Yamaha90hptrouble
New member
Hi everybody if anybody could throw my way some words of advice would be greatly appriciated !!!
My 1997 90hp 2 stroke yamaha outboard is making me crazy ....
The engine starts no problem and idles fine but as soon as i put it in gear it wont give me full power and occasionally stalls ....for about 20 min ....then like magic it will spark and run fine for the rest of the day ....until the next time i put it in the water.
I think i have identify the problem as electric ....intermittent spark on the middle cylinder( has 3 cylinders):
-carbs rebuild twice
-fuel pump and lines checked
-swapped spark plugs and ingition coils and the problem stay with the middle cylinder
-i check the spark on the plugs with the engine at idle and didn't have a spark on the middle plug, tried few minutes later and i did have a spark.
Could it be a faulty cdi unit ??? That is the conclusion that i arrive to but i would like another opinion before i start to look for a super expensive cdi unit.
I disconnect and connect again all the wiring and check all the earths.
The other day in took the boat out with a friend and i had the same problem (wont give me full power) and he twisted the plug cap while i was giving full throttle and the pug started to spark and the engine ran fine for the rest of the day....swapped again the plugs and the coils went out a day later ...same problem on the same cylinder ...twisted the spark plug cap while giving full throttle ....no change ....drove it around the marina for 20 minutes and then like magic the middle plug started to spark and the engine run fine for the rest of the day.
Any ideas?????
I live in a remote area and the only mechanic in the area is super busy so i am on my own on this one.
My 1997 90hp 2 stroke yamaha outboard is making me crazy ....
The engine starts no problem and idles fine but as soon as i put it in gear it wont give me full power and occasionally stalls ....for about 20 min ....then like magic it will spark and run fine for the rest of the day ....until the next time i put it in the water.
I think i have identify the problem as electric ....intermittent spark on the middle cylinder( has 3 cylinders):
-carbs rebuild twice
-fuel pump and lines checked
-swapped spark plugs and ingition coils and the problem stay with the middle cylinder
-i check the spark on the plugs with the engine at idle and didn't have a spark on the middle plug, tried few minutes later and i did have a spark.
Could it be a faulty cdi unit ??? That is the conclusion that i arrive to but i would like another opinion before i start to look for a super expensive cdi unit.
I disconnect and connect again all the wiring and check all the earths.
The other day in took the boat out with a friend and i had the same problem (wont give me full power) and he twisted the plug cap while i was giving full throttle and the pug started to spark and the engine ran fine for the rest of the day....swapped again the plugs and the coils went out a day later ...same problem on the same cylinder ...twisted the spark plug cap while giving full throttle ....no change ....drove it around the marina for 20 minutes and then like magic the middle plug started to spark and the engine run fine for the rest of the day.
Any ideas?????
I live in a remote area and the only mechanic in the area is super busy so i am on my own on this one.