Hello all,
I have a 1980 johnson 50 hp that just doesn't want to start and when i finally give up (after lots of cranking head scratching double checking and triple checking of starting procedures) it seems like it fires up. my "trick" is that I take the throttle plates by hand and open them all the way then let go as soon as it fires up. I say trick because it doesn't always work so i don't know if its really helping or just voodoo....
anyhow once it starts it idles ok then starts increasing RPM's until it makes a pop (out of the exhaust) and then returns to a smooth idle and the cycle starts again. on the water once i get it started (which is an embarrassingly long time on the dock with everyone coming and giving their advice on what I'm' doing wrong) it runs pretty good from 1k to 2k rpms and from 2k rpms to WOT it runs fantastic
things i 've checked: my starting procedure straight from this site pump bulb til hard;warm up lever all the way up; ignition on; push key in(i've checked visually that choke plates are working when key is pushed in); turn over for 5 seconds. I try several cycles of this and then get frustrated and start playing with choke no choke warm lever up the down then halfway etc etc. engine just turns over real dry no sputtering or hint that it might want to start
I pulled plugs and in the daylight I can see blue spark on both cylinders not using any testing equipment just removing plug and holding it against the block and watching what happens (hooked up to plug wire of course). the plugs looked ok insulator was tan some black on the electrode and they were wet (but I assume thats because i've been cranking and cranking with no start) but I replaced them anyway brand new champion L77JC4 gapped to .035
moved on to carbs with OMC carb rebuild kit pulled the passage plugs (welch plugs??) and cleaned and cleaned and to be honest everything looked really clean when i started. the kit came with new floats so i installed all of that and set float level with carb body upside down float is level with free end just slightly more elevated than the hinged end.
put it all back together with new carb base gaskets (came in the kit) and attempted to fire it up but it runs exactly the same. very difficult to start and when I take the plates and hold them wide open it will run ( i let go of the plates as soon as it shows life) and then it will idle pretty good but then starts with the increasing speed the pop and then the cycle starts again.
I have observed on muffs and in the water that the tach at idle seems a little goofy like the needle bounces around. then when you get to 2k rpms or so and above the tach smooths out and appears to be really accurate. i have noticed on the muffs that when it idles at 800rpms the tach seems like its working right and when the the surging and pop happen the tach wobbles all around between 1000 and 2000
another observation is that the engine is leaking oil somewhere low on the powerhead. I can see oil mix in the bottom of the cover and it is leaking out somewhere onto the exhaust housing. I can't really tell where its coming from but the part of the engine you can see from the flywheel on down is all dry. it has been suggested to me that the oil leak could be the lower crank seal which would not only leak the oil but would admit air which could cause a lean condition.
SOOOOO: based on all of that does anyone have any advice on whether i'm still looking at a carb problem or an ignition issue and any advice on tests i can run to help figure it all out. does anyone have any opinion on the idea of the crankcase seal? its a fairly cheap part so i'm tempted to pull the powerhead and see what everything looks like and replace the base gasket and crankcase seal if its leaking. air leaking somewhere else? how do i test the fuel pump? i'm just tired of tinkering with this thing and would like to be on the water insteads.
I have a 1980 johnson 50 hp that just doesn't want to start and when i finally give up (after lots of cranking head scratching double checking and triple checking of starting procedures) it seems like it fires up. my "trick" is that I take the throttle plates by hand and open them all the way then let go as soon as it fires up. I say trick because it doesn't always work so i don't know if its really helping or just voodoo....
anyhow once it starts it idles ok then starts increasing RPM's until it makes a pop (out of the exhaust) and then returns to a smooth idle and the cycle starts again. on the water once i get it started (which is an embarrassingly long time on the dock with everyone coming and giving their advice on what I'm' doing wrong) it runs pretty good from 1k to 2k rpms and from 2k rpms to WOT it runs fantastic
things i 've checked: my starting procedure straight from this site pump bulb til hard;warm up lever all the way up; ignition on; push key in(i've checked visually that choke plates are working when key is pushed in); turn over for 5 seconds. I try several cycles of this and then get frustrated and start playing with choke no choke warm lever up the down then halfway etc etc. engine just turns over real dry no sputtering or hint that it might want to start
I pulled plugs and in the daylight I can see blue spark on both cylinders not using any testing equipment just removing plug and holding it against the block and watching what happens (hooked up to plug wire of course). the plugs looked ok insulator was tan some black on the electrode and they were wet (but I assume thats because i've been cranking and cranking with no start) but I replaced them anyway brand new champion L77JC4 gapped to .035
moved on to carbs with OMC carb rebuild kit pulled the passage plugs (welch plugs??) and cleaned and cleaned and to be honest everything looked really clean when i started. the kit came with new floats so i installed all of that and set float level with carb body upside down float is level with free end just slightly more elevated than the hinged end.
put it all back together with new carb base gaskets (came in the kit) and attempted to fire it up but it runs exactly the same. very difficult to start and when I take the plates and hold them wide open it will run ( i let go of the plates as soon as it shows life) and then it will idle pretty good but then starts with the increasing speed the pop and then the cycle starts again.
I have observed on muffs and in the water that the tach at idle seems a little goofy like the needle bounces around. then when you get to 2k rpms or so and above the tach smooths out and appears to be really accurate. i have noticed on the muffs that when it idles at 800rpms the tach seems like its working right and when the the surging and pop happen the tach wobbles all around between 1000 and 2000
another observation is that the engine is leaking oil somewhere low on the powerhead. I can see oil mix in the bottom of the cover and it is leaking out somewhere onto the exhaust housing. I can't really tell where its coming from but the part of the engine you can see from the flywheel on down is all dry. it has been suggested to me that the oil leak could be the lower crank seal which would not only leak the oil but would admit air which could cause a lean condition.
SOOOOO: based on all of that does anyone have any advice on whether i'm still looking at a carb problem or an ignition issue and any advice on tests i can run to help figure it all out. does anyone have any opinion on the idea of the crankcase seal? its a fairly cheap part so i'm tempted to pull the powerhead and see what everything looks like and replace the base gasket and crankcase seal if its leaking. air leaking somewhere else? how do i test the fuel pump? i'm just tired of tinkering with this thing and would like to be on the water insteads.