Low RPM sputtering

[Hardcore]

my 1991 115hp johnson vro2 has a low speed quirk.

Symptom: it misses periodically when idling, especially after having run at higher rpms. sometimes it will cut out all together. if i pump the bulb quickly it fixes it for a time. seems to be a fuel issue.

What i've done to fix it to no avail: new fuel line, filters and bulb from tank to pump. rebuilt the carbs, linked and synced, new plugs, new thermostats.

the bulb still gets soft at low rpms but the boat does great at higher speeds and has power. any ideas? thanks.

 

[cdoliver]

Re: Low RPM sputtering

compression???

 

[ezeke]

Re: Low RPM sputtering

You could check everything again for an air leak in the fuel system. Put a little pressure on the primer bulb and see if you can spot any fuel leak at all, especially around the fuel pump and carburetors. Is there much smoke at idle?

You might also want to check the temperature of the cylinder heads while idling.

 

[coolguy147]

Re: Low RPM sputtering

well if compression is ok then its carbs. since ur pumping fuel its therefore adding more fuel right? dont think its a fuel pump since its only at low rpm problems right? either ur carbs r dirty or the carbs need adjusting again.

when was the last time u serviced it or done work on the motor?