Johnson 48 trouble?

[Jbridered]

I have a 1993 johnson 48 and while going full throttle it suddenly went down to about idle and then would kick back up to normal. It then went back down and stayed. I pumped the bulb while running full throttle and it made no difference. I pulled the boat out of the water and clean the carbs that were already clean just to find that wasnt the problem. When i put it back in the water and cranked the motor it idled rough until i pulled the lower plug wire. How can my motor run smooth or better with the bottom plug wire pulled. Could this be a powerpack issue? This motor has never compared to the speed and power of my old 1983 evinrude 50 with the same prop.

 

[bktheking]

Re: Johnson 48 trouble?

Did you try pulling the lower plug and inspecting the plug? Could be a bad plug, wrong plugs, bad gap, bad plug wire.

 

[kenmyfam]

Re: Johnson 48 trouble?

Time for the basic health check.
Compression
Spark
Fuel delivery
Plug condition

 

[tashasdaddy]

Re: Johnson 48 trouble?

OK, you need to mark you flywheel and test with a timing light. you will find the timing pointer next to the flywheel, not pull you plugs, hold a pencil in the plug hole rotate the flywheel until the piston is all the way out. put a mark on the flywheel at the pointer. do the same on for the other piston. now with a induction timing light. see of the plugs are firing at the same time. this does happen occasionally, and it is a power pack or timing plate problem.

 

[Jbridered]

Re: Johnson 48 trouble?

Yeah i had some plug wires from my old 50hp and it made no difference. Both spark plugs looked fine but i guess i could try some new ones. I really think its a tiiming problem and thanks for all the advice.