Johnson 90 low power problem

[vjb]

I have a 1989 Johnson 90hp with very low hours. It starts and idles fine but when I go past about 1/2 throttle it bogs down and I cannot get any more power unless I hit the push button choke. As long as I hold down the choke it screems and I have full power. I don't do it for long. After doing this several time over for about 30 minutes the engine seems to run OK. Does it sound like a dirty carb or VRO problem or what?

 

[ob]

Re: Johnson 90 low power problem

Well if it was a dirty or fouled carb I wouldn't think it was just clear itself.So for now I'm ruling that out.Does this engine have the T/stats installed?Have you inspected the carburetor to manifold gaskets for any air leaks or loose bolts?

 

[vjb]

Re: Johnson 90 low power problem

Thanks ob. I brought the boat into the garage last fall to work on it over the winter. I did notice quite a bit 2 stroke oil in the engine cowling and boat engine well (Whaler Montauk). I haven't yet checked any of the bolts or hoses to the pump/carb but I will tonight. What are a T/stats?

 

[ob]

Re: Johnson 90 low power problem

Thermostats.Sometimes owners will remove them.This can cause very slow warmups.Yours sounds leak related.I think you're on the right track to insure all fuel hoses are leak free and the carb base gaskets are sealing.Also insure that the fuel tank is venting properly.<br /><br />BTW- Nice boat and welcome to iboats.

 

[vjb]

Re: Johnson 90 low power problem

I don't know for sure. I bought a thermostat kit last weekend to replace them so I'll find out if they were removed.