1978 9.9hp evinrude problems

[rjr13713]

Re: 1978 9.9hp evinrude problems

well got it out on the river today... Got it started for a few minutes then it just died. Kept trying to get it running and finally got it going again, put it in gear and it died again. I'm pretty sure this time it was getting flooded. I could smell a lot of gas and when we pulled the spark plugs they were wet. I had spark on them though when I held them against the motor. I couldnt see any spark when I just held the spark plug up though. Shouldn't I be able to see a small spark in the gap on the plug? Could I have bad spark plugs too? I may end up taking it into a mechanic pretty soon. Its really weird because it was running fine yesterday afternoon after I got the fuel pump rebuilt right and everything tightened down really good.

 

[Rick.]

Re: 1978 9.9hp evinrude problems

Darn. Sorry to hear that. In a barrel the motor has no load which is the easiest environment for it. The one thing that comes to mind is the need to reset the slow speed needle on the water. Usually needs to be enriched a bit from the barrel run. If I were a thinking man I might have mentioned that yesterday. Rick.

 

[petryshyn]

Re: 1978 9.9hp evinrude problems

Be sure you have good spark. The coils of that vintage usually fail by now.....Check them for cracks.

 

[rjr13713]

Re: 1978 9.9hp evinrude problems

It seems to have good spark. I tested both spark plugs against the motor and got a nice arc, nailed me pretty good in the process lol. When I held them in the air though to see if the spark plugs were getting an arc in that little gap I didn't see one. I tried adjusting the low speed needle from all the way in and backed it out quite a bit and it didnt seem to have any effect.

 

[OptsyEagle]

Re: 1978 9.9hp evinrude problems

I am not sure exactly what you are doing when you say you hold up the spark plugs and do not see a spark. The middle nut part of the spark plug is the ground and it needs to be in contact with the powerhead to close the circuit and allow for a spark. So if you were just holding it up with the plug boot on, but no contact for ground, it will not spark and that is normal.

In any event it does appear that your problem is a fuel problem. Since you said that you can revive the motor by squeezing the primer bulb, I doubt it is a carburetor problem, but this can be isolated away, anyways. If I were you I would hook up your tank and line and disconnect the fuel hose at your carb. I would then pull the starter rope (Oh yeah, disconnect your spark plugs first so it doesn't start up on you) and verify that fuel is pulsating out of the line you just disconnected. In other words your fuel pumping system is working. If not, then it is not your carb. Your carb is not getting any fuel.

Now if fuel doesn't come out then it is either your pump, hose, tank or an air leak. Since you said that you have used a new hose and tank, I will assume they are not the problem and I would then disconnect the fuel line to the fuel pump at the motor's quick connect. Stick that end into a jar of fuel and pull the starter cord again. If no fuel pulsates out then your problem has been isolated to your fuel pump. If it does, then I would suspect some sort of air leak, perhaps in your connectors.

That is what I would do, anyways. By the way, when you rebuilt your fuel pump did you do the blow test. You put your lips on input of the fuel pump and blow and then the output of the fuel pump and blow. On the input, air should flow and when you blow in the output it should not. Did you do this?

 

[AlTn]

Re: 1978 9.9hp evinrude problems

another fuel delivery tool is a clear piece of vinyl tubing running from the pump to the carb...once started, this line should remain full with no air bubbles....bubbles can indicate an air leak in one of the fittings or in the pump itself

 

[mekkamaz]

Re: 1978 9.9hp evinrude problems

Maybe you use the choke longer than you need, and as you was playing with the needle maybe used time to time to get in on....flooding
your carb...But if this is not the case, I think float level is up or valve is not closing...I used to start my 1981 7.5 when flooded by opening full throttle and pull several times til it starts, then back up just to no over-rev the little piece....then it warms and run nice, but this in cse of overchoking...

 

[jmendoza]

Re: 1978 9.9hp evinrude problems

One thing you need to check here is if the engine block is getting good and warm, it should be uncomfortable to hold your hand on the block/head for more than about 10-15 seconds, indicating that the thermostat is doing it's job and keeping the engine at the proper temp. Without the thermostat, the engine will die at anything less than full throttle and foul plugs and smell gassy, I know, mine did not have a thermostat and did this to me.

To eliminate fuel system problems, run the engine with a fuel line directly to the carb, gravity feed from an elevated fuel source using a long piece of hose. This eliminates the fuel tank, line, squeeze bulb, fittings, and fuel pump from the equation. If the problem persists, and the engine does warm up, it could be both of your carbs have an issue or have the low speed needle adjusted too rich.

BTW, the spark plugs threaded body have to be grounded to the block to throw spark.

 

[kbait]

Re: 1978 9.9hp evinrude problems

Did you replace the fuel line from pump to carb? Ethanol in fuel can dry out the inside of that line and 'slough' off and there's no screen past the fuel pump to catch it, gumming up your freshly cleaned carb. Doesn't sound like your particular issue, but replace it anyway (5/32" line).
That motor has CD ignition. You need to use Champion QL77JC4 plugs for that ignition type. If your using UL81C's, they are for points ignition motors ('74-'76), and will not operate correctly. Also, even if you have the correct plug, check your gap (.030"). CD motors.. especially 9.9/15hp tend to eat up the plug gap over time, and can be MUCH too wide for proper operation. Good luck!

 

[Will Bark]

Re: 1978 9.9hp evinrude problems

If you have proved that your pump is good and you have no air leaks from tank to pump and the tank vent is open and the pickup in the tank is clean; then what you have left is the carb and the ignition. I have a 77 15hp Rude that I had to adjust the float drop to 1&1/2" to keep enough fuel in the bowl to run the engine. If that doesn't do it then look to your coils or powerpack heating up and dropping out. Had that happen also. Good luck.