1982 90 hp johson runs rough

[oklahomaduckhunter]

I recently found that i had a bad power pack on my #1 head and replaced it - it is now firing but it runs rough most of the time but every once in a while it smooths out and seems to have a lot more power - but it is inconsistent - what could be causing this?

 

[HighTrim]

Re: 1982 90 hp johson runs rough

Welcome to iboats. Sometimes a rough running engine can be due to faulty isolation diodes in the power pack, but you replaced it. For starters I would do a spark and compression test to ensure I had fire on all cylinders, and I had a viable base to work with. If you are getting spark, and compression is good, look to the fuel system. Will spraying pre mix into the throat of the carbs allow smooter idle? What about choking it out, does that help? Will pumping the primer bulb pick it back up again? How are the hoses and connections, no leaks? Let us know what you find.

 

[flabum]

Re: 1982 90 hp johson runs rough

Also, check the grounds on the coils...remove them and clean any corrosion

 

[emdsapmgr]

Re: 1982 90 hp johson runs rough

Check the stator output. It can cause intermittent spark, even with two good power packs.

 

[ezeke]

Re: 1982 90 hp johson runs rough

Check your ignition coils; they can be off and on when they are failing. Bad coils can kill a good powerpack.

You may find the CDI electronics Troubleshooting Guide helpful. You can download it from their website at cdielectronics .com

 

[HighTrim]

Re: 1982 90 hp johson runs rough

Here is the link Ezeke spoke of, very handy, and will show how to test all of the above.

"http://cdielectronics.com/portals/0/...ide%202006.pdf"