merc. 3.0 idle issues

[yamahardro1]

hey guys,
got a 87 merc 3.0 recently and have run through itafter it satr for 2 years. new starter, plug, rotor, condenser, points, fuel pump, oil and filter change, fuel water seperator.

to get to engine to start, has to be at 1/4 throttle, once running it will race up to ~3k rpm's and as soon as i back it down it dies right out. start it back up at 1/4 throttle, seem ok again, throttle response is rather crappy, back it down slowly from 1/4 and it cuts right out.

i took the carburetor off and cleaned thoroughly, float was not stuck, plunger for accel. pump intact and working properly. both jets are spraying.. re-installed carb with all new gaskets and check, still having the same problems.

please help, thanks!

 

[libellav15]

Re: merc. 3.0 idle issues

hi mate

have you definitely got a healthy spark on all pots?

did you change leads and plugs?

cheers

adam

 

[Bifflefan]

Re: merc. 3.0 idle issues

took the carburetor off and cleaned thoroughly

You cleaned it in Carb Dip fully submerged for at least 2 hours and rinsed with water and blown out with air and let dry before reassembly.

If no to any of those, its not clean.
The air bypass holes are very small and can be hard to clean with carb spray.

 

[yamahardro1]

Re: merc. 3.0 idle issues

yes, the spark is great on all cylinders

and yes i used a carb dip as well as an initial spray with carb clean.

thanks for the replies, i'll keep working on her til i get it right