Rough idle

[rdj629]

I have a 1993 50 hp VRO motor with the VRO system removed by the previous owner. It starts and initially runs great. After running for a while it idles very rough and at times dies while idling. It runs fine at full throttle when warm. Any ideas?
Thanks

 

[oldcatamount]

Re: Rough idle

Sounds like you need to clean/re-build the carbs, primarily the low speed idle circuits.

 

[dazk14]

Re: Rough idle

As I recall, those carbs have adjustable low speed needle valves on the stbd side.

Have you checked the plugs to determine if it is dying lean or rich? Does it require choke when restarting after stalling or does it require increased throttle to restart?

Rotating the adjusters clockwise will lean out the idle mixture and counter-clockwise to richen.

Do you have a service manual?

 

[rdj629]

Re: Rough idle

I do have a service manual but now I seem to have run out of spare time. I repost when I have messed with the carbs.