LZ
08.06.2021 7:02:06
Although i didn't have the plugs gapped properly i did take out the motor earlier this week and no change. [links]
See full version: I think my outboard was running on one cylinder
Although i didn't have the plugs gapped properly i did take out the motor earlier this week and no change. [links]
You replaced a couple out of a half-dozen ignition components, so there's still a few things there that could be robbing you of spark in one cylinder.
Now i changed the plugs cause both were just black and when i started and idled my engine i pulled one plug cap and the motor idled down and was still running i put the cap back and pulled the other and the engine stopped. Now is this a correct test or am i completely off base here?
If it was how might it run?
I now have spark in both top and bottom after removing the wires and putting them back on both the plug and coil, if i wasnt clear in my above text more
Re: I think my outboard was running on one cylinder [links]
Kern is a life long boater who finds great happiness sitting at the helm of a boat running on the open water. When he's not running the boat, he's likely anchored up along the beach with his wife, kids and good friends enjoying a great day at the coast.
If you are having trouble with your boat motor, it may be losing compression. While any kind of mechanical problem can be frustrating, this goes doubly for something on your boat which is supposed to be this awesome piece of adventure and technology.
If you think your compression readings are low or they have a lot of variance between the different cylinders, here are some of the most common reasons why you would be getting readings like that. [links]
You’ll need to use the starter or the pull cord through around five flywheel revolutions. You’ll know you’ve done this enough because the compression gauge needle is going to stop going higher. here
Your engine you could be different depending on whether it is a two stroke or four stroke engine. There are additional features that can cause differences as well like a fuel injection motor or a engine that works with a computer setup. more
Generally speaking though, any reading below 90 PSI is going to indicate some kind of a problem. Most modern two-stroke outboard engines will produce readings somewhere between 90 and 110 PSI. Even this range has a lot of different variables that could change your readings based on how new your engine is and what kind of model it is. [links]
Re: Mercury Outboard (not firing)
You would take out the plug and plug wire to it then hold threaded part of the plug to bare metal of the block and see if it is firing. Consider new plugs every year or so anyway. I get zapped every time I hold a wire so screw that. Easy to get a spark tester for $5 at autozone then you can test the strength of it as well, and should jump half inch or so at idle. Sounds like a dead cylinder or two. Check plugs, if some or one is wet after running then no fire there and check ignition. If dry plug check for gas, if multiple carbs try squirting a little gas in each of them while running and see if it picks up rpm to locate problem & clean carbs. recommend getting "muffs" to run motor on hose on land. Do not overrev it, best to keep out of gear. Much easier to work on this way and it sounds cool(to some). Check all wire connections, fuel filters, etc. too. I had a pump bulb go bad and restrict fuel, but then it dies when you gas it. I tested compression by warming it, remove all plugs then do each hole on starter about 3-5 seconds you should get highest reading. If old you can squirt a small amount of oil in there and see if it gets better-a sign of wear on the piston rings. Good luck and let us know.
Re: Mercury Outboard (not firing) [links]
I would check the firing order first to make sure everything is right, that thing should run like new. Check the plugs first for some difference between them. Maybe pull wires one at a time to locate a bad cylinder, the one that does not change rpm.<br /><br />And make sure that hollow sound is not from no water in there to be on the safe side. here
Hi,<br />I am having the same problem on my Merc 200 2.4 I just had it rebuilt, compression,spark,switch boxes,stator,timer base,fuel pump,carburators all check OK. No power out of the hole then max's out at 4500 and sounds hollow as if its restricted somewhere? more
Sho,<br /> I have a flush kit, I have been running it out of the water (it does sound good).<br /><br /> I got some b12 and cleaned the carbs. I tried the spark test, no luck (no spark), but the plugs are hot after running, they are new and slightly fouled, like they are running, except the middle two are half fouled. I am going to get a spark tester Friday and probably a compression gauge too.<br /><br />I will let you know how it works out.<br /><br />Thanks,<br /><br />Joe [links]
I have tried a new fuel line from the tank to the engine with no increase in RPM so that will eliminate a constriction occur as a result of me putting all the lines through a single tube. [links]
Since I have eliminated the CDI (whew)it could be something really simple BUT what? more
I agree something fried the coil but am not sure what.
Thanks for that one JB123
I am now looking at getting a used CDI to see if it helps, if it doesn't I can always re-sell it.
Hi All
I took off the upper carbs and #2 was just loaded with crap, like huge. Possibly it got jossled around during shipping.