1973 40h.p. Johnson.....not getting full throttle

[gordyB]

hi guys....on my 40 hp johnson i gan get full throttle in nuetral but when in gear it only gets up to about hlf speed with throttle wide open...i just got a carb kit and did all that...went out again and this time i got full throtle for a bit but then the same problem occured...am i missing something????

 

[marinegrh]

Re: 1973 40h.p. Johnson.....not getting full throttle

have you shot compression on the engine and fire, post the numbers when you can<br /><br />good luck

 

[rickdb1boat]

Re: 1973 40h.p. Johnson.....not getting full throttle

Are you sure your throttle plates are opening all the way? Push your control to full forward and look in the carbs to make sure the flaps are all the way open. Might have a linkage problem. Good place to start before we really get into it. Running in neutral really means nothing as far as performance is concerned. There is no back-pressure or load. No water in the gas? No overheating? Good Spark on both plugs? Compression OK? These are some of the other things to look at if the carbs are OK.

 

[The Marine Doctor]

Re: 1973 40h.p. Johnson.....not getting full throttle

Are you using an old metal gas tank?<br /><br />They rust inside and cause all kinds of debris to enter the carb.<br /><br />TMD

 

[gordyB]

Re: 1973 40h.p. Johnson.....not getting full throttle

thanks guys.....i did check my gastank...it is plastic and there was some water in the gas....throttle plates open all the way....now it fires up and runs until it seems the float bowl is empty then it stalls<br />could it be the fuel pump...how would i check it?