I have a 7.5 mercury outboard motor serial# 3492069 what year is it and need to take top cover off motor to change spark plugs and what else needs to be changed. It has not run in about 5 years.
Re: What year is my 7.5 mercury with thunderbolt ignition
1973 model<br />Put new water pump in and change the lower unit lube. Put a couple of tablespoons of TCW-3 oil in the spark plug holes and turn it over by hand a few times, before you run it. Use fresh gas. Might have to rebuild and clean the carb.Run a 50:1 mix.<br /><br /> web page
Re: What year is my 7.5 mercury with thunderbolt ignition
I Ditto with RB on the carb rebuild. This is a MUST when a outboard sits that long. Check the compression, if low compression, pour some twc oil in cylinders. If this raises compression, then you are in need of new rings. Good luck and have fun ......Ryan C.
Re: What year is my 7.5 mercury with thunderbolt ignition
About the cover - in the rear of the motor, under the carry handle, there are two levers - one on each side. Pull them downwards and the hood should pop off...<br />- Scott
