Just bought a 1997 Ranger with a 1997 200 EFI ser.# OG558162, approx. 400hrs. Engine has a stutter most noticeable at idle but can be felt at all rpms. Great hole shot and excellent top end. Starts immediately and idles steady except for the stutter/ stumble. Checked compression, all cylinders 115-120 psi. Spark plugs not fouled. I removed the oil injection due to leaking tank and hoses. It had the stutter before oil injection removal. Any ideas would be greatly appreciated. Thanks, Craig.
What is the IDLE TIMING set at, and what is the TPS set at?
What plugs are you running?
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Previous owner had timing and TPS set in August 2018, did not give numbers. Also had plugs changed at the same time, they are NGK- BU8H. l will check the Idle timing and TPS setting.
Last edited by CMOS; 05-07-2019 at 05:27 AM.
Finally had a chance to check timing and TPS. The idle timing is set to 2° ATDC and the TPS is set to .250 closed and 7.5 full throttle.
You can put a timing light on one spark plug at a time and see if you are losing spark when it stutters. If all is well, you can move to the fuel side. Check ECU cannon plug, all ground connections and injector harness for chafing. It may simply be time to have the injection system cleaned, but I would wait for more advise from European(Don) or Joe before going that route.
1999 ProGator 190V
200 Mercury EFI 0G843298
So far spark looks good, I'll give the timing light a shot. Will check all connections again. Thanks for the ideas! It almost feels like a miss, most noticeable at idle.
what prop on boat, move the timming to 6 or 8 atdc this will clean it up a lot at low end idle it up with air valve screw, look between ecu and top of elect pump screw with + , theres a fine line between too rich and to lean and not every boat can be set up the same because of loads and other varibles, make sure spark arm is moving full advance an not lagging, I try to run laser mtrs as lean as I can get away with without a bog makes um smoother and better low speed operation, now this is say your mtr is sound in other ereas reeds pressures and so on ,whatchya think ????
.................................................. ...the scariest thing in life is the unknown ...................................
The prop is a Tempest 25P. I'll give the timing and air valve screw a shot. Thanks for the tips!
one large hole plug in no more other 2 open
.................................................. ...the scariest thing in life is the unknown ...................................
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