25hp Johnson woes

[mikesim]

My son has a '00-'01 Johnson 25hp outboard that is acting up. Ity doesn't want to idle well and appears to be misfiring. When you get the boat on plane with WOT it has a slight power loss. You can get the engine to increase RPM's by about 500 or so by slightly pulling out the choke knob. I pulled the cap off and didn't see anything obvious. I did discover however that it doesn't have a conventional butterfly type choke in the carb bore but instead uses some type of enrichment solenoid. Can anyone steer me in the right direction? Many thanks!

Mike

 

[k4ubr]

Re: 25hp Johnson woes

how long has the motor sit up, how about the fuel? (old) ?

 

[mikesim]

Re: 25hp Johnson woes

It had about 3 gal of last years fuel to which we added 3 gal of fresh and a can of Seafoam. I don't think fuel is the issue since the engine ran OK when first used this year. It just acted up on a recent trip this weekend. Tx for yr reply.

Mike

 

[tashasdaddy]

Re: 25hp Johnson woes

you have a fuel restiction. the knob is called a primer, when you pull it out, it pumps fuel directly into the intake manifold, enriching the fuel/air mixture for cold starting. so when you pull it out, you are giving the motor a little squirt of fuel.

did you follow the carb steps in the TOP SECRET FILE > http://forums.iboats.com/showthread.php?t=299680 and use a rebuild kit?

 

[k4ubr]

Re: 25hp Johnson woes

justa note 3 gals of old gas and 3gals. new and you still have lastyears gas.

 

[mikesim]

Re: 25hp Johnson woes

All good points! I think I will dump out the old fuel, replace with fresh, add a can of Seafoam and clean the fuel filter and spark plugs and give 'er a shot. I ordered a service manual today so I will have a better understanding of how the fuel enrichment system works. I'll report back.

Many Thanks!

Mike