Can't Get a 1992 8HP Johnson Started Today That Started Yesterday

I bought a 1992 2 Stroke 8HP Johnson outboard the other day. It is a standard shaft rope start. The owner said it ran fine and it had been sitting in the garage for a couple years. We got some new fuel in the remote tank and it initially wouldn't start after the first 10 pulls or so because he didn't have the choke pulled out. After choking it the thing fired up after about 4 more pulls and revved up like you would expect but we only ran it for a few seconds because we only had a 5 gallon bucket and it wasn't deep enough to cover an additional small water intake that is above the cavitation plate and didn't want to chance it not drawing enough water. Satisfied with it running I took it home with me.

I built a stand for it and got in a clean trash can for a test tank and was going to give it a full once over and make sure it was pumping water and cooling properly and such before taking it out. The problem is I cannot for the life of me get it to show any signs of life even after troubleshooting it to death (short of breaking down the parts). I put new plugs in it, verified I'm getting a spark on them. The spark might not be as vigorous as I'd like, but that is probably due to me not being able to pull the rope very fast while leaning over looking for the spark. But it should be plenty to ignite fuel.

I've tried starting fluid through the carb, as well as in the cylinders with varying amounts, and not even the slightest indication of ignition. I've tried starting with throttle full, idle and everywhere in between. Choke on, off and in between. At this point my arms are shot and I'm not sure what to try next. This is not my first 2 stroke, but first outboard. I almost always find that even when something is wrong I can get a motor to at least sputter a little by placing some fuel or ether in the cylinder, and since it started yesterday without nearly the effort I've put in I'm thinking maybe I'm doing something wrong, or something got clogged in the carb between yesterday and today.

I would have to say the fuel delivery to the carb is not the problem, as there is a little fuel dripping from the carb after I prime the bulb. I don't know if that is normal though. The tank is vented (cap is just resting and not screwed in just to be sure). The original plugs were pretty oilly, but after since changing the plugs they seem to stay pretty dry despite all the starting I'm trying to do.

Anyone have any tips on how to get a general diagnosis on where the problem lies?

Thanks a lot of any suggestions you can offer.

Check your spark !!

Thanks for the reply. I'm pretty bummed, but worse than that I've torn or pulled something in each shoulder and I'm missing the skin between most of my fingers from trying to get this thing started for the last 5 hours. The original plugs were wet and I thought they looked close to fouled so I replaced them. The new plugs aren't getting wet at all it seems, but its tough to tell if they are getting any kind of wet since this is fresh gas (nothing burning) and clean metal, but definitely not flooding.

I did try putting fuel directly in the cylinders, nothing, not a blip of ignition. When I spark check though they both are sparking so I'm really baffled. I haven't compression checked, but just by feel there should be plenty of compression to at least run. Compression on both through the rope pull feels the same.

The only thing I can think is perhaps since sitting for the so long the fresh gas dissolved some solids a bit in the carb to clog something up? But that really doesn't explain why it won't even get me sign of any life when I directly insert fuel or ether into the cylinder. I've also turned the choke off and had full throttle (butterfly fully open) so I could spray ether straight down throat of the carb and it doesn't even give me a blip.

Just FYI, this the same model as the 5 - 8 hp all the way thru 1997, in case anyone else has one between 92 and 97 that can offer any tips. At first I thought maybe there was a problem with the kill switch since it seems like it fits loose and it barely pushes in the tabs (which I assume is how the kill switch works) but I would think that would interrupt spark to the plugs, and I am getting spark.

I guess I'll go out and get spark gap tester and see if I can borrow a tester from the parts store.

The one thing that does strike me as being odd, but may be normal, is some fuel leaks out the air intake. Not much, but enough to tell more is accumulating. It seems to happen while I am pull starting, but it is tough to tell.

I have the fuel primed to the max to where I can't pump the bulb any harder and there is no fuel coming out the carb overflow or anything... so I don't think it is overflow and if it were a stuck float I would think it would keep flowing as I primed, it wouldn't stop like it has.

Boy my shoulders are hating me for doing that compression test after they were already shot. Compression came back at 105 PSI on the top 110 PSI on the bottom. I did the test with the plug removed on the untested cylinder just in case there were any head leaks. It may be even a bit higher than that because the tester had an automotive length thread that would have caused my piston to bottom out on it so I had to use the very short portion that was part of the hose that only had able 3 or 4 threads. It did have a oring ring at the end and I got it pretty snug, but I could see maybe a few PSI escaping on the reading. From what I've read good compression on these particular motors is over 85 - 90 PSI so I think I'm find there.

I did the gap test at 1/4" and it sparked. It is quite bright out so it is hard to tell if it is bright blue or weak, but it seemed to snap pretty good. I will check again at 3/8 and 1/2" once the sun goes down a bit and see.

I'm glad to know the compression looks good at least. Perhaps it has a weak spark, but I'm leaning towards a fuel issue since I can't seem to flood the motor if I tried, but then again why can't I get even a little puff of smoke when I direct inject some fuel into the cylinder? I'm still baffled but at least one thing is crossed off the list now. I wouldn't be so aggrevated by it if the motor hadn't started in god knows when... but seeing it run just yesterday is really frustrating me because I was pretty revved up to go try this motor out this weekend, but that's come to a screeching halt so far.

Thanks again for the replies, I appreciate it.

