johnson experts, need help

[tendollar]

1998 Johnson 150 Put it in the water today, fired right up, 5400 rpm 49.1 gps behind a 196 crestliner. Shut it down for awhile, fires right up but doesnt want to stay running, almost seems like its starving for fuel, farting back through the carbs. If I hurry it into gear and get after it it will go, but just putting around watching the sonar it starts acting up again, any ideas?

Tom

 

[jonesg]

Re: johnson experts, need help

1998 Johnson 150 Put it in the water today, fired right up, 5400 rpm 49.1 gps behind a 196 crestliner. Shut it down for awhile, fires right up but doesnt want to stay running, almost seems like its starving for fuel, farting back through the carbs. If I hurry it into gear and get after it it will go, but just putting around watching the sonar it starts acting up again, any ideas?

Tom

I'd agree, starving for fuel.
Rebuild the carbs, iBoats carries the carb kits ($22 ea),
its an easy DIY job in a couple of hours first time round.
Got a water seperator?
Fresh fuel? with additive such as startron or whatever.
49 mph is quick.!

 

[tendollar]

Re: johnson experts, need help

been searching this issue on here and it seems nobody ever lists a solution. Was also thinking carb job, alot of grime inside that airbox. Fresh gas, 2+4, carbonguard and 4hr soak with tuner. It is a quick little boat, that johnson really runs good w o t. I do not have a seporater

 

[tendollar]

Re: johnson experts, need help

Had the boat out to the lake today, right off the trailer motor runs perfect no issue at all, idles perfect, right up on plane and goes. Back off plane putting around runs perfect, shut down for awhile and try to start back up symptoms start, fires right up, starts to cough and dies, cranks right back up idles, coughs and dies. Give it some throttle and it sometimes will cough and stumble but seems to clean up and goes. Posting this again because I have done a ton of searching on this subject and it seems like the common denominator is this "heat soak" issue and i wanted to run the boat again to pay close attention to the problem. I definitly have not ruled out rebuilding the carbs but would like to find out more about this "heat soak" problem and if there is a fix for this?

Tom

 

[jonesg]

Re: johnson experts, need help

To confirm heat soak remove the hood when you stop and fish a while.

One fix I read is to let it idle a while before shutting it down, the block will cool down. And try pumping the bulb before firing up, it will fill the bowls with cold fuel and reduce fuel vaporizing.