evinrude 9.9hp model 10424S 1974

[nathanglasgow]

Just got this motor and try as i might i can not get it started so looking for a bit of help to get it going.Things done so far are 1.Carb removed and cleaned and float level set. 2. New spark plugs.3.Compression and spark good(nice blue spark which jumps at least 15mm).4.Flywheel removed and points checked and adjusted.Throttle timing check and adjusted(think its called link and sync over in the USA).5.New fuel at 50:1. After all this it still will not start,not even a pop.Tried spraying premix fuel direct into carb and roping it over tons and still nothing.In desperation even tried some Easy Start but again not even a pop.Funny thing is when taking plugs out they are dry! even after several minutes of pulling.The bottom plug, if i delude myself, may just have the slightest of hints of fuel on it.Even tried putting fuel direct into plug holes and warming up plugs with blow torch before reinstalling but again not even a hint of it trying to start.I thought i was a pretty good home outboard mechanic but this has got me stumped.Any ideas would be grateful

 

[R.Johnson]

Re: evinrude 9.9hp model 10424S 1974

Take the fuel connector off of the end of the hose. Try pumping fuel into a container. See if that primer bulb is really working.

 

[nathanglasgow]

Re: evinrude 9.9hp model 10424S 1974

Thanks for the reply but i have done all the basic checks for a non starting motor including checking for fuel supply.As i know fuel is getting to the carb and indeed the float bowl is full of fuel when line is primed i just dont get what is stopping this engine from firing even once.I have just gone as far as injecting fuel past the reed valves with a syringe and a small bore plastic pipe and then quickly reinstalling the carb and pulling faor a good minute and i still have dry plugs!!

 

[Rick.]

Re: evinrude 9.9hp model 10424S 1974

what are the compression numbers? (in lbs. please) Have you tried switching your plug wires? Perhaps they are on the wrong plug. The fact your plugs are dry is concerning. Are you starting it correctly? Engine in neutral, turn tiller as far as it will go counter clockwise, choke on and then pull? One other thing to try is removing a wire from the stop switch just in case it is shorted out. Last thing I would do, is hook it up to a drill and socket set up and crank it over with the drill using the flywheel nut. Try cleaning your points and then re-set them to .020. Best of luck. Rick.

 

[nathanglasgow]

Re: evinrude 9.9hp model 10424S 1974

Rick thanks again for the reply.What you suggest i have all ready covered as most of it is basic 'get the motor going' stuff.All specs are to factory settings.I'm thinking its more of a fuelling problem maybe not enough crankcase vacum being generated to pull fuel through to plugs?maybe upper crankshft seal is worn or a sealing problem between crankcase halves?The deal with the drill and socket set has been used by me on smaller motors but when they start and you dont get the socket off cleanly in time then its v dangerous.I did consider this approach but my 22mm socket has too thick a wall to fit into the flywheel nut recess.Compression is about 7 Bar.(All metric in good old Europe!)1 bar=1atmosphere=about 14lbs

 

[nathanglasgow]

Re: evinrude 9.9hp model 10424S 1974

Rick thanks again for the reply.What you suggest i have all ready covered as most of it is basic 'get the motor going' stuff.All specs are to factory settings.I'm thinking its more of a fuelling problem maybe not enough crankcase vacum being generated to pull fuel through to plugs?maybe upper crankshft seal is worn or a sealing problem between crankcase halves?The deal with the drill and socket set has been used by me on smaller motors but when they start and you dont get the socket off cleanly in time then its v dangerous.I did consider this approach but my 22mm socket has too thick a wall to fit into the flywheel nut recess.Compression is about 7 Bar.(All metric in good old Europe!)1 bar=1atmosphere=about 14lbs

 

[nathanglasgow]

Re: evinrude 9.9hp model 10424S 1974

Rick thanks again for the reply.What you suggest i have all ready covered as most of it is basic 'get the motor going' stuff.All specs are to factory settings.I'm thinking its more of a fuelling problem maybe not enough crankcase vacum being generated to pull fuel through to plugs?maybe upper crankshft seal is worn or a sealing problem between crankcase halves?The deal with the drill and socket set has been used by me on smaller motors but when they start and you dont get the socket off cleanly in time then its v dangerous.I did consider this approach but my 22mm socket has too thick a wall to fit into the flywheel nut recess.Compression is about 7 Bar.(All metric in good old Europe!)1 bar=1atmosphere=about 14lbs

 

[steelespike]

Re: evinrude 9.9hp model 10424S 1974

If it doesn't fire with fuel put in the plug hole it must be a sperk issue.Pull the plugs and crank it over.Can you feel crankcase pressure hear a little
puk puk noise from the crankcase?Did you torque the Flywheel nut?
If not check the flywheel key it may be partially sheared.
Check the plug wires for chafing maybe they are shorting when installed on the plugs. Check the resistance on the plug wires.When the plugs are under pressure its harder for the spark to jump.Juice my simply be going to ground
from the wires.Have the coils been replaced?These are the weak point and would not surprise me that plugs don't fire under pressure.Are the coils discollored,sweaty looking cracked or stained?If you did replace the coils did you get the wires fully inserted into the coils?Perhaps someone put resistance wires on instead of solid core.

 

[jay mendoza]

Re: evinrude 9.9hp model 10424S 1974

OK, this may sound a bit funny, but it happened to me:
Are the plug wires reversed?, Or better yet, are the two wires from the coils to the points reversed at the Packard connectors? Either one of these conditions will cause it not to fire.

Can you hear the reed valves honking/wheezing as you pull the engine through? If not, you may have an air leak of some kind.

The other thing is to check that the timing is correct, as it could have backfired and sheared the flywheel key, which would make the timing so far off it will not run.

 

[kbait]

Re: evinrude 9.9hp model 10424S 1974

With compression and proper spark, the motor MUST fire briefly when you squirt some premix into the cylinders through the plug holes. Concentrate on the ignition. Use a spark tester, and be sure you get at least a 1/4" blue lightning bolt from both plug wires, and confirm that each wire is firing the correct cylinder, at the correct time.

 

[nathanglasgow]

Re: evinrude 9.9hp model 10424S 1974

It runs now.It was a fuel problem.The reed valves were stuck shut when i removed the intake manifold.They were stuck shut by loads of old part-solidified oil and a small bit of rust.Looks like someone in the past did too good a job of winterizing the motor and poured alot of what looks like used engine oil into the motor.I cleaned out what i could reach with old toothbrushes and acetone.Ran very smokey for first 5 mins the settled down.