Mercury 125HP Performance- Need Help

[imported_ryno]

I've done some searches through the forum, but couldn't find the info I hoped for. This site has always been a phenomenal source of info, and I've solved many problems right here!

I just bought a new/used boat. Its a 1998 Tracker Targa with 2-stroke Merc 125HP. Its well taken care of, has less than 100 hrs, and appears to be in great shape. The only problem is the guy I bought it from, didn't use it for the last 1.5 yrs! He left about 8 gal. in the main tank, but indicated that it was Stabilzed.

Upon bringing it home, I went through and checked out all the systems. Good. I added another 8 gal. of fuel, along with a bottle of Heet, to dilute the old gas. Surprisingly the boat started in about 5 seconds and never stalled. It runs great at idle and low rpms. Unfortunately, it hesitates under load, like coming out of the hole and at top speed. It currently tops out at 33 mph at about 4700 rpms with about 90% throttle. The owner indicated that he got 37 mph at about 5200 rpms at full throttle. When I give it the full throttle, it actually bogs back down. I've cleaned the plugs and they looked good. I am going to go ahead and order some new plugs and an in-line fuel filter, and run out this "old" tank of gas. I wanted to see if there is anything else I can do before putting into a shop. There has been some reference to Sea Foam products. Would that help in this case? Thanks for any insight any of you may have!

 

[tashasdaddy]

Re: Mercury 125HP Performance- Need Help

sat for 1 1/2 years with gas in the carbs. they are probably gummed up. i would think about and impeller also, as the dry out, when not used, and tend to fail, on the cold rainy, windy,rough day. i have started my engine on muffs at home, and gotten to the ramp and the impeller not pump.

 

[Laddies]

Re: Mercury 125HP Performance- Need Help

Take the time and clean the carbs, running it around lean can damage a piston

 

[imported_ryno]

Re: Mercury 125HP Performance- Need Help

What would you recommend for the cleaning process? I talked with a mechanic today, and he said I should rebuild the carbs, that any of the solvent cleaning processes would just be a temporary "bandaid". Yeah, thats $300 I would have to dig-up, after spending all that coin on a boat!

 

[jddenham]

Re: Mercury 125HP Performance- Need Help

There's nothing cheap about owning a boat!

If you can buy a manual and learn how to do routine service work like rebuilding carbs you will save a lot of money.

Have fun.

 

[JasonJ]

Re: Mercury 125HP Performance- Need Help

I would run that old gas through, change the water pump impeller because it can take a "set" and not pump as efficiently. The motor did not sit long enough for the carbs to gum up. Gas evaporates out of carbs quite quickly. Usually what gums up a 2 stroke outboard is premix that has had the gas evaporate, leaving the oil to fester in the carb. I am assuming your 2 stroke is oil injected. If so, there should not have been any oil festering in the carb. You did not say if he had used any fogging oil or do any storage prep to the motor. The fact that your motor is not performing like the previous owner stated does not necessarily mean its not performing properly. He may have ran the setup differently. Trim position, load, it all makes a difference.

Also, you should not use HEET, it says right on the bottle not for use in 2 stroke engines if I remember rightly. Seafoam is a better additive, as it removes water and is 2 stroke compatable. Buy new spark plugs. They are cheap, and just looking at a plug doesn't mean the plug is good. Like I said before, get rid of all the old gas, then run it on all fresh gas, and then go from there if the problem persists. Good luck.

 

[MortenH]

Re: Mercury 125HP Performance- Need Help

Rebuild the carbs - easy if you have the manual. If not, buy one. As for running the old fuel - I would not have done it. Also get a new fuel line and primer bulb. And maybe rebuild the fuelpump as you are in it The stalling at full throttle can easy be lack of fuel, and running lean can cost you a lot of money and work, trust me, I've been there:'(

-M-