2002 YAMAHA 50 HP 4 STROKE PROBLEMS

[SCOOTE]

I NEED HELP! MY MOTOR HAD A BAD MISS AT 2400 RPMS BUT WOULD RUN PERFECT AT 5900 RPMS, SO I WAS TOLD TO CLEAN THE CARBS, SO I DID NOW THE MOTOR WILL NOT PLANE AND 4800 TO 5200 RPMS IS MY MAX WITH A POPING SOUND IN COMBUSTING CHAMBER

 

[rodbolt]

Re: 2002 YAMAHA 50 HP 4 STROKE PROBLEMS

popping is most likly due to a lean carb.
check fuel pump output and if its good,above 3 PSI then do the carbs again. make sure you clean the filters in the carb inlets.

 

[SCOOTE]

Re: 2002 YAMAHA 50 HP 4 STROKE PROBLEMS

THANKS FOR THE HELP, IF THE GASKETS AND ORING LOOK GOOD DO THEY STILL NEED TO BE REPLACED? IS IT IMPORTANT TO CHECK FLOAT LEVELS ON ALL 4 CARBS?

 

[Silvertip]

Re: 2002 YAMAHA 50 HP 4 STROKE PROBLEMS

Yes and Yes. Since you had the carbs off, the linkages have been disturbed so synchronization is necessary. You really need a service manual.

 

[SCOOTE]

Re: 2002 YAMAHA 50 HP 4 STROKE PROBLEMS

GOOD I REPLACED EVERYTHING THAT COULD BE REPLACED WITH THE CARBS. I FOLLOWED THE MANUAL ON SYNC THE CARBS AND SETTING THE MIXTURE SCREW. THE POPPINF SOUND IS GONE, WHEN IN THE WATER I REV THE RPMS UP TO 5900 PERFECT BUT ONCE IN GEAR STILL THE SAME STORY. I REPLACED PLUGS, CHECK COMPRESSION EVERYTHING IS GOOD. FUEL PUMP OVER 3 PSI. ANY IDEAS PLEASE HELP

 

[SCOOTE]

Re: 2002 YAMAHA 50 HP 4 STROKE PROBLEMS

Yes and Yes. Since you had the carbs off, the linkages have been disturbed so synchronization is necessary. You really need a service manual.

happy 4th!! I got the boat to plane today it ran well, it still wouldn't go over 5200 rpms but it had no miss, have any ideas why it is maxing out at 5200?