1999 Johnson 225 ho --- Low Speed Idle Adjustment

[bgiles]

Hi Guys, I have done some searches and found out what to do in this case but just have a couple of questions. Engine has a tough time of idleing after intitial start and after running it a bit.

Motor is 1999 Johnson 225 H.O Carb....Mod #J225HPLEEN

Seems like these engines have a history of idleing challenges, using the search tool found out that the suggestion is to back out the Needle Valve or sometimes referred to as the "low speed mixture adjustment (Allen type of screw with spring) 1 complete turn.

Question ... 1 complete turn seems like quite a bit for a start .. what exactly are we adjusting here ... the amount of air or the amount of fuel ???

Since I am not heading out to the water for a few days I was thinking about simply removing the air box and taking an allen key and backing out each screw 1 complete turn as suggested while it's sitting on the driveway. Seems that Rusty63 is suggesting this based upon experience so why screw around with a little bit at a time.

OR

Should I wait until I'm on the water and maybe do a little bit at a time .. let's say 1/4 turn wait about 30 seconds, do the next one, wait 30 seconds and so on. Once all 6 are done... see how things are. If no good ... keep going with another 1/4 turn. If I go this route is there any particular order that I should follow, top carbs first working down .. side by side ??


I know too many questions ... it just seems that 1 complete turn is an awful lot for an adjustment but if that's what it takes, no problem I'm in and that is why I wondering if I should just go ahead while it's on dry land just to back out each screw 1 turn.

Thanks Guys .. appreciate any feedback


Bruce

[ChampioNman]

You really need the boat in the water with back pressure and up to operating temp. One full turn should do it. You also need to check you idle timing with a timing light and make sure it is set before you start. Then you can adjust each one in at a time if needed.

[bgiles]

Thanks ChampioNman ... I'll wait until I'm on the water in a few days and give it a go. It runs perfectly after the initial few attempts in getting it started but does struggle to idle when you are docking it or sitting in a lock waiting to exit.

Seems like it just needs a little bump to keep her going,


With this adjustment, are we playing with the amount of air or fuel, I just like to know why I'm doing something.

Thanks Again
Bruce

[ChampioNman]

Fuel on jets, air on orifices.

[bgiles]

Thx ......