Sounds like it might be running on 1 cylinder at times.----Does spark jump a gap of 3/8" or better on a test device.----Sparkplugs are NOT used during this maximum output test.
Need to ask.-----Did you just put gas in it and then took it to the lake ?-----Any service work / inspection done by you ?-----Tested the oil injection system ?----Your first boat ?
If folks have a good 40 year old motor to do some fishing / cruising in your area, why would they sell it ??----Most new motors also require 100+ / hr dealer support.----
Are you pushing key in WHILE cranking it over ?-----Is the ENRICHER solenoid working ?----Remove sparkplugs, put a little fuel into into each cylinder.----Install plugs and crank it over.----Report what happens.
They do not do a lot of boating in January in New York state.-------So a 40 year old , fresh water motor from that area could be a great deal.-----Might be a better motor than a 5 year old Florida , salt water motor.
On a 2 stroke you need to make sure that carburetors are clean.----Blockages may starve a cylinder of oil.-----Run with a timing light to see if one or more cylinders lose spark.
Did a 59 model 5.5 HP for the grandson-----Installed a brand new factory 6 hp crankshaft along with newer rods with needle bearings.-----If you approach this job the right way it will be a sweet runner.----Cheaper to own than some new motors.
The high speed mixture is NOT adjustable on these carburetors !-----Open the low speed mixture screws 1/8th turn at a time.-----Often the bogging will go away.
