'89 90hp Merc Carb Problem?

[Joe SixPack]

My '89 90hp has suddenly lost power. She idles fine but when asking for any power not much is coming. I have spark and compression that is very close on all cylinders.<br /> Plugs are all very clean. What is this telling me and how do I check to see which carb or carbs are the offending ones? I took off the air box and got alot of liquid out of there. Ran it with the air box off and nothing coming out of the carbs.

 

[mellowyellow]

Re: '89 90hp Merc Carb Problem?

what kind of liquid? is she bogging down and not<br />getting rpm's up?

 

[Joe SixPack]

Re: '89 90hp Merc Carb Problem?

I have not looked at the R's. Probably going about 5 mph, she is not bogging but the additional throttle just deepens the tone of the motor.<br /> I have now gone out to the motor and the liquid in the airbox I believe now is just the gas from when I raised the engine. I ran it with the airbox off and it did not leak any gas from any of the carbs. I assume this would signify a bad float?<br /> It initially was running fine, I went and landed on a beach, let the kids swim and when I drove away pulling them on their inflatable I noticed that I wasn't getting the power.

 

[mellowyellow]

Re: '89 90hp Merc Carb Problem?

maybe a spun prop hub?

 

[Joe SixPack]

Re: '89 90hp Merc Carb Problem?

I am assuming that a spun hub would be stripped and would'nt this create an overrev condition?

 

[Joe SixPack]

Re: '89 90hp Merc Carb Problem?

After having taken seemingly half the engine apart. Then taking the prop off and marking it I took it to a nearby lake to try. <br /> I trolled out and hit the power---it came right up like in the old days? Tried it a number of times and it is now working fine. It scares me I do not know what I did to fix it. <br /> Mellow Yellow I think it may have been/is the prop hub. I will be getting a backup prop and keep watching the marks on this one. <br /> I searched in the archives for spun hub and that explained what that is. Thank You very much.

 

[Joe SixPack]

Re: '89 90hp Merc Carb Problem?

Back to square one. Wasn't the hub, I have a different prop on now and it is doing it again. At wide open I am turning 3100r's. I just checked the plugs and Number one and three have some oil on them and number 2 is clean as a whistle-how bad is it? What would/could this signify?

 

[LubeDude]

Re: '89 90hp Merc Carb Problem?

Several things come to mind, You need to check the spark on all cylinders while running, also be carefull, if you have a restiction to one of the carbs you could have a lean condition and could score a cylinder or two. Try pumping the bulb while trying to get on plane and see if it makes a difference, if so you need a new fuel pump.