1995 Force 90HP lost power?

[Rayski]

I have 1995 Force 90HP that up until last week ran great. I have it mounted on a 2002 Key West 1720 DC that usually runs about 37 to 38 mph @ 5000 rpms. Last week I had just got underway at full throttle when the motor hesitated and the speed dropped to about 32 mph and the rpms went to 4000. It never cut off and it ran like this the rest of the time on the water. When giving it full throttle it feels really sluggish and takes longer than usual to power up to full speed. After that day I replaced the spark plugs, which looked fouled and took it back out. Same problem, sluggish and not reaching the previous top speed, but started and ran fine, just sluggish. Thinking that it might be the fuel, I checked the primer bulb and fuel hook up for any build up that might be restricting flow and found none. I replaced the fuel filter and brought along an external tank with fresh mixed fuel 50 to 1. I started out on the external tank and the top speed went up to around 34 mph and the rpms went to 4200 but still sluggish and not running near the original 38 mph and 5000 rpms. I went back to the internal tank and the performance was the same. This makes me think it is not the fuel. I am not sure what to do next? I do not feel good about looking into the carbs. Any suggestions or help would be greatly appreciated.

 

[roadrunnr]

Re: 1995 Force 90HP lost power?

Compression test first. All three cylinders should be within 10 percent of each other and all above 100 psi. If compression checks out, you may have a weak or torn fuel pump diaphram. These are easy and inexpensive to replace. If you post your outboards serial and model numbers, the guys on this forum can direct you to the right parts, which can often times be purchased right here on iboats. Good luck and let us know what you find out!

 

[Rayski]

Re: 1995 Force 90HP lost power?

Roadrunnr,

Thanks for the reply. I will try this next and post the results. Thank you again!

 

[Nate3172]

Re: 1995 Force 90HP lost power?

Check your fuel pump. Sounds like fuel starvation to me. May also want to make sure that the float bowls on the carbs don't have any gunk in them.

 

[Frank Acampora]

Re: 1995 Force 90HP lost power?

Oooh--Oooh--Oooh! You just hurt the most sensitive part of my brain. Why, oh why, if you were having trouble with the engine did you insist on continuing to run it at full throttle thereby compounding the chance of incurring or increasing any possible damage?

First major inviolable rule of outboards: If you are having trouble, slow it down! --Or do not run it until problem is found and corrected.

Like roadrunner told you, check compression and check the fuel pump. If compression and fuel pump check out OK, like it or not, you are going to need to remove at least the carb fuel bowls and check for goo in there. If you have mixed different brands of gasoline in the same tank, there is a possibility that you have mixed different additives leading to a jello like substance forming and clogging the carbs. Out of the presence of gasoline, this substance drys out and looks a lot like sand. So, if the carb bowls are empty and you see a gritty substance in them--or anything at all-- Take everything apart and clean well.

 

[Rayski]

Re: 1995 Force 90HP lost power?

Frank,

I hear you, I guess I figured that if it was fuel related it would clear itself up. I didn't run it full throttle after I knew it wasn't going to fix itself. If you are not sure what is causing the problem, and you make some adjustments, how are you going to check it out if you don't try to run it at full throttle? I appreciate all the help. I bought a compression tester this morning so I will try this first and then go from there. Thanks again!

 

[JPvancleave2258]

Re: 1995 Force 90HP lost power?

Hey, Did you ever figure out the problem? I am having the same problem.

 

[Bob_VT]

Re: 1995 Force 90HP lost power?

I highly doubt you will get an answer in this thread that is over 2 1/2 years old.

Welcome to iboats. This was a thread from the archives and we really just use them for reference.

I see you posted and started a new thread so. this one will be closed.