1976 Evinrude 85hp Very Hard Starting

timrauch

Cadet
Joined
May 23, 2004
Messages
8
I'm having a lot of trouble getting my motor started. The only way it will start is to squirt a bunch of gas in the carb. I normally have to do this a few times before it will run long enough to keep running. There is good spark. This motor has all new electrical components (power pack, ignition coils, timing base), the carbs have been cleaned and it has a new fuel pump.<br /><br />I'm thinking I may have a leaking crankshaft seal or some other leak into the crank case. This motor sat for 14 years without being used. Does this sound logical? How can I check for leaks with minimal equipment? Any other suggestions?
 

Joe Reeves

Supreme Mariner
Joined
Feb 24, 2002
Messages
13,262
Re: 1976 Evinrude 85hp Very Hard Starting

The fact that the engine starts when you spray a fuel mixture into the carburetor throats would indicate that either fuel is not reaching the carburetors, or they have not been cleaned properly. Clean the jets manually with a solid piece of wire, then blow them out with pressurized air.<br /><br />Also, the following may be of interest.<br /><br />(Compression & Spark Test)<br />(J. Reeves)<br /> <br />1st - Regardless of what problem one might encounter, always start with the basic troubleshooting procedure. Check the compression which should be in the range of 100+ psi (somewhat less on the smaller hp engines) and even on all cylinders.<br /> <br />2nd - With the spark plugs removed, rig up some type of spark tester whereas you can set a gap to be jumped. On magneto ignition systems.... and also the Battery Capacitance Ignition system OMC engines from 1968 to 1972, set the gap to 1/4". On the solid state OMC ignition systems from 1973 to the present, set the gap to 7/16". The spark should jump the gap with a strong blue lightning like flame..... a real strong blue snap!<br /> <br />If there was no change in the spark, on engines from 1973 up, disconnect the RED main electrical plug at the engine. Remove the s/plugs. crank the engine via the starter solenoid (jumper bat term to small 3/8" term nut, not the ground nut) and observe spark. If spark is now okay as stated above, the usual cause is a shorted ignition switch.<br /> <br />If the above checks out as it should, and the engine dies out when throttle is applied, it is usually due to one or both of two things. The carburetors are fouled, in which case the cure would be to remove, clean, and rebuild them..... or the timer base under the flywheel is sticking which would result in a retarded spark.<br /> <br />To check the timer base for sticking (Engine Not Running), spin the prop to align the shifter dog with forward gear and while doing so, put the engine into forward gear. Now, while watching the timer base, slowly apply throttle clear up to full throttle. The timer base should move smoothly all the way up against the black rubber cap that is atached to the end of the full advance spark setting screw. If the timer base sticks, find out why and correct that problem.
 

timrauch

Cadet
Joined
May 23, 2004
Messages
8
Re: 1976 Evinrude 85hp Very Hard Starting

The compression checks out at 125 PSI +- on all 4 cylinders. I've cleaned the carb twice including running a wire through the jets. My thought is that even if fuel is getting into the engine if I have a leak in the crankcase it may not have enough crankcase pressure to push it up into the cylinders and/or the added air is leaning out the mixture.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: 1976 Evinrude 85hp Very Hard Starting

make sure the choke sutters are closing all the way. also make sure the engine can crank at at least 350 rpm with the plugs in. especially if its a single pack model with 4 coils on a bracket on top of the motor.
 
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