'83 Johnson 7.5 won't exceed idle speed

[MojaveJoe]

Just pulled my J8RCTA out of storage after 8 years. Put it away by simply running it out of gas.

Put some oil in cylinders. Changed the plugs. New gas. Choked. Started on 5th pull.

My problem is...it won't exceed more than 200-300rpm above idle. :face palm: In gear or out of gear.

What should I look for as the problem, and how is it most easily fixed?
Is this a job I should tackle? Im fairly handy with a wrench

Any and all advice and experiences welcome.
Thanx

 

[RadarRick]

Re: '83 Johnson 7.5 won't exceed idle speed

Debris in carb? I would rebuild carb and check/replace fuel lines. 8 years is a long time - rubber lines will deteriorate and lodge in carb passages/jets.

 

[HighTrim]

Re: '83 Johnson 7.5 won't exceed idle speed

There is a thread here you need to read

http://forums.iboats.com/showthread.php?t=158086

 

[MojaveJoe]

Re: '83 Johnson 7.5 won't exceed idle speed

Thanks HighTrim....looks like I have even more work to do to make my Dads old Johnson run as good as when he was alive. :redface:

Rick, I suspect you are right. Guess Im not going to avoid pulling the carb. At least I will be able to fix it from 2 miles offshore if necessary

 

[5150abf]

Re: '83 Johnson 7.5 won't exceed idle speed

Concur, classic dirty carb symptoms, while you are at it change all the fuel lines including the bit under the hood, after so many years it flakes off the inside wall an will constantly plug the carb.

A fuel filter also helps keep the carbs clean, finnaly got one on mine 2 years ago and haven't had a single carb problem since, even the cheapy clear plastic ones are fine.

 

[kbait]

Re: '83 Johnson 7.5 won't exceed idle speed

You especially want to change the line from the pump to the carb. There's nothing to stop the debris from that old hose from gumming up the carb. The intake to the pump has a screen to catch upstream gunk. Make sure that's clean.

 

[kfa4303]

Re: '83 Johnson 7.5 won't exceed idle speed

you may also want to install an inline fuel filter after the fuel pump. You can get one for $2-$3 from any auto parts store and they offer a bit of a window to see if/how your gas is flowing. They look like this (more or less) http://www.aircraftspruce.com/catalog/graphics/05-01030.jpg. I love the extra security they offer and they couldn't be easier to use and install. Just a thought. Good luck.