60hp johnson vro very rough idle

[harold341]

the carbs have rebuild by a pro, i checked compression all 3 had 120 to 122,i replace all fuel line and filters. i have 1/4 in. blue spark on each spark plug tester, i installed new plugs, tried to adjust carb turning screws had little or no effect i linked and syn fuel to timing no change i'm thinking vac. leak maybe vro is disconnected running 50/1 mix any ideas? thanks

 

[SS140]

Re: 60hp johnson vro very rough idle

Pro? Its hard to find a good pro these days.

I've got 10 bucks on a low speed jet. Hope ya figure it out.

Best of luck

 

[tashasdaddy]

Re: 60hp johnson vro very rough idle

60hp johnson vro very rough idle, which one???? year model #. there have been 60 johnsons, since the 1960's.

 

[harold341]

Re: 60hp johnson vro very rough idle

1988 model

 

[tashasdaddy]

Re: 60hp johnson vro very rough idle

no idea what screw you are trying to adjust, as there are not any adjustments on those carbs, they are fixed jets.

Ethanol and fuel lines
replace all fuel line with Alcohol resistant lines. Ethanol deteriorates, the rubber lines, then they start to sluff off on the inside, going directly to the carbs. Settling to the bottom of the bowl. Contaminating the carbs low speed pickup tube and high speed jets. clean a rebuild carbs, flushing fuel line before connecting to carbs.

 

[HybridMX6]

Re: 60hp johnson vro very rough idle

does it have idle speed screws? Mine does, but it's a '93 60hp, not an '88. Mine idled like crap after the rebuild, but it turned out to be throttle linkage and the idle speed screws needed adjustment. Purrs like a kitten now.
Even if you just had the carbs rebuilt, that doesn't rule out something having been in the fuel lines, and when you hooked it all back up that something could have made it's way into the low speed jets.

 

[harold341]

Re: 60hp johnson vro very rough idle

i replaced ALL the fuel lines ethanol resitant line

 

[tashasdaddy]

Re: 60hp johnson vro very rough idle

1993 has a mixture screw, 1988 does not.

 

[harold341]

Re: 60hp johnson vro very rough idle

1993 has a mixture screw, 1988 does not.

the guy i bought the boat from bought the boat new in 88 and said engine was the orignal that came with the boat will 93 model carbs fit a 88?

 

[Boss Hawg]

Re: 60hp johnson vro very rough idle

Forgive me for asking if you're used to OB's but it is not going to idle like a fine tuned Chevy How rough is your idle? A OB idle is rough to them that are'nt used to them

 

[harold341]

Re: 60hp johnson vro very rough idle

rough enough to shake a 24ft pontoon ,i can handle the rough idle the going dead when docking that i can't handle and the going dead in the no wake zone the is turned up to1200 rpms and still dies i'm at a lost