Logo

1987 DT 75 power loss

Mac 89

New member
Had the boat out running about 3800 RPM when I hit three four to five foot swells the engine fell off to about 2000 RPM no alarms. Limped back the dock real rough idle. I've been troubleshooting it ever since and will try to keep this short. Gas is fresh with marine Stabil and marine heet it it. New filters checked for water in the separator none. Spark is strong and blue, new plugs. Top and middle plugs are firing bottom is not. Compression is 148 top and middle bottom is 141. This is a rebuild with only about 12 hrs on it. Cleaned the carbs all passages are clear re-did the bottom one three times to make sure good fuel to all three. With the engine running I plugged off the top and middle carbs with my hand, the engine tried to die both times. The bottom carb was barely sucking a spewed fuel on my hand. Is this bad reeds? I've been running it on 50:1 premix while testing and onfirmed the oil injection is working. Sorry for the long post. I'm really frustrated thanks for any help.
 
Back
Top