1991 135hp mercury o/b hesatation

rk98

Recruit
Joined
Jul 8, 2009
Messages
4
Hi I have an intermitten problem when I got the boat last year I took it for a test drive when I hit the gas the motor would not excelerate it would bog and not go on plane the dealer rebuilt the carbs [ suposedly] bought the boat as is no warr. well it worked for a while then would do it again then it would clear up. it got worse again I found a leak in the fuel line between second and third carb replaced the line ,ran very good ,till this weekend ran the boat all day no problems when i gassed up the same day pulled away from the dock went about 2 miles then the motor would not go above 1800rpms. when i got back to the dock to take the boat home i tilted the engine when i got home there was gas oil mix in the well not more than an ounce i do not see any leaks when motor is running, the fuel that spilled may of came out a vent , dont know. any way i do not want to tare the carbs apart now. i would think its the gas but a lot of boats gassed up i dont think they had a problem and this is not the first time this happened. i do not have a water fuelseperator am going to put one on .I am familiar with the engine know most of the parts and hoses and were they go and what they do i have a manual from mercury, also like i said the motor runs great when i'm not having this problem also the motor never saw salt water ,and who ever owned it before took real good care of it looks like its only a few years old.
and my gps said i get 46mph out of it . 1990 searay 180 bow rider boat and motor came as a package,any thoughts?
 

flatcat77

Seaman Apprentice
Joined
Jul 31, 2009
Messages
45
Re: 1991 135hp mercury o/b hesatation

check to make sure your gas cap on your tank is venting properly. you might be experiencing a vapor lock issue if your tank gets negative pressure. my uncle had a searay fish and ski that that happened on with a 135.
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: 1991 135hp mercury o/b hesatation

check to make sure your gas cap on your tank is venting properly. you might be experiencing a vapor lock issue if your tank gets negative pressure. my uncle had a searay fish and ski that that happened on with a 135.

From your story, I would lean toward flooding. Maybe a bit of debris in a needle valve, or maybe a float not set right, or leaking. (sunk)

The carbs are quite simple, but need to be set up carefully and accurately.
Gasket kits are about 5 bucks. Base gaskets are about a buck. Get them before you tear into it, but don't be afraid of it.

hope it helps
John
 

rk98

Recruit
Joined
Jul 8, 2009
Messages
4
Re: 1991 135hp mercury o/b hesatation

thanks for your input i will look into it and see
rob:):)
 

wtwe2step

Seaman Apprentice
Joined
Mar 21, 2008
Messages
36
Re: 1991 135hp mercury o/b hesatation

I have the same boat and the same motor and this year I had the same problem. After inspection, I found that many of the fuel and oil lines were cracked and needed replacing. I also rebuild the fuel pump which needed a rebuild after inspection. I recommend you take a close look at all your fuel and oil lines if they are original and replace them if needed and rebuild the fuel pump. The boat is running great now :)
 
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