70 HP Johnson Problems

[mstritt]

I have a 1983 Johnson 70 HP motor that needs some help. It starts fine but when you apply full throttle it just creeps along. The reeds are fine and the carbs have been rebuilt, any ideas on what the problem might be? Any help would be greatly appreciated, the kids are itchy to go fishing!Thanks!

 

[petryshyn]

Re: 70 HP Johnson Problems

I'm just in the middle of one that had the same complaint. Hope its not the same problem. The upper driveshaft bearing is seizing due to low lubricant. CHECK YOUR LOWER UNIT OIL.....

 

[mstritt]

Re: 70 HP Johnson Problems

thanks for the info but the lower unit oil is fine as I recently serviced it

 

[petryshyn]

Re: 70 HP Johnson Problems

Glad to hear the LU is fine...<br /><br />Sounds like you may have lost a cylinder. Check:<br />> spark at each plug<br />> compression<br />>try squeezing the primer bulb when it boggs. If it improves, its fuel supply related.

 

[mstritt]

Re: 70 HP Johnson Problems

thanks again for the reply, the motor has compression and spark-all have been checked but I have not tried squeezing the bulb, I'll try that next time I'm out