Re: 1972 9.9hp Mercury - questions
My opinion is I would check compression, both over 100psi or hopefully better and within 10 lbs of each other. Check lower unit lube, these (if original) have a carbon steel drive shaft which is prone to rust. '72 has the phase maker Thunderbolt ignition which consists of 2 green ignition coils, ignition module, 2 coils under flywheel and condenser along with 2 points. A factory manual or Seloc along with a parts list would show all of this. You can check ebay for parts, all of the ignition stuff will add up some. Also double check the serial number to verify '72.
If the motor is in good condition and the compression and lower unit lube looks good, it might be worth horse trading over. Price your ignition parts (easy over $200 if you have to buy everything and get good deals), decide how much you want to put into it and offer the seller the difference. Also agree with above posts, check the compression with your gauge and lower unit lube yourself. $150 sounds a little high for no spark.
