1991 johnson 40 hp only runs when choked HELP!

replicaracks

Cadet
Joined
Feb 28, 2009
Messages
16
hey guys I just bought a 1991 pontoon with a 40 hp Johnson vro,the vro has been removed and a non vro fuel pump put on, the boat has been sitting 2 years,I charged the battery, and drained and cleaned tank , filled with new 50:1 mix, motor started right up, problem is it will only run for 5-10 sec then die, unless I keep pressing the key in and choking it, then it will idle and rev up as long as I keep choking it. If I keep pumping the fuel bulb, I still dies pumping the fuel bulb seems to have no affect as far as keeping it running .Ive ran a compression test and both cylinders are at 135lbs ,appears to have good spark.now should I tear down the carbs and rebuild them?, or do you all think it is something else? how do I test the fuel pump and make sure its doing like it should?any info is appreciated
 

Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: 1991 johnson 40 hp only runs when choked HELP!

If the spark is good and the compression is good and you have fuel flow to the carbs, pull the carbs and clean them.
 
Top