power loss

[dcook157]

I have a 1990 90HP Johnson. When you start to load the motor there is a loss in power but only for a split second and then it is running fine again. It happens all the way up to and including full throttle where the loss in power is perfectly timed at just under five second. The motor runs and idles fine other than this problem. Any suggestions would be greatly appreciated.

D Cook

 

[HighTrim]

Re: power loss

Welcome to iboats.

The surging definately sounds like your fuel delivery is suffering, but none the less check the spark and compression and ensure all is well before moving ahead. When were the carbs last rebuilt? Sounds as if your bowls are emptying without being filled quickly enough. Could be a couple things.

 

[tashasdaddy]

Re: power loss

agree

 

[dcook157]

Re: power loss

We have checked and there is lots of fuel. The motor doesn't stall or run rough. It's as if the motor has a complete loss of power to all cylinders but clears itself and keeps running. It shakes the whole boat! Also like I mentioned it is perfectly rythmic. If I am on the bottom end of the throttle it happens further apart until it is at full throttle when it is timed out at just under 5 seconds. I decided to try a post to see if anyone has ever seen this kind of trouble because the half dozen mechanics I have spoken to have never seen anything like it.

Thanks in advance for any advice.

D Cook