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paulbip

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40 hp Johnson year 2000 does not have the power to "get out of the hole". I replaced plugs with no difference."
 
"Paul, give us a better descri

"Paul, give us a better description/history of your issue.

Is this something you just encountered this year? Was it working good previously? when? etc.

That will help diagnose the problem - and Matt may well be right, could be something as simple as an incorrect prop selection compared to your set-up - and an OEM prop is usually "not" the best for your situation...."
 
"I have used the engine consid

"I have used the engine considerably since I bought it in 2000. I disconnected the automatic oil injection last year because the plugs were getting fouled and now I add oil by hand. At that time, it would run slow and take a few minuets to get on plane. It seemed to work hard to get over a threshold and then it would increase speed and plane out. It has run fine till now. Same problem.}"
 
"It could well be that you are

"It could well be that you are "over-propped" for your set-up. So, if you are interested, before we try and troubleshoot and engine problem, you can just post the make or model/length of your boat.

I'll throw it all in the prop calculator and see what it spits out.

Too much prop pitch will make the motor "slow out of the hole" and appear to bog until it gets up on plane and up to max rpms.

Do you have a tach connected, and if so, what rpm is it running at when you are wide open???"
 
"I have used this motor and pr

"I have used this motor and prop with no problems since I bought it new in 2000 so I don't see how it could be the prop. It is on a 16ft Sylvan deep v. Before I had this problem, I did notice that when it was running and on plane that I would get a thump like I ran over a floater or something. That only happened a few times."
 
"As always a compression check

"As always a compression check is were trouble shooting starts, no point doing anything else first."
 
"1st - Regardless of what prob

"1st - Regardless of what problem one might encounter, always start with the basic troubleshooting procedure. Check the compression which should be in the range of 100+ psi (somewhat less on the smaller hp engines) and even on all cylinders.

2nd - With the spark plugs removed, rig up some type of spark tester whereas you can set a gap to be jumped. On magneto ignition systems.... and also the Battery Capacitance Ignition system OMC engines from 1968 to 1972, set the gap to 1/4". On the solid state OMC ignition systems from 1973 to the present, set the gap to 7/16". The spark should jump the gap with a strong blue lightning like flame..... a real strong blue snap!

If there was no spark, on engines from 1973 up, disconnect the RED main electrical plug at the engine. Remove the s/plugs. crank the engine via the starter solenoid (jumper bat term to small 3/8" term nut, not the ground nut) and observe spark. If spark is now okay as stated above, the usual cause is a shorted ignition switch.

If the above checks out as it should, and the engine dies out when throttle is applied or won't idle, it is usually due to one or both of two things. The carburetors are fouled, in which case the cure would be to remove, clean, and rebuild them..... or the timer base under the flywheel is sticking which would result in a retarded spark. If the engine will not fire/start at all even though you have the proper spark and compression, it's usually due to fouled carburetors.

To check the timer base for sticking (Engine Not Running), spin the prop to align the shifter dog with forward gear and while doing so, put the engine into forward gear. Now, while watching the timer base, slowly apply throttle clear up to full throttle. The timer base should move smoothly all the way up against the black rubber cap that is atached to the end of the full advance spark setting screw. If the timer base sticks, find out why and correct that problem.

Usually any sticking of the timer base is caused by one of the four retaining clamps being slightly too tight. Putting a very thin washer under the clamp cures that problem. Some boaters use a thin screwdriver to bend the clamp upwards slightly but I prefer the thin washer. The sticking can also be caused by having a faulty stator start to melt down, resulting in a sticky substance dripping down on the timer base nylon retaining ring.

Another thought if you DO NOT trailer that rig, is to check for marine growth on the hull which would create a great amount of resistance."
 
I checked and the compression

I checked and the compression and spark are fine. I did notice some oil that dripped from the prop down the skeg. About 5 drops. This motor ran fine for 6 years and now it lacks power to get out of the hole. I am probly doing less than 10 mph. It is a 2000 Johnson 40 hp.
 
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