'92 40 hp Johnson won't run well in gear ?

[DrinkingEmu]

1st year of boating, many questions, not sure of part names.<br />'92 40 hp Johnson model TJ40ELENM on 17 ft aluminum.<br />boat in lake:<br />In N I can throttle and get high rpms (5000+) <br />In R I can throttle go backwards and get high rpms (5000 +)<br />In F the motor bogs down and will not climb rpms<br />only reaches 2500???? WOT should be ~ 5000<br />Motor feels ok untill throttle is pushed, then it feels and sounds like it is really struggling???<br />I should add:<br />New fuel<br />new plugs<br />new fuel line with ball<br />seafoam decarb'd(followed directions under search)<br />new fuel filter<br />new plugs<br />All to try and eliminate this. Any other ideas? Please

 

[DrinkingEmu]

Re: '92 40 hp Johnson won't run well in gear ?

Drove to marina today to try and get Seloc manual, they did not have 1 for my year. So I have ordered it

 

[tashasdaddy]

Re: '92 40 hp Johnson won't run well in gear ?

#1 you shouldn't be running that high in neutral, and why in reverse. have you tried pumping the fuel bulb when it is acting up. how old is the fuel? how long has this engine sat up? what have you done to it? what's it's history?

 

[javsam]

Re: '92 40 hp Johnson won't run well in gear ?

yes,you can blow the motor taking the rpms over 2000 without a load(in Neutral). do you have an owners manaul? if not get one and read it.<br />javsam

 

[NIGHTFISH]

Re: '92 40 hp Johnson won't run well in gear ?

All the above is true. One thing you need to do is chek compression. Always a good start. If a piston is fried it will not perform under a load. I would try that first to prevent further damage if it turns out to be low or no compression. If you keep trying to run the engine with a scarred piston you will do nothing but make things worse and potentially sling a rod. Then the motor is pretty much useless after that. If you have a problem dont run it any more than you have to until you have identified your problem. If that is a go, try fuel and fire. Make sure that you are getting good spark from each plug. Make sure you are getting fuel to required areas of your outboard. 3 things to make the boat run is fuel, air, and fire. If it is not compression my guess is you have one of these complications. The manual should help you out alot.

 

[DrinkingEmu]

Re: '92 40 hp Johnson won't run well in gear ?

Hi thanks for response, I put down the symptom of runs ok in N and R, but not F as I thought it would indicate something. I would not run the motor at that range. Just that the RPMs climb freely in those transmission postitions.<br />Bought boat used in middle of winter. Only saw it run with muffs cycling antifreeze through in a bucket with pump putting anti freeze to muffs<br />--Compression 120 top cyl 118 bottom cyl.<br />--fuel bulb is hard and when pressed doesn't change the running<br />--pushed key in(to squirt primer) when engine struggling no change<br />--took off cowling watched clear fuel filter( it is before vro pump) at idle it is ~1/2 full<br />--fuel filter looks empty when I push throttle, then fills back up. Normal?<br />-- motor ran fine first thing in am,fished with electric for 2-3 hrs. then struggled<br />--I will try the spark plug check next, other ideas