Need help evinrude 48 at wits end

[I32460]

I recently purchased key west with 48 evinrude boat had set up 12 years.First thing cleaned tank drained fuel new water pump.First time out boat cranks idles fine but will not run full throttle just bogged down.So next rebuilt carbs payed very close attention to floats,replaced every gas line and primer,new plugs.No change I was convinced it was sucking air went back over every connection everywhere,purchased new 6 gallon tank,new fuel pump.No change went back through carbs rechecked connections everywhere added inline electric fuel pump,for diagnostic purpose still nothing.Is there a better way to check the electronics other than purchase and hope.I will add boat will run half throttle all day and checked compression which was fine it runs different with key pushed in not better

 

[stresspoint]

go over the carbs again , ultrasonic cleaning is the best option.

failing that , look for a corroded or bad wire connection or ground around the coil area

 

[racerone]

Model # is ?-----Post the actual compression values.-----Checked / cleaned the high speed jets that are screwed into bottom of float bowl ?----Does spark jump a gap of at least 3/8" on both leads ?----Checked flywheel key?----Checked fuel pump diaphragm?

 

[I32460]

Model # is ?-----Post the actual compression values.-----Checked / cleaned the high speed jets that are screwed into bottom of float bowl ?----Does spark jump a gap of at least 3/8" on both leads ?----Checked flywheel key?----Checked fuel pump diaphragm?

E48es and I can’t make out rest it’s a 88 model evinrude compression around 98 on both and yes to everything else

 

[racerone]

Checked reed valves ?---Compression may be a bit low.

 

[stresspoint]

is it running on both cylinders @ higher RPM when it bogs .
inline spark tester in place to check spark and a look down the carbs will determine if fuel is sucking through.

 

[brodmann]

I've attached a blown up diagram of your carb. I hope it's yours, the year model is 1988. If it's been sitting 12 years, I'm sure all the gas evaporated in the carbs and that usually leaves a good coat of sticky varnish on the internals. You can buy a gallon can of carb cleaner with a basket in it at any auto parts store. I'd completely dismantle it and soak it for a day or two. You'll need carb kits. The plug #5 will need to be removed and the passages beneath it need to be cleaned out. Forced air is best, but a can of carb cleaner with the small straw attached will work too. The high speed jet is #19. It's probably going to be very difficult to get out. I'd spray carb cleaner and/or forced air through it from the large access hold in the top of the bowl as well as through the hole where the drain scew comes out. You can shine a small flashlight into the bowl and lood through the drain scew hole to see if the opening in the jet is perfectly round and clean. I would also highly recommend getting a spark gap tool at an auto parts store. You can probably pick up an adjustable one for around $10. Look for a good strong spark that can jump at least 3/8", like Racerone recommended. If you get the carb kit (you'll need it for the replacement plug that you will remove) and if it passes the spark gap test, The only other possible problem would be spark timing. You'd need to find the procedure for a link and sync to fine tune your timing.

https://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1988&hp=48&model=E48ESLCCC&manufacturer=Evinrude&section=Carburetor

 

[saltchuckmatt]

E48es and I can’t make out rest it’s a 88 model evinrude compression around 98 on both and yes to everything else

The e and the s suggest 1990....not sure if anything is different though. Either your not doing a complete carb redo or your spark is weak. I'm going with your spark. Buy one or one like this and make sure your jumping 3/8 or better and it's a nice blue arc. Inline spark testers are inferior.

CDI Electronics 511-9766 Enclosed Adjustable Spark Gap Tester - 8 Cyl https://a.co/d/jaaDhV3

You might get more compression by removing the head, sanding it flat and replacing the head gasket.

 

[racerone]

Pictures would tell the difference between a 1988 and 1990 model in 2 seconds.-----

 

[ct1762@gmail.com]

these are up around 150psi when I do rebuilds. every. time. 98psi is a bit odd. might be your gauge, or the piston skirts are shot.