1971 18HP Evinrude Fastwin

[LindenLongRods]

I'm back! Started up yesterday with new fuel pump and started right up. A little cough when idling (still trying to dial in) Then conked out, tried starting again, but no luck. checked spark, seemed to be getting spark from both plugs. Sounded dry like not getting gas again, but I changed fuel pump. Vented cap, stiff bulb, check. So what now? could it be points or condenser, or coil? I changed all of that also. Help I'm at wits end with this engine

 

[Crosbyman]

if compression is ok check spark intensity in open air ....and clean the carb again check inlet needle if sticking

perform blow test after cleaning the carb

 

[racerone]

The term----" seemed to be getting spark "------Means nothing here.----Does spark jump a gap of 1/4" or better on a test device ???----That level of performance is required for easy 1 or 2 pull starting !!

 

[LindenLongRods]

I rebuilt carb but willing to take apart and see if I did something wrong, I also will take flywheel off again to check points. I replaced point, condenser, coils also but also willing to check again. Racerone, when I hold spark plug next to block it jumps but I didn't try a 1/4" though. That seems far. If I was to post a video, would that help? I wish someone in NJ could help. Been working on motor all winter

 

[racerone]

You can make a proper spark test device.------Take 2 or 4 pieces of wire ( even speaker wire )---Glue them on a piece of plywood or cardboard with 1/4" gap between them.----Stick one end in plug boot and clip other end to the block.----With 4 pieces of wire you cold test both ignition systems at the same time !!

 

[Crosbyman]

don't give up... I had a small 4hp driving me nuts last winter

ended up into a Murphy scenario ...bad condenser, coil, plug but the exact combination remains a mystery ...

 

[LindenLongRods]

You can make a proper spark test device.------Take 2 or 4 pieces of wire ( even speaker wire )---Glue them on a piece of plywood or cardboard with 1/4" gap between them.----Stick one end in plug boot and clip other end to the block.----With 4 pieces of wire you cold test both ignition systems at the same time !!

 

[LindenLongRods]

OK I will try it!!!

 

[oldboat1]

Save some time, and buy an open air adjustable tester from an auto parts store. ($10 or so).

 

[LindenLongRods]

Tried again today, took apart Carb (was rebuilt, I didn't do the little caps though) but overall it looked fine, It ran before I did all this work over the winter so I can't imagine what I did wrong. blew it out again. Still no start sounded dry like not getting gas. Could it still be carb?? Took off spark plugs, Spark was whiteish blue, good jump, maybe not 1/4 but they had spark, but they were dirty and oily when I took out. They were brand new. I'm at wits end, ready to pack it in for a new outboard.

 

[racerone]

No offense but how did you conclude that motor ----" sounded dry "-----I am puzzled.----You are aware that plugs laying on the block can show spark, but when in the cylinder with 100 PSI air the will not fire ??----Testing / inspection / trouble shooting must be done.

 

[oldboat1]

You might remove the fuel pump hose at the carb, crank the motor and see if there is gas flow from your new pump. You absolutely need to measure spark to see if the magneto is producing like it should.

 

[LindenLongRods]

Ok I will try that with the fuel pump. I will measure spark also with a tester. either I will buy one or make one. I just say "Dry sounding" because it just sounds like it's not getting gas, it kicks once in while but will not catch and run. Also reattaching the the carb I forgot to hook up the fuel line and gas came out when I pumped the ball, but I will try while cranking the engine. Is there a way to check if fuel is getting to the cylinders? When I checked the plugs they were wet with oil/fuel,but more oily and black. does that mean yes They are getting fuel just not enough? Maybe a fuel delivery problem There wasn't alot of parts on this carb when I rebuilt but maybe I did do something wrong and the bowl was full of fuel, should I maybe take it off again and soak it. How important are replacing the caps?

 

[oldboat1]

The domed caps cover the idle passages, and are important to starting and idling -- as is the fuel feed through the high speed orifice/jet. Soak metal parts in solvent, clean all passages with soft wire or monofilament, then spray with carb spray. Your '71 has an idle mixture needle on top (fuel/air) and it sounds like that may be set too rich. The high speed jet is at the bottom under the cover bolt, and cannot be adjusted. After soaking, clean it with the wire/mono/carbspray. Set the idle screw 1 to 1 1/2 turns open from closed (open is c.clockwise). If it starts, let it warm up and adjust leaner (clockwise) until it backfires or stops, then open 1/4 to 1/2 turn. Tune the motor in a test barrel with water about half way up the leg, or on the boat in the lake.

 

[Fastwinrebuild]

Where in Jersey are you? I have 10 of these 18's maybe I can be of some help. When you cleaned the carb, was it totally taken apart?
Is there any oil sealing out of either the top or bottom crank seals?

 

[LindenLongRods]

Sorry, I haven’t done anything since last weekend, rain and Baseball games. Yes Carb was taken apart and rebuilt It looked clean. I replaced only one cap and didn’t soak it overnight. The motor ran before I ripped it apart, so I didn’t think I needed to go coo coo. Im in North Brunswick, NJ . The plugs look alittle oily and and black when I took out. I plan on checking compression, measuring spark, and disconnecting fuel line before carb and check to see if gas pumps when cranked. Just replaced fuel pump also

 

[oldboat1]

Replaced the nozzle gasket, right? Should have been one in your carb kit. Can't see inside the various passages, so can't really tell by looking whether it's clean/free of fuel varnish.

 

[LindenLongRods]

Thanks so much for responding almost at wits end. It has to be something stupid. Yes I totally rebuilt carb and the jet speed gasket (red w/tab) except the metal caps and jet screw underneath bolt. You need special screwdriver I think. Also I did not soak overnight. Waiting for 2nd rebuild kit to do again but going to EVERTHING this time except the jet screw unless you think I need to

 

[oldboat1]

You need a parts diagram/blowup for the carb, with parts identified. I don't recommend taking out the jets as you risk damaging them. Soak, poke with something that won't damage brass, and spray out with carb spray. I use lacquer thinner for soaking -- need to be able to cut through fuel varnish.

And get an open air spark tester, not the inline type.

Here (carb): http://ww2.iboats.com/Carburetor/dm/cart_id.344573587--session_id.881034497--view_id.1547760

 

[LindenLongRods]

Excellent, I let you know how I make out