Does the mercruiser ignition system have a preset timing advance on the thunderbolt 4 system? I have a 1985 four winns liberator. I know some one has been in the engine because it has a performance cam and a rough idle. Engine doesn't ship. Unfortunatly I cannot contact the previous owner to find out what's in the engine. I'm going to try it out tomorrow and see what happens. I installed an aftermarket GM H.E.I dist, made for marine app. Also does anyone have trimtabs for sale? Seemed like the engine was flat and low on power. Fuel pressure ok. 5.7L edlebrock 4BBL and intake. This was before I installed the dist.
