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2002 johnson 90hp 2 stroke ..j90plsnf..tilt trim

joek

Member
hello there..i have a problem with my powr tilt trim putting a big draw on battery when operating it..with motor running ..even while under way ..i see my voltage drop dramaticly..when on muffs and push up and down ...loss of rpms and voltag gos from 14 down to 10 0r9..let off buttun everything back to 14 volts..no draws when bilges,,,wash down pump,,lights or any other accssories..wouid this cause my motor to go into a low power mode if the battert gets drain down to much while oprating it while undrway for a few miles...fine when first start out..after about half hour motoring ...will cut down to 3000rpms and stays that way rest of day..can shut off restart but wont get over 3000..usually top out at 5300rpm..any responses back appreciated..Joe
 
A voltage drop on a voltmeter could be due simply to a failing battery, loose cable or tight but dirty cable at some point, a PTT electric motor shorting out, etc etc... the list goes on... BUT... none of this should have any effect on the engine's performance.

However... your statement of the engine losing 2300 rpm, dropping from 5500 to 3000 rpm and staying there for the rest of the day is what should be looked at first. I assume this condition, from how it's worded, that it is a every day happening or close to it. Things to do first....................

Compression: With "all" spark plugs removed, take a compression check and make a note of "all" of the individual cylinders psi readings for our viewing.

Spark: Still with the spark plugs removed, using a spark tester whereas A air gap of 7/16" can be set, the spark should be a strong blue lightning like flame... a real SNAP! Is it?

Please do not reply with generalities such as the compression is great and the spark good as that means nothing, be precise.

I'll now be turning this thread over to other members now as I retired in 1991 and some of your engine's design may be foreign to me... however, the tests I listed above are definitely your engine's needed starting point.
 
Disconnect the black/yellow shift cutout wire from the shift interrupter switch <--- Disregard this mention. It doesn't pertain to the V4 model as per racerone's jogging my memory.

I re-read your post closely where you state "loss of rpms and voltag gos from 14 down to 10 0r9" and take that to mean that every time you hit the PTT switch, the rpms drop to 3000. If this is the case, the PTT electrical circuit is wired incorrectly and is throwing voltage to the ignition system somehow.
 
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i guess i should reword thread...obviously 2 seperate conditions going on...main problem is loss of rpms..after running for a while it will cut down to 3000rpms.for rest of day...next day ..will run 5300 for a while cut done to 3000..for rest of day..starts up fine...idles fine..no stalling...as i mentioned with voltage issue i noticed voltage drop on gage when trimming up or down..was wondering if after trimming it would draw battery down enough to put motor in that mode...or maybe stator going bad...sorry about confusion..Joe
 
Hook up a timing light to # 1 cylinder.-----Start motor.-----Observe the flashing light.-----If it flashes you have spark.--------Go out on the lake.------When motor falters hook up the timing light to each cylinder and observe the light.------No flashing means that you have no spark !!
 
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