25HP Bogs Down - makes my beer spill!

Josey Wales

Cadet
Joined
May 15, 2009
Messages
7
I have a Johnson 25hp (J25TELCCA). Last summer it started bogging down at full throttle. I ran sea foam in gas and it seemed to go away. This spring it's back with a vengeance. Starts great, idles great, I punch throttle and as boat planes out it will bog down/run rough, lose power. I throttle back and it idles fine. Repeat this process 4 or 5 times and suddenly it will take off and run full throttle just fine forever. I stop to fish, and again it takes 4 or 5 or 10 attempts to get it to go full throttle.

I tried pumping ball when it starts to bog down and it does nothing. Hit prime button too, and it does nothing. Fuel pump screen is clean. Gumout in carb didn't help. Sea foam not helping either. It seemed to be real bad last night. Took 10 attempts or so before finally went full throttle. It seems completely random. Any ideas? I read here about a high speed jet and needing a special tool to get at it. I looked at my carb and it appears the starter needs to come off in order to take the carb off? Did they really make it that difficult or am I just slow?

If it was a gummed up high speed jet, wouldn't this happen all the time though? That's what has me thrown for a loop here.

Tnx, JW
 

Trapset

Recruit
Joined
May 10, 2009
Messages
3
Re: 25HP Bogs Down - makes my beer spill!

Have you changed the plugs lately? My '72 Johnson 25 takes J4C's not sure on your '88.
 

CATransplant

Admiral
Joined
Feb 26, 2005
Messages
6,319
Re: 25HP Bogs Down - makes my beer spill!

Crud in the carb. Take it off and clean it properly and install a carb kit. Then, replace all the fuel hoses with alcohol-resistant hoses. Clean your tank.

That it improved with SeaFoam is another indication that it's time for a proper cleaning.

The intermitten nature indicates that crud is circulating in your fuel lines.
 

Josey Wales

Cadet
Joined
May 15, 2009
Messages
7
Re: 25HP Bogs Down - makes my beer spill!

Thanks for the help!

Plugs are new, yes!

Evil crud! I'll snag a carb re-build kit pronto. Looking at the motor last night I was flummoxxed on how to get the carb off. The right mount nut is snug against the starter. Is taking the starter off a big project? Are there any step by steps on line on how to do this on a j25telcca? Looking at the starter I was confused as to which bolts/nuts a guy has to take off to pop it off.

Tnx, JW
 

quackaddict1

Petty Officer 2nd Class
Joined
May 30, 2008
Messages
138
Re: 25HP Bogs Down - makes my beer spill!

To get to my carb on a 28hp Johnson I need to remove the starter to get the carb off. To get mine off requires taking off three bolts. Yours should be similar.
 
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