2.5 mercruiser with 3.0 head and intake getting no spark from coil..

[killerkawi713]

I have a 1985 mercruiser 2.5 liter that I put a 3.0 liter head and intake on.. motor crank over great but is getting no spark from the coil.. I volt metered the coil power wire and it has 13.85 when ignition is in the on position.. but when I crank the motor it drops to 6.5 volts and creates no spark out the coil at all.. any suggestions on the problem? all the wires look good and have the 12 volts going thru them when ignition is on.. points look good and are clean and have volts thru them when they are suppose to.. gap is good.. I just cant figure out why its dropping in volts and not creating spark..

 

[Scott Danforth]

File the points, use a dwell meter to set them. Minor corrosion on the points happens if they sit for too long without use. Make sure you have a good condenser

Also, the coil fires when the point contact opens

 

[killerkawi713]

well thank you for the reply.. I got it running.. I replaced everything thru the system and put a new 750 cca battery in it and have got tons of spark now and got the motor to fire up.. is running great now..