Johnson 2000 50hp cuts completly at WOT

[chris abela]

Hi to all. After 5 years of fun boating I have now got a problem with my engine. It runs fine when trolling and not going over 3000rpm but when it comes to running back home it runs for a few minuits and then cuts out completly as if you pulled the safety cord by the key. It would then start at once after I turn the key. We got home on low revs. The possible causes I thought were that the SLOW function was kicking in, cause I felt the tell tail water a bit hot, but is'nt the slow suppose to reduce the revs not completly cut the motor. There are no warning buzzes or lights and all work on startup.<br />Ive checked the impeller and the thermostat and nothing seems to be blocking the passages. I have also grounded the tan colour wire to check that the warning light works. One thing thats funny is that usually a lot of oil comes out of the propellor when in the garage as I rinse the motor on a winterizing mix every time its used. This time there was no oil whatsoever. Another thing is that I have just changed the battery, and the last time out I forgot to undo the breather on the tank and used about ten litres of fuel which made the tank sort of implode.<br />I'd appreciate any comments keep up the good work.

 

[chris abela]

Re: Johnson 2000 50hp cuts completly at WOT

anybody?? please

 

[ob15]

Re: Johnson 2000 50hp cuts completly at WOT

Next time you're out & the motor acts up push in the key & see if motor picks up. If so, you propably need to clean your carbs. When was the last time the carbs were cleaned? Are you using a fuelfilter/water separator?

 

[clanton]

Re: Johnson 2000 50hp cuts completly at WOT

Remove the starter check the pulse hose to the fuel pump, the starter rubs a hole in the hose.

 

[chris abela]

Re: Johnson 2000 50hp cuts completly at WOT

thanks for the replies<br />dave the ccarbs have never been cleaned, but i spent two hours trolling at 2000 rpm, and it went goes fine at wot for about 5 minuits<br /><br />clanton, i checked that three years ago i think i read it somewere elce

 

[umblecumbuz]

Re: Johnson 2000 50hp cuts completly at WOT

Hi Chris,<br /><br />You said:<br />

... cause I felt the tell tail water a bit hot ... One thing thats funny is that usually a lot of oil comes out of the propellor when in the garage as I rinse the motor on a winterizing mix every time its used. This time there was no oil whatsoever ... last time out I forgot to undo the breather on the tank and used about ten litres of fuel which made the tank sort of implode.

Just thinking about these three statements, and assuming that your problem started at the same time as these symptoms showed up, this is a long shot:<br /><br />It is just possible that the tank 'implosion' pulled some impurities into the fuel line that have caused the carbs to run lean without cutting off fuel completely. Over-lean running at WOT would cause the motor to run hot, as you've noticed, and after several minutes might cause the carbs to lose fuel sufficient to cut out the motor. Lean/Hot running would also reduce the unburnt fuel/oil mix that often comes out through the prop when the motor is shut off.<br /><br />I'm based in Mosta, and usually launch at the il-Veccia end of St Paul's Bay. Whereabouts are you?

 

[chris abela]

Re: Johnson 2000 50hp cuts completly at WOT

hi ensign imm in ibragg and i launch anywere thats calmer.<br />Thanks for the input but the only thing i can think of is that the water pump needs changing. The impellor looks brand new and i think its a shame to change.<br />Ill just have to start by elimination. <br /><br />Still does anybody know if the SLOW sysetm slows down or cuts the engine?

 

[ob15]

Re: Johnson 2000 50hp cuts completly at WOT

The slow system does exactly as is says, its limits rpm to 2000. I would clean the carbs. You never mentioned if you have a filter. If not, You could have a bunch of junk in the high speed jets. Not having the carbs cleaned for 5 years kind of suggests that could be the problem.<br /><br />Over heating doesn't sounds like the problem.<br /><br />When flushing the motor in your driveway you will get some unburnt fuel oil out of the exhuast. Just the nature of the beast.<br /><br />Edit<br /><br />Might as well change the water pump & thermostat if that hasn't been done in 5 years also.

 

[Solittle]

Re: Johnson 2000 50hp cuts completly at WOT

chris - You can't tell the servicability of the water pump by looking at the impeller. They develop a "set" & need to be replaced periodically.

 

[chris abela]

Re: Johnson 2000 50hp cuts completly at WOT

thanks solittle ill start from there and see by elimination

 

[chris abela]

Re: Johnson 2000 50hp cuts completly at WOT

just to give you my results, the fuel line to one carburator was holed, maybe by whoever stuck it on originally. this i presume was creating a lean condition in one cylinder causing it to overheat.<br />Problem solved I hope thanks to everybody