Logo

help? 1972 johnson 65 backfires out exhaust

chad26

New member
please help? i bought a boat with no fire, put a whole ignition system on, and now have i think really good spark, it crank and ran for about 10 seconds,then died, and now it just backfires out the exhaust? i have changed the fireing order,and put it back still the same thing! please im out of ideas, any help would be greatly appreciated! thanks
 
Re: help? 72 johnson 65 backfires out exhaust

Will the spark jump a 7/16 gap and is it bright blue?
Have you checked compression
If you squirt some fuel mixture in the carbs will it fire off?
Did you torque the flywheel down, did it shear the key?
 
Re: help? 72 johnson 65 backfires out exhaust

yes it will jump about 1/2 an inch,havent actualy checked compression. will monday. but i did not torque the flywheel,and havent checked the key. that right there i think is it! i had a go cart one time that acted like it was out of time,backfired out the exhaust, i checked everything even looked at the key and it looked fine,but when i pulled the flywheel it had sheered just enough to throw the timeing off! i think thats what happened here,will check fist thing in the morning,and let you know. thank you so much, do you know what the flywheel torques too.
 
Re: help? 72 johnson 65 backfires out exhaust

hey it runs now, it was the shear key. it actualy runs good, except for the exhaust comin out the prop! any ideas i have never even seen an outboard exhaust system, and dont have a clue where to start? thanks again daviet
 
Back
Top