1960's/70's Johnson 75hp motor questions

[focalf5]

Ok, I have a dinosaur of a motor and I have been searching around the site for a little while today and I think someone here may be able to help me out. I only paid $300 for this boat with the motor so I dont want to take it to a marine shop that charges 10 times as much as the boat is worth. I bought it to mess around with as a little project boat but I am new to the marine world. I will keep this as short as possible, I know a good bit about cars but not anything at all about outboards. The last registration on the boat is 75 but I was told the motor is probably a 60's model. It is a johnson 4 cylinder w/ a coil and distributor. My problem is that I am not getting any fire out of the coil and I have replaced it the other day w/ a new one and even swapped it out thinking it was bad. I have rewired everything that goes from the relay box to the stator/ coil/ distributor. I am still not gettin any fire, I understand that the stator could be bad but am I wrong by saying the motor would still fire even if the stator was bad? I am gonna try and change the points is the dist but other than that I dont know what else to do. My BIG QUESTION is does this coil have to be grounded, I know in a car it is not grounded but DOES THE COIL HAVE TO BE GROUNDED TO THE BLOCK/BATTERY? If any of you guys have any advice I would be greatly appreciative. BTW I have checked compression and it is 105 on 2 cylinders and 100 on 2, does that sound alright for the 75hp? Also if anyone lives in the Mid GA/Alabama line area and would be interested in helping a novice out then I wouldnt be able to thank you enough. Thanks again for any and all advice.

[bassboy1]

You couldn't get me to touch that motor with a 10 foot pole, and I like older and ancient Johnnyrudes. Yours should have an electric shift lower unit, which is one of the stupidest shifting designs ever created. The solenoids wear out, and there are no new ones being made. Personally, I wouldn't spend anymore money on that fat 75, and get you a 1973 or newer 3 cyl. 75 Johnnyrude (hydromechanical shift) or better yet a 1978 or newer 3 cyl 75 (fully mechanical shift). Those 3 cyls. are great motors, will last forever, are reasonably good on fuel, especially in comparison to that fat 75, and are dang near bulletproof.

But, then again, I couldn't trust other people when they said not to mess with the elec. shift motors, and had to make the mistake myself. You could take that route as well, and keep working on yours

[LIQUID NIRVANA]

Get yourself a workshop manual. Problem is probably the rotor in the distributor. The belt timing should be checked as well. EASY to work on. Post the model & serial number & I will post the Sales brochure for you to look at here. These motors were created in 1960 & went thru 1965, then updated to an 80hp. Great motor in their day. 89.5 cubic inch. This engine powerhead ended up being a 100hp. Am happy to help. I repeat "EASY TO WORK ON" Parts might be a problem though, after all it is over 40 years old. Check gearcase for water as well. The "selectric" (Evinrude) or "electramatic" (Johnson) gearcase remained in service till the 1968 100hp so it wasn't that bad. The 1960 & 1961 had a standard mechanical gearshift. They were a good servicable motor in their day.

Ken