83 Johnson 90 no fire

[chitty024]

83 johnson 90 no fire....obviously have air...fuel pump pumps when i pull the line off the carb...bowl is full of fuel....can blow through where the line attaches and hear air in throttle body.....so getting gas....when i pull the plugs and hold them against a ground they spark.

My question is, is there a way the spark could be getting blown out inside the cylinder? How would I go about seeing if this is even happening? What would cause it? Weird thing is the other day when i checked for spark it didnt seem like the right bank was sparking so i switched a round the power packs to see if that was the problem..now they all spark.

Could the timing be off? Why would it be off?

thanks for any help you can give me. I know every time i hear go buy the manual but i dont have a lot of extra money and i thought thats what help sections were for on forums. thanks

- Chad

 

[tashasdaddy]

Re: 83 Johnson 90 no fire

have you check compression, what do the plugs look like. the manual helps you understand the motor and what we are talking about. most of us these days do not have extra money.

ethanol poisoning. http://forums.iboats.com/showthread.php?t=299680

 

[chitty024]

Re: 83 Johnson 90 no fire

havent checked compression. it was running great and then just stopped one day. plugs are brand new replaced them the other day and it has ran since i did that. i have read your write up on ethanol poisoning and I was running ethanol 10. It seems it damages the carbs and fuel lines but i seem to be getting plenty of fuel and have since switched to premium fuel in a brand new plastic tank. Didnt change the lines but cleaned the carbs really good and i can blow through them when they are upside down.

im really getting stressed trying to fix this thing. We dont have much time left for boating here in nebraska and i really want to get it out a few more times. I seem to spend 10 times the amount of time fixing it as i do driving it and enjoying it.

 

[bktheking]

Re: 83 Johnson 90 no fire

I have the same motor, they will run on 2 cylinders albeit like a bad o ****e but it should still fire. As far as switching the powerpacks around, you probably had a bad ground and fixed it by switching powerpacks, like I said, these motors will run on 2 cyclinders, i've done it on the lake with a bad ground. They will not plane the boat running like this but they will start. It should also have 2 carbs if memory serves me correct. I've never heard of a motor blowing out the spark on the plugs. Even if compression were bad on one cylinder it should still run,it is after all a four cylinder. What has happened to your motor has had an effect on it's ability to run entirely. First thing i'd do is check compression on all 4 cylinders. Then i'd try to fire it up with a 50:1 mix in a squirt bottle, just cause gas is pumping and bowls are filling doesn't mean anything. Did you check the electric choke circuit, are the butterfly's on the carbs closing when the key is pushed in? My motor would never start unless the choke was engaged while cranking. If that doesn't work then i'd look at timing, pull the flywheel and do a visual, check to see if the key for the flywheel is intact. A broken key will throw off timing and give spark but will never start a motor.

 

[chitty024]

Re: 83 Johnson 90 no fire

ok so i took your advice on spraying the mixed fuel... it fired for about 3 seconds. so obviously theres a clog somewhere in the carb. I have had these things off 3 times and cleaned everything i could however i do not have compressed air here so i couldnt blow them out. Im guessing there is something stuck somewhere that i need to blow out. Which areas should i pay the most attention to so i make sure i get it since i will have to go elsewhere to do it?

thank you for your help it is greatly appreciated. I hope one day i will know enough about this thing to help others myself.

 

[bktheking]

Re: 83 Johnson 90 no fire

I have had these things off 3 times and cleaned everything i could

Eeek 3 times! That's alot of cleaning. See there is a difference between cleaning and CLEANING. Spraying five dollar carb cleaner in them isn't going to do anything (even if you have compressed air). Take them off, take them apart and bring them to a small engine shop that has an ultrasonic cleaner, I swear by them. Then check the internal's carefully, jets especially, and if the omc kits are cheap, put them in as well. Guaranteed the thing will run like new, carb passages are small and like to clog and are hard to clean without industrial carb cleaners/ultrasonic cleaners. I've done the spray and blow air thing and it doesn't last long even if it solves the problem.

 

[bktheking]

Re: 83 Johnson 90 no fire

The other thing I pointed out was the automatic chokes , are they closing when you push the key in? This is very important as it richens the mixture for starting.

 

[chitty024]

Re: 83 Johnson 90 no fire

you guys are awesome! if yall were local i would take you for a ride! she's alive! went and blew the carbs out with air and she fired right up after priming! thank you thank you thank you!

 

[bktheking]

Re: 83 Johnson 90 no fire

you guys are awesome! if yall were local i would take you for a ride! she's alive! went and blew the carbs out with air and she fired right up after priming! thank you thank you thank you!

Awesome news, sounded like fuel delivery for sure, nothing like fixing yer own ride. Now let it run and check each cylinder bank for heat, that's how I quick check to make sure it's firing on all 4, one hot and one cold and it's running on 2.

 

[Lion hunter]

Re: 83 Johnson 90 no fire

On the ethanol poisoning, I would recommend replacing the lines. Even if they are not pluged the ethanol deteriorates the inside of the lines and sends all that gunk to the carb. It's $5 well spent.

 

[tashasdaddy]

Re: 83 Johnson 90 no fire

replace the fuel lines, carb to tank, alcohol resistant, and flush new ones out before connecting the carbs. if not you will be doing it all again. possibly get stranded and towed.

 

[chitty024]

Re: 83 Johnson 90 no fire

already planned on redoing the lines today. there is a kit with the primer bulb and line at my local walmart for 17 bucks and it says alcohol resistant. thanks again guys! and TD thank you again for the parts you sent me for my controls your service was excellent!