1994 125 Merc Wont Idle

[tonydl86]

I Have A 1994 125 Hp Mercury That Was Stored For About A Year. I Started It Occationaly But Last Weekend I Finaly Took It Out. Almost Imediatly I Started Having Trouble Runing It At Idle, Then It Would Not Run At All Unless I Ran It On High. After A While I Could'nt Even Start It Normaly Because It Would Not Run On Nutral. I'd Have To Choke It To Start, And As Soon As It Started Take The Choke Off And Gun It And Once On High It Would Go Very Nice Like Nothing Was Wrong. I Know That This Engine Runs On Two Pistons At Idle, Well I Think Anyway,but It Never Acted Like This Before. I'm Told That The Carbs Might Be Clogged, And That I Should Get Rid Of The Gas In The Tank (whitch By The Way, Was Half Full While Stored And Topped Off Before Going To The Lake ), And Have The Carbs Serviced. Before I Do This Is There Anything That I Can Do to try and clean the system Without Taking The Carburator Apart.

 

[jeffl78]

Re: 1994 125 Merc Wont Idle

You can try running a bit of carb clean through the barells while the motor is running and throttle open considerablly. A freind of mine is a master ASE and he suggests silicon spray like wd-40 instead because it won't harm any seals and instead conditions them. If the carbs seals are old this is what I would reccomend. Regardless, it sounds like you should go through the carbs anyway, as I bet the haven't been done in a few years. Rememder, it could be the fuel pumps or somthing else. I don't think it's that needed in your case, but I aways start with a compression test before I put any money into trying to repair a motor. You'd be suprised what kind of runnablity problems just seem like fuel problems turn out to me bad rings and, our cylinders, head gaskets, ect. I do not think you have this problem because your motor runs great @ WOT.

 

[tonydl86]

Re: 1994 125 Merc Wont Idle

Thanks For The Feedback, I Guess I'll Probably Wind Up Taking It To The Shop. What I Was Wondering Before I Do, Is There Some Additives Out There That I Can Mix With The Gasoline Like The Ones You Use In Your Car To Clean Out Injectors And Such That I Could Try. There Is Some Stuff For Cars That Work Exellent, Maybe There Is Something That Works As Well For 2 Cycle Engines. ?

 

[hkeiner]

Re: 1994 125 Merc Wont Idle

It is better to clean the carbs by taking them off the motor and cleaning them in carb cleaner. However, cleaning the carbs with Seafoam is worth a try as an alternative. It is easy to do and inexpensive. It might work in your situation or it might not. It is worth a try as it worked for me when I had a similar problem with my carbs.

There are many threads on the use of Seafoam to deal with dirty carbs. My preferred method is to use a high concentration of Seafoam with a portable 3 gallon tank. Mix two cans of Seafoam with 2 gallons of gas in the portable tank. Connect the portable tank to the motor, idle the motor for 5-10 minutes, and then turn it off for 15-30 minutes. Repeat until the Seafoam mix is used up. Letting the motor sit overnight with the Seafoam mix in the carbs is good too. After the Seafoam mix is used up, run the motor with just regular gas in the portable tank and see if there is an improvement. You might need to use a second batch of Seafoam mix to get results. This process will also decarb you motor as a side benefit.

If you try the above method and it helps, report back for the benefit of others with similar problems.

 

[KRS62]

Re: 1994 125 Merc Wont Idle

I am having the same problems with my '84 75HP Merc. It sat for many years and then my Dad gave it to me to use. It was "useable" during duck hunting season, but when I took it out yesterday, it was a pain in the rear. I went through 2 batteries since I had to crank it so much (and was almost stranded!) It runs great once up on a plane, but would not idle worth a darn. Keeping the fuel line ball pumped up seemed to help, but who knows if it really did.

I use Seafoam in my vehicles and I think I ran a can through the boat when I first got the boat, but I am not sure. I will certainly try it again, but just started searching this forum today for a resolution to this problem! I would love to get the boat running as good as it used to. I hope to hear if you get yours fixed.

KRS

 

[hkeiner]

Re: 1994 125 Merc Wont Idle

If pumping the fuel bulb helps, that could be a sign that your fuel pump is not working well and needs to be rebuilt. It could also mean that you have an air leak in the fuel line somewhere.

Using Seafoam at a HIGH concentration (1 can per gallon of fuel) is more likely to be effective than using it at the NORMAL concentration (1 can per 20 gallons of fuel) as a possible solution for a dirty carb and such. Using a small portable external tank is used so that you don't have to make many gallons of this high concentration. Of course, removing the carbs and cleaning them properly is the best way to go.