saw a online forum that said two wires don't fire until rpm's are up any one know if that's true? Also yesterday, on lake when trying new prop, it will die and sometimes I will have to use the fuel primer bulb to get it to start up again. But run the motor with muffs and it seemed to rev up nice, starts first time. Just cant take a load when engaged , Wondering if anyone on here had any ideas of what it might be? Thanks!

 

[hkeiner]

Re: No spark on 2 and 3

I couldn't quite follow what you did to troubleshoot so far, but the below linked guide may help.

http://dolphinmarineservice.homestead.com/Ign5.html

 

[j_martin]

Re: No spark on 2 and 3

I couldn't quite follow what you did to troubleshoot so far, but the below linked guide may help.

http://dolphinmarineservice.homestead.com/Ign5.html

Revving under no load means that at least 1 cylinder is firing. Other than that, it tells you very little.

Obviously you're missing fire on a couple of cylinders. You need a DVA meter to determine for sure if you even have an electrical problem. It could be something else like water intrusion, low compression, etc.

Before you get real involved in troubleshooting, you should do a compression test. If compression is bad, there is no "tune" item that will fix it. Once there, then test, repair, and verify ignition. Then go after the fuel.

Systematic diagnosis is the fastest, and least expensive route to a repair.

hope it helps
John

 

[Faztbullet]

Re: No spark on 2 and 3

Are you sure its #2 & #3?? The cylinders are laid out as so:

2 1
4 3
6 5
If you checked it like:
1 4
2 5
3 6
you have a pack/s bad....

 

[chrislovessadie]

Re: No spark on 2 and 3

Thanks for your replies, how do I test with a DVA meter? or test compression? do they sell the tools at parts stores? Thanks
Also I Checked spark in order from top left,down then up to top right and down. is it true that I should have spark on all? or just when rpm's are up as someone told me?
I will check compression tomorrow

 

[hkeiner]

Re: No spark on 2 and 3

As a newbie, you should get a Mercury shop manual for your motor. It will provide you with a lot of information that you are unlikey to ask or obtain just by posting questions on this forum, especially when it comes to testing ignition systems. Also, you risk damaging parts (resulting in more expensive fixes) if you don't know what you are doing. This is a great forum for asking specific questions on troublesome problems, but it does not substitute for what you would learn from a manual. Just a suggestion...

 

[chrislovessadie]

Re: No spark on 2 and 3

I think you are right! I will get a Mercury shop manual this week, as it will get over my head. someone told me my trigger was bad. we will see. Thanks

 

[hkeiner]

Re: No spark on 2 and 3

someone told me my trigger was bad

The "someone" could be right if he performed systematic troubleshooting that definitively pointed to the trigger as the problem. If it is was only an educated guess, you may be replacing a part unnecessarily. The nice thing about ignition failures that are NOT intermittant, it that it is usually easy to pinpoint the problem by systematic troubleshooting. If your ignition problem were intermittant, then that's where the forum experts can really help a lot.

 

[chrislovessadie]

Re: No spark on 2 and 3

What should the trigger and stator readings be for this? have someone that knows how to use meter coming over to help this weekend thanks btw compression checked out good on all!

 

[hkeiner]

Re: No spark on 2 and 3

Shown below are the specs for my 1996 150hp motor, as an example. These same specs may apply to your motor or they may not. I do not know. That is why getting a manual for your exact motor is recommended. A manual will also describe exactly how to do the varous tests in addition to the appropriate meter readings.

 

[chrislovessadie]

Re: No spark on 2 and 3

where is the best spot to get a manual?

 

[hkeiner]

Re: No spark on 2 and 3

I got mine on ebay. You might try ebay, search the web, or contact a local Mercury Marine dealer. Others on this forum may be able to provide you a direct link to an on-line source.