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ranger73

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i need some help with johnson 90hp (J90PLEEB). last year i unhooked my vro. motor ran good until about a few months ago. it has a bad miss in it now. so i replaced the fuel filter , sparkplugs and hooked the vro back up but still has a miss. i took all the wire plugs apart cleaned them to make sure they were making good a contact. the only thing that i have not changed is the sparkplug wires could that be it? they do have some places that they have been rubbed over the years.
PS: did a compression test today and i have 130 in all 4 cyliners. used 2 differnt gauges to the test and both read 130 in all 4. is that good or bad.
ALSO could i just take the vro off and install a fuel pump if so how? what kind do i need? where can i get one THANKS FOR THE HELP!
 
Hello ranger.
A few quick things I would do. First I would do a spark check. You get to see how well every thing is working, except the plugs.
If that looks good.
get an inductive timing light- hook the wires up to the plugs. Check every wire for a flash on the light. If you have a fouled plug, it won't draw a charge through the coil and plug wire, and the timing light won't light.
if the motor is running for a short while. Feel the temp of each spark plug base. They should all be about the same. if 1 is cold, you have a cylinder that is not firing for some reason.
Watch the engine run while it is dark out. You might see a spark where you should not if you have bad wires.
Look at the burning of fuel on the spark plugs.
I run both my evinrudes with the VRO pump without the oil tank. I mix the oil myself. Works great on both of them.
 
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Do the spark test with the spark plugs removed to obtain the highest possible cranking rpm. Use a spark tester whereas you can set a gap of 7/16" which is required. Let us know what you find.

(Spark Tester - Home Made)
(J. Reeves)

A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.
Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:
　
..........X1..........X2
.................X..(grd)
..........X3..........X4

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay store at:
http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store

Look closely at the stator under the flywheel. If there is a substance leaking, dripping down on the timer base and powerhead, replace the stator. This condition would cause a voltage drop to the powerpack which in turn would result in weak, erratic and eventually no igntion (spark).
 
going work on motor tomorrow could some one post a picture of a spark tester. i have a tester that i use to test for spark on atvs that i work on could i use that or does it have to be one for a boat motor thanks
 
As much as I'm a proponent of the VRO system, once you disconnect it, that's final. You can't trust it again once the oil pump has been run dry for a substantial amount of time. You either need to replace the pump or go back to pre-mixing.
 
im going to stay with the pre-mixing. just need to find out why i got the miss in it. so far with all the testing ive done and checking its looking like it the power pack
 
Parts will be here tomorrow. I was talking to the tech at the shop where I order my parts. He said that I was the reason that the power pack went bad because the way I run my motor. I don't run it at wot I just get it up and let it plane out then I back it back to about 3000 to 3500 rpm and just cruise that about 25 mph. Is that bad for my motor or should I run it wot all the time any info on this would be very helpful thanks
 
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