I got some help so I could check the spark better. I took it all the way out to 1/2" gap and got a strong blue spark on both of them. I wouldn't be surprised if it could go another 1/8" or 1/4" but I didn't go any further. So I've got spark, I've got compression... but for some reason I'm not getting any combustion... and process of elimination would say it has to be fuel delivery, but I still can't fathom why I can't get it to create a single puff of smoke even with putting ether or fuel directly into the cylinders.

Do you think I should just tear down the carb and start cleaning it and see what happens, or could there be another culprit that would give these symptoms?

I took apart the carb and cleaned every aspect of it extensively. It wasn't bad from what I could see though, just a little gunk at the bottom of the bowl. There could have been a port or two clogged though, who knows. But I put it back together and low and behold it started after several pulls for about 10 seconds before it died and I couldn't get it restarted. I waited about 10 minutes and tried again and this time it started up and continued running so long as I was atleast above 1/4 throttle. When I would try to get it down to a lower idle type speed it would die and would take a lot of effort to restart it again. But I did verify there was a strong stream of water coming from the return hose located on the rear starboard of the motor. There is also a little hole in the center near the carry handle and mount that a little bit of water comes out of, and I'm not sure what that it or the volume that should be coming out of it. I wish I had the owner manual (I have one ordered, just not here yet). I have a service manual that is more of a generic "all years and sizes" so only certain info I can learn about through it.

I figured I would make sure it would shift into gear and I got it down to the lowest rev it would sustain and shifted it into gear but the load caused it to die pretty quickly. Not sure if I should have it revved up when engaging, but I would think you want to engage at idle RPM? Or is it ok to pop it into gear at above idle rpm to prevent it from stalling?

After that, once I was again able to start it after some fuss it sounded ok like before at first but then it started to shudder one a couple cycles here and there, almost like it was trying to backfire. I don't think it is a fuel issue as while the carb was off I tested that the bulb/remote tank primed fine and that the fuel pump was consistently pumping fuel as the rope was pulled. Plus, I have the tank mounted higher than the motor right now anyways so it would essentially gravity/siphon feed.

I'm guessing at this point I could have a number of issues... probably mostly relating to the carb settings. There must be an idle jet or idle setting that I need to play with. Perhaps the timing could be an issue too but in the service manual (which is kind of generic for all years and models of OMC outboards) it mentions that this model does not have adjustable timing. It is strange though because what looks to me to be a timing plate has what looks to me to be timing adjustment numbers on it.

I'm not sure where to start first now from here, but at least there is life in it... but goes to show I probably should have gone home and got my trash can so we could have tested it more before buying because I bought it under the assumption it was running perfect, but there are some kinks that need worked out on this for sure... especially before I even think getting more than a couple hundred feet from the boat launch, lol.

Just wanted to let you know I got it running and it seems to be running good. I can get a pretty low idle and shift it also. After I took apart the carb and cleaned every bit of it I followed the steps in the service manual to recalibrate the carb. In case anyone else has this issue here is the procedure.

Screw in the slow speed needle until is gently seated all the way in. Turn it out 2 and 1/2 turns to start there. I am at sea level and it actually took closer to 3 turns out to get it to idle well.

Unscrew the screw that is on the plastic cam follow (that connects to the throttle linkage) until either screw is barely making contact with the cam follower or until the cam follower is just barely making contact with the cam at zero throttle (idle).

Turn in the cracking screw (the one on the throttle linkage with the spring) until it is fully, but lightly compressed, which is approx 4 complete turns after the screw tip makes contact with the throttle lever.

From there you will adjust the cracking screw out to lower the idle if it is too much or screw in the cam follower screw to increase it. They both do the same thing basically but you're mostly out of travel to increase it with the cracking screw.

You want to adjust the low speed needle by 1/8 or less turn adjustments in or out until it idles right at a low idle speed. You must wait 15 seconds for the adjustment to take affect before trying to readjust. If you are at high elevation that would probably mean turning it in (reduce fuel to lean it out), low elevation probably turning it out (increase fuel to richen the mixture).

On the 1992 and up 5-8hp, and possibly the 1991 there are no timing adjustments possible, it is CDI. It is all controlled by the power pack. It threw me off because there are some timing markings on the flywheel but I assume the flywheel is shared between other models perhaps that do not have CDI?

As far as my outboard, I still need to take a look at the lower end. When I put it in tank before I could get it running (just pulling the ropes a zillion times) it started to build up an oil slick at the top of the surface. I couldn't tell if this was old residue from the exhaust coming off it or if perhaps the oring on the lower end got old and dried out and cracked and was leaking out case oil into the tank. It wasn't a ton, but enough to put a thin layer of dirty dark brown oil throughout the surface. The service manual has a supposed drawing of the cooling system on my model but it doesn't seem to line up with mine. On mine from what I can tell there are only two place water comes from... the "tell tale" (peehole), and a small hole just above the fold out carry handle (but it is only a sputter/mist of water). On the diagram it doesn't show what that sputtering hole does and it also indicates that water flows out the lower unit near the prop, but I only thought water came up from the lower unit, not returned through it.

The other thing I need to figure out is how to flush this thing with muffs. It doesn't have a single water pickup port... there is a port right above the cavitation plate but that screen extends down below it also. I'm wondering if I can just tape off the lower part to force the water through the port that the muffs would affect. The reason being is we'll be taking it in the ocean a couple times here soon and I won't be able to bring my tank along and I know it is very important to flush salt water.

Lower end looked good... no water in the oil I could see and not milky. Oil was full, which is good. It did look a little old, but not too bad. I changed it out though of course. No debris or metal in the oil or on the magnet. Everything looks good to go!