When is it time to rebuild the carbs?

[AguaSki]

I am still learning my way around marine motors. My current motor is a 1978 140 hp Johnson. I have owned the motor for 3 seasons now, and as far as I can tell the motor is running strong. Nothing seems out of sorts with the way the engine performs, but going into the winter I am thinking of the maintenance I would like to complete before next season, and rebuilding the carbs has surfaced in my head as a possibility. Rebuild kits here on Iboats seem fairly inexpensive. I would think this 30 year old motor has had the carbs rebuilt at least once, but I don't know the the full maintenance history. Is it a waste of money to rebuild the carbs out of routine maintenance, or is it best to wait for noticable problems? What are the symptoms of a carb that needs to be rebuilt?

 

[Silvertip]

Re: When is it time to rebuild the carbs?

Look at it this way -- carb problems often cause very expensive engine damage so why on earth would you wait until you had an issue. Since you have no idea if or when the carbs were done, it makes sense to rebuild them with new kits. If you are in an area that is just getting around to using ethanol blended fuel, it would be a good time to rebuild them. A carburetor that allows one or more cylinders to run lean means the engine is running lean on oil as well. Too little oil means pistons scuff, cylinder walls become scored, and the engine possibly overheats and seizes. If that sounds expensive -- it is! Spend the money, do it right, and enjoy your boat knowing at least that system won't contribute to a major failure.

 

[jtexas]

Re: When is it time to rebuild the carbs?

when it has good spark & good compression but won't get the boat up on plane, or idles poorly, or warm starts get difficult, it's time to rebuild the carbs. or if you just have a general feeling that performance has slipped a bit...she always runs better after a carb rebuild, and there's lots of worse ways to spend an afternoon.........

 

[guy74]

Re: When is it time to rebuild the carbs?

I always rebuilt the carbs every three years when I change the impeller, it's alot easier to get to the shift linkage with the carbs off. Just makes it a good time to do both jobs. That is the scedule I use.

 

[jspringator]

Re: When is it time to rebuild the carbs?

I have a 1975 Evinrude 25 HP (22 CID). The packing on my low speed jet isn't tight. The adjustment linkage keeps it from moving (I think). Requires about 2 1/2 turns out to avoid lean sneeze. This motor is new to me and seems to run and idle good. Should I just leave well enough alone?