'97 johnson 175 problem

[croakerpoker]

my engine starts up and runs great when cold. i can run it all day without a hiccup as long as i dont shut it down and let it sit for more than about 20 minutes. after it has been run and it sits, it is hard to start and when it does, it will idle but when i give it gas it will die out. I can sometimes rev it up in neutral but in gear if i give it gas it just dies out as soon as it tries to get above idle speed. i rebuilt the carbs but that did nothing. Any suggestions? it seems like something is getting hot while sitting but i have no idea what?
thank you in advance for any help.

 

[tashasdaddy]

Re: '97 johnson 175 problem

try bumping you key in when it starts to die, see if it will pick up. this will engage the primer solenoid, giving the motor a squirt of fuel directly into the intake, it the motor picks up you have a fuel delivery problem.

 

[croakerpoker]

Re: '97 johnson 175 problem

thank you for the reply
bumping the key seems to make it cut out even faster, like it floods it. i replaced the VRO a couple of months ago because it was leaking oil but this problem has been around since before that. one interesting thing- the hotter it is outside, the worse the problem is.

 

[HighTrim]

Re: '97 johnson 175 problem

You are describing the classic symptoms of heat soak. Pay attention to Seahorses comments in the following thread.

http://forums.iboats.com/showthread.php?t=232431

 

[croakerpoker]

Re: '97 johnson 175 problem

hightrim,
i read that post so to test it i ran the boat and let it sit with the cap off on a cool cloudy day with the wind blowing. i figured that would cool everything off. after sitting like that for 40 min i started it and the problem was still there. idles fine, push the throttle up and at about 900 rpm its runs rough and cuts off.
any chance this could be an electrical component getting hot? stator heating up? i'm stumped.

 

[mboy]

Re: '97 johnson 175 problem

I had VERY similar problem last year on my new to me 2003 175 looper.

Happened at least once a trip.
In Aug I did a DUNK decarb (modified by putting seafoam directly with seafoam).

Havenot had the problem resurface since that.

Not once. She fires right up, every time!

 

[HighTrim]

Re: '97 johnson 175 problem

Try checking the spark once warm, or use a hairdryer in the driveway to heat the ignition compontents, then check for spark.

Let us know what you find.

 

[croakerpoker]

Re: '97 johnson 175 problem

thank you for the responses.
mboy, i totally rebuilt the carbs so i dont think thats it.
hightrim, good idea, i'll try that today.