Johnson j25balcnb dies when opening throttle

[saffi]

I recently bought a johnson 25 HP (j25balcnb, s/n b01677). It starts well and runs idle. When you open the throttle it dies. Checked the carb and it is clean and looks fine. Still everything points to a fuel problem. I was wondering if someone could post the timing, carb float (sorry, I'm dutch and don't know the word) and Spark specs. What manual would be best to buy? It ran "ok" for a while and started running not so well after 10 or fifteen minutes. I checked everything in the fuel system and there's no problem there. Sparks plugs are OK and fire well but I want to replace them. I can only think of Timing or possibly the distance between the needle and the float in the carb but need specs for that. Thanx, Lucas

 

[The Marine Doctor]

Re: Johnson j25balcnb dies when opening throttle

If the engine ran for 10-15 minutes then started giving you trouble, I would think that maybe one of your ignition coils dropped out on you.<br /><br />Some engines will survive off idle on 1 cyl while some others just die.<br /><br />TMD

 

[Joe Reeves]

Re: Johnson j25balcnb dies when opening throttle

Saffi.... In cleaning the carburetor, did you actually clean the brass fixed high speed jet that is located in the bottom center portion of the float chamber? If not, that may very well be the cause of your problem. Clean it manually, then blow it out.

 

[saffi]

Re: Johnson j25balcnb dies when opening throttle

I'll have a look at it again. I don't think the coil is the problem as the engine can still revv when I squirt in some fuel from the front (that's why I think the carb is the problem) I'm getting a bit confused now. The brass fixed high speed jet is attached to the top (I think). There's a small "tube" with some openings going to the top and the "inner tube" is not really centered. This caught my attention. Judging from the green "rash" I think there has been some water in the float chamber. I'm reluctant to open this "inner tube" going up as I don't know if it will come loose easily and I'm scared to break it. Where would I find the manual? Iboats does not ship overseas and will the US version of the book cover my "belgian" engine? I read a post on an identical engine.. the one with the "bung??".<br /><br />The Light plug on the side. Does that give alternating current?? I also would like to charge my battery with it. (Convertor/stabilizer??)<br /><br />Thnx

 

[Joe Reeves]

Re: Johnson j25balcnb dies when opening throttle

I told you exactly where the brass fixed high speed jet is. Remove the 7/16" hex bolt from the front of the float chamber, stick a wire in there and clean it.

 

[Solittle]

Re: Johnson j25balcnb dies when opening throttle

saffi - Your reading assignment is:<br /><br /> http://www.outboardrepairs.com/carburetors/

 

[Mucka29]

Re: Johnson j25balcnb dies when opening throttle

hey,<br /><br /> before you tare your motor apart, drain your float bowl and get new fuel, water in fuel might be problim

 

[saffi]

Re: Johnson j25balcnb dies when opening throttle

Thanks Mr Reeves, I didn't know the high speed jet was there. There was some dirt and probably oil residu in there. Blew it out with compressed air and cleaned it. I also had to ajust the heigt of the float (they said 19.4 MM at the shop) The engine was probably stored for a long time before I got it. Got new spark plugs and found an adress with a spare carburator if I would ever need one. Is it true that one can make a 25HP into a 35HP by just changing the carburator? The engine runs very well now and idles smoother. Timing seems OK. It keeps smoking a bit though but I will get into that later. Thanks for the help.