I have a Johnson 33HP, 1968 motor. At slow speed, it pops through the exhaust and the engine jerks hard. The lower gear case in not on the motor yet. Am using a submersible pump to circulate water. Do I need the lower end with propeller connected for testing?<br />Thanks,<br />Jim
The starter on my 33 hp Johnson spins the engine fine with the plugs out. When I put the plugs in the engine balks and will not turn over. Any suggestions.