1979 85hp Johnson Seahorse Spark Trouble

chadbrew

Cadet
Joined
Jul 12, 2015
Messages
22
1979 Seahorse 85hp. Runs very rough at idle (sputters) and wot is very low rpms and sounds like running on one cylinder. Checked compression and all 115 -120. Cleaned carbs and put in kits. New plugs getting wet. Bought a spark gap tester and was getting marginal spark on starboard side and lightning bolts jumping great distance on port side. All coils measure same ohms. Swapped power packs and now port side has marginal spark and starboard has nothing. Swapped packs back and marginal on starboard again and now very weak on port. Scratching my head. ??? I'm not sure what could be causing spark to be intermittent?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,047
Slow cranking will mean marginal spark on these motors.---------You may want to inspect the starter motor amd charge the battery.---------Note ---many folks are confused by this slow cranking / poor spark concept.-----Not sure why that is.
 

Bosunsmate

Admiral
Joined
Apr 7, 2012
Messages
6,129
Slow cranking will mean marginal spark on these motors.---------You may want to inspect the starter motor amd charge the battery.---------Note ---many folks are confused by this slow cranking / poor spark concept.-----Not sure why that is.
Quite simple really, its because not everyone was born knowing that.:rockon:

Chadbrew you will find out how to check your lack of spark in here
http://issuu.com/cdielectronics/docs/troubleshootingguide
 

chadbrew

Cadet
Joined
Jul 12, 2015
Messages
22
I'm familiar with the slow engine turn over equating to less spark. The battery isn't driving me crazy. I actually took the starter apart and cleaned it the other day so it would turn over faster. The engine starts. It will stay running. It smokes a decent amount and I'm not sure if that is normal. It also just sounds like it is constantly missing or sputtering and won't hit high rpms. Under a load (on the lake) it will die at low rpms. There is a problem somewhere and I'm trying to run it down. I'm going to do more spark testing when it gets dark so I can see it better.

Thank you for the link to the ignition testing. It should provide me with a few hours of testing fun. :)
 

Bosunsmate

Admiral
Joined
Apr 7, 2012
Messages
6,129
No worries, i dont have a DVA which is mentioned in that link, i just use a digital multimeter which cost me about $8 and I do the resistance tests that they talk about. If something has gone wrong with a part i normally find it by just checking the ohmn reading. ALso checking whether the wires have shorted to ground (cracked wire coating) with the multimeter can pick up the cause of faults too
 

Bosunsmate

Admiral
Joined
Apr 7, 2012
Messages
6,129
Also when cleaning carbs on those every single tiny hole has to be checked to be clear with something like compressed carb cleaner or wd40. If the aerosol does not blow cleanly out the outlet of each passage and orifice/jet then that little blockage will cause the engine to tank. Sometimes it the tiniest passages which are blocked and make the engine run bad. The old fuel seems to gel up in them quicker.
Once they block up the engine will run backfire and run lean and hotter, the running lean and hotter is what can kill the whole motor, and all from just a tiny passage being blocked
 

chadbrew

Cadet
Joined
Jul 12, 2015
Messages
22
hehe I have a volt meter I'll use tomorrow. On the carbs, I've had them apart so many times now. I've used carb cleaner on them, put kits in them, used a sewing needle, and blew through all the holes with low pressure air compressor. I'm relatively comfortable with the carbs being clean.

I just checked in the dark and am getting real good spark on top cylinder both sides and zero spark on bottom cylinder both sides.
 

Bosunsmate

Admiral
Joined
Apr 7, 2012
Messages
6,129
cool, a lot of people think carb cleaning is just polishing them inside and out so thats good you dont need to disassemble them again.
You could try swapping your coils over and seeing if the problem follows them.
Might also be the stator, timing base or powerpack, so work to be done.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
CDI provides good information to test both the timer base and the stator-when the engine is cranking. I'd start your ignition troubleshooting with these two items first. You need to know if these two components are working normally before you consider condemning the power pack(s).
 

chadbrew

Cadet
Joined
Jul 12, 2015
Messages
22
Ok. I've ohm'd and ohm'd til I can't ohm any more. :) I can't find anything that is really off from what the manual says. I found the manual online and did all the checks I could. I checked the voltages as best I could with a peak volt meter. Most everything looks real good. What I did find were some bad connections from power pack to coil. When I moved the wires the engine picked up so I moved them enough to know the connectors aren't connecting good. Had a loose pin on one side and other side wire inside sealed connector seemed loose. I just cut out the connector and put new crimp connectors to get good contact. Now it is running much better but still has an issue. Sputters some and won't get up rpms very well. Smokes a lot (not sure if that is normal).

Pulled each plug off one at a time while running and each seems to make a difference, some more than others, but all are sparking. All cylinders are getting equally warm to touch. water coming out from engine is nice temp. I tried to upload a video so maybe someone will notice something but it keeps giving me an error.
 

chadbrew

Cadet
Joined
Jul 12, 2015
Messages
22
I'm running 50:1 gas mix. I'm putting a link to show the hiccups and rough acceleration. Boat will die at low speeds on the lake. Anyone?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,047
Run with a timing light on each cylinder.---Does not sound well to me .---Sounds like it is not running on all cylinders !!!
 

chadbrew

Cadet
Joined
Jul 12, 2015
Messages
22
Plugs have a little oil on them but other than that pretty good. I think it is an intermittent problem. I went to check volts to coil again and now no volts on starboard bank. Pull plug wires off one at a time and, yep, engine running on 2 port cylinders only. I knew that spark on bottom starboard cylinder wasn't as good as top but now there is nothing. I ordered 2 coils and a power pack for that side. We'll see what that does.
 

chadbrew

Cadet
Joined
Jul 12, 2015
Messages
22
Well, I've put on the new power pack and 2 coils for starboard side. Now as I pull off plug wires one at a time each one is firing. Good spark coming out of each plug wire. Also seems like quite a bit more suction on the bottom carb now. Guess that comes with now getting spark. As someone suggested it seems it might be a timing issue. I don't have a timing light but I guess I'll be getting one now. Any thoughts from watching this video?
 

oldboat1

Fleet Admiral
Joined
Apr 3, 2002
Messages
9,598
afraid it sounded better to me in the first video. would be better to try it in a barrel or trashcan with water to muffle some of the exhaust sound, and some back pressure to see if operation smooths out (or perhaps gets worse, if carb issues). could leave the muffs on when you dunk it. Had an 85, and sounded bad on muffs, of course, but nice and quiet in the water -- and could get a little better sense of whether it was running smoothly.
 

chadbrew

Cadet
Joined
Jul 12, 2015
Messages
22
I put new power packs and new coils on it on both sides. It ran much stronger but still had that horrible cough. After noticing that one carb was sucking air more than the other I focused on that. Sure enough, I'm kicking myself now. Turns out that among other problems, the carbs were not linked together properly. The adjustment was off causing one carb to open a bit more than the other. Fixed that and it runs a LOT smoother now. Can't wait to get it in the water to complete the link and sync procedure. You all were sooo much help. Thank you all. Will post again after I get it in the water to let you know if it is truly fixed.
 
Top