2000 Johnson no power in gear

[johnson_stx]

Yesterday after doing about an hours worth of wakeboarding one of my engines would not stay at idle and/or increase in rpms when in gear. If i put the enfine in neutral and give it gas (throttle down) the rpms go up like normal but once in gear (either forward or reverse) it stalls or doesn't go any faster than 1200rpms. I tested the compression on all six cylinders and all are about 110 psi. i notice that the carbs opening (where the air silencer goes) is a little wet (gas/oil mixture) also if i cover the opening on any of the carbs it stalls the engine. Since day one this particular engine has always had poor idle when warm but once in gear and over 1000 rpms it performs well. Any ideas where i can start troublshooting?????

 

[JB]

Re: 2000 Johnson no power in gear

Howdy, Johnson_stx.<br /><br />Welcome to iboats. <br /><br />Sounds like you have lost power from half your cylinders.<br /><br />Check them all for spark.<br /><br />It would help us a lot to have the model number, etc. of the offending engine.

 

[johnson_stx]

Re: 2000 Johnson no power in gear

thanks for reply JB. Once get home i will send you the model of the problem engine. out of curiosity what would becausing the lack of spark if that is in deed the problem? Several years ago i used to use a gel-cel "maintance free" battery and was blowning power packs on this engine about every three months. the problem that experienced then was almost like the engine was mis-firing at just about any speed. after switching the battery to the other engine the same thing happened so i got rid of it an now just use regular type battery. Also, do you know why the engine would rev in neutral and not when throttling down in gear?

 

[JB]

Re: 2000 Johnson no power in gear

Those engines will rev like crazy on 2 cylinders when there is no load on them, JS. Sometimes they even start and idle as though they have full power available.<br /><br />Powewr pack is a good suspect, depending on what engine you have.

 

[johnson_stx]

Re: 2000 Johnson no power in gear

JB,<br />The model number is J175VCXSS. I just swapped power pack, coils, and cables from one engine to the other. the engine seemed to run a little less rough but that could be from it being warm already. i did notice that (even though they say not to put the motor in gear out of the water when i brought it back to neutral the rpms went up a little then back down to about 850 (idle). unfortunately the true test will be in water. is there anything else i can try before launching it to test it out?

 

[Walker]

Re: 2000 Johnson no power in gear

You could have just checked for spark on all cylinders before you swapped all the components. <br />Check you fuel filter for obstruction. Is your alarm system functional?

 

[johnson_stx]

Re: 2000 Johnson no power in gear

Fuel/water seperator, filter all clean. I can see that fuel is entering the engine. One thing that i did notice was the fact that when the engine is on and oi manually move the carburetor linkage arm (device that open and closes flapper inside carb) the engine chokes and shuts off. If i do this on my other engine it simply revs up in rpms. have any idea what this means?

 

[Walker]

Re: 2000 Johnson no power in gear

Okay, make sure your timer base is moving forward when you move the throttle. You can do this without the motor running.

 

[johnson_stx]

Re: 2000 Johnson no power in gear

what do you mean by timer base? Are you taking about the optical timing sensor (OIS2000), if so then yes the sensor moves as i throttle up. However, if engine is in neutral and i manualy move the linkage arm to open the flappers inside the carbs the engine chokes and shuts off. this result is totally different on my other engine. if i do the same on my "good" engine it revs up like its supposed to. Any ideas?