Carb adj on Johnson 175

[JJB]

I have just bought a rebuilt 2000 j 175 vxsss engine . I just rebuilt and clean the carbs due to sitting . I have set the floats parallel at 1/32 to the float bowl matting surface as per spec . and 1" on the drop spec . as the manual stated between 11/16 - 1 1/8 spec . for float drop . I clean and installed all new omc repair kits on all the carbs then reinstalled them . After I tinker with the idle air screw i notice two of my carbs were overflowing fuel out of the carbs . I then re adjusted those two floats to a larger setting outside of the 1/32 spec. and it stopped . I have a mis at idle and am going crazy with the adj on the carbs to stop the mis . I have notice that one of my bottom carb and one middle carb are very hard to get the idle screw adj correctly( and both are within the spec adj ) . I have got ride of the mis but took me a long time to get it right and did idle smooth . Then I rev the engine a few times and the mis returned again . any input on getting floats right and the touchy air screws . If I start out with screws all set a 5 turns out it mised a lot . I did set timing and carb syn adj before starting the process . Thanks for the input

 

[angus63]

Re: Carb adj on Johnson 175

Just a thought, but did you address the recirc valves? A miss at idle but runs well otherwise would point me to cleaning the recirc system and hunting for a small air leak around the intakes. Also sour fuel will make idle adjustment tricky.
Good luck

 

[JJB]

Re: Carb adj on Johnson 175

Thanks for you input I haven't check the recirc valves yet . How would you check for vacuum leak around intakes ?

 

[reeldutch]

Re: Carb adj on Johnson 175

get a can of carbcleaner and spray it around the crankcase and other posible airleaks.
you wil hear a big differense when you spray carbcleaner onto the leak.

can you pinpoint wich cylinder is missing or is it hard to tell?

 

[JJB]

Re: Carb adj on Johnson 175

Thanks for the info ,I kind of hard to tell which is missing but will try with the carb cleaner

 

[pak_ratt]

Re: Carb adj on Johnson 175

I have 1996 175 Ocean runner where are the recirculation check valves located and can somepost a picture? I am not sure I am looking in the right place.
Thanks
Tim

 

[Chris1956]

Re: Carb adj on Johnson 175

If it ilike my '98 Johnny, the recirculation hoses are on the outside of the block, and run from about 1/2 up on the cylinders to the back of the intake manifolds, 3 on each side.