Boat motor problem, need help

[3GIRLSDAD]

I need yall's help. I've got a 74 model Johnson 25 hp. Has been running real good up until a couple weeks ago. One day it ran like a top, the next day ran like a 5 horse. In neutral it will turn the rpms up but in gear it won't. And wide open it seems about like 1/4 throttle and every now and then sputters like it is trying to come to life. I have checked the plugs, both giving fire, checked the fuel filter its clean, getting gas and sending gas to the carb. Linkage is advancing all the way, and I sprayed carb cleaner in the carb. Didn't help a bit. Anybody got any ideas? Hate to spend 60 bucks an hour for a mechanic. If it was 20 I wouildn't mind, but 60 is hwy robbery. Somebody help a poor boy out.Thanks

3Gd

[Billbob]

does it have points???

[CrappieHound]

I've got a 9.9 Johnson and yesterday it did the same thing you decribed. I fiddled around with it four an hour on the lake. Come to find out the choke was pushed all the way in. I pulled it out halway and...wallah! she came to life. Try messing with your choke...sounds like that is the problem.

Hope this helps.

[skleppe]

Just had the same problem to a 1977 35HP Evinrude. The high thottle passage in the carb was the culprit. Rebuilt the carb and it purrs like a kitten under load. The carbs are easy to do, not much to them.

[Barnacle Bill]

That spray carb cleaner does nothing for a carb except to clean the throats. You might try running a can of Sea Foam thru it. Most auto parts stores carry it now. That is really some fantastic stuff.

[slabbatical]

You didn't comment on your fuel tank and fuel line. I'd also check those. If any of the connections to the motor/from the tank are old and even a little cracked, I'd replace them. This is easy with a external tank. If they are not able to hold a seal, you won't get good flow to the motor and all the other places you already checked.

Good Luck.

PS (I learned this the hard way)...If you replace a fuel line, make sure you install it according to the arrow on the bulb. The bulb only allows gas to flow one way. I caught the error pretty quick but I still felt pretty dumb.

[bentpole]

Good advice slabbatical,Als o check & see if the bulb from the tank is sucked in flat.I've seen them do that.While you are running the motor pull out on the choke alittle at a time,If it seems to help with the chock out then it's almost a sure bet that the Carb's are trying to clog up.

[gabowman]

If you aint found the problem yet look for the high speed (air) jet on the outside of the carb. I was missing the low speed jet and mine did right the opposite. At low speed it sounded like it was gonna choke down. (Mine's a 2 cyclinder 50 hp and sounded like it was running off 1 cyclinder.) At high speed it did fine. On mine, the (air) jets are on the side of the carbs. I was looking and seen what looked like a screw missing on the top/side portion of the carb. The one under it had a brass like bushing in the screw hole so I knew then what was missing. Good luck straightening it out.

[sccamper]

Does your carb have 2 air/fuel adjusters? My '72 20hp johnson has an idle adjuster and a cruise adjuster. I was told mine had to be adjusted w/ temp changes ect., but Ive found a where it likes to run and I dont mess with it. It does run bad if out of adj. I also have a problem at times not wanting to get going and plain out ; I think it gets stale gas in the bowl. You might check your gas.

[Matt Smith]

Do Not Use Carb Cleaner On A Two Stroke Carburetor!!!