91 merc 200hp Xri - idle problems

strelitz

Cadet
Joined
Sep 15, 2012
Messages
7
Serial number odo29976, resurrected after 10 years of no use.

replaced stator (low resistance on one side) , trigger (wire insulation problems) and switch boxes (bias outside specs) all cdi, coils tested OK new plugs NGK buz8h surface gap.

fully rebuilt fuel system everything seems to work fine.

Sync and linked to manual specs.

started first throw but would not idle, continually stalled, rev's just dropped away when fast idle lever was pushed in to engage gear. Once in gear idled very rough (engine seemed to bounce up and down about 2 inches) to 1500 rpm then smoothed out, very slow out of the hole till about 3500 rpm then takes off like a scaled cat! Thinking of removing the idle control box and the detonation controller (is this possible?), what is involved in doing this and what adjustments are made to the timing to compensate?

Prop is a 4 blade 24 pitch which seems to rev out to a little over 6000 rpm

Any help appreciated
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,933
Re: 91 merc 200hp Xri - idle problems

fully rebuilt fuel system everything seems to work fine.
After setting that long you need to check the VST tank for crud, high pressure pump filter(on pump),replace the mechanical fuel pump diaphragm, fuel pressure oin rail, fuel pressure regulator and have injectors cleaned,flow trested and balanced. Cleaners will NOT clean dirty marine injectors(filter) ,additives keep clean injectors clean.
 
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