Logo
FULL SITE MENU

1987 evinrude 140 E140tlcua

E

eathen13@

New member
1987 140hp
1994 javelin 363b 17ft bass boat
6” jackplate set at about 3.5” ptp
19p prop new prop an hub
Compression 120/120/120/118

So I’m having a weird issue going on with my outboard and at this point I’m stumped , it’s starts and idles great , go to take off and plain out it hits a 2900-3000 rpm wall and a couple of times it has stuttered and come alive boat planed out and ran great , stopped and fished and it hits that 3000 rpm wall , squeezed primer bulb and no change , pushed in key to choke it an no change , tried 3 different prop sizes and all do same thing , started testing ignition and got DVA weird reading on one pin of timer base so ordered a new one and a stator while I’m at , replaced and set timing at 18 degrees per manual , still no change and verified link an sync timer is freely turning , I’ve ran boat on portable tank with new line and primer bulb and verified proper vent and no change , list below of what’s been replaced or tests done etc.


All fuel times tank to carbs an pulse line
Fuel pump
Carbs rebuilt
Power pack -Sierra
Stator-oem
Timer base-cdi
Plugs -ql77jc4
Water pump
Thermostats and diaphrams
Grounds cleaned
Ran with timing light each cylinder no difference
Portable tank new lines an bulb no change
Raised jackplate an no changed
Ran 15p prop 19 p prop an same
Disconnected kill switch an no change
Main jets are 59d


What am I missing why won’t it run past 3000 rpm?
 
Does spark jump a gap of 3/8" on each lead?---Orange / blue stripe wires on top coils?------Flywheel key checked?-----Flywheel magnets checked?------Reed valves checked?-----Looked into issues with crankshaft sealing rings?
 
racerone said:
Does spark jump a gap of 3/8" on each lead?---Orange / blue stripe wires on top coils?------Flywheel key checked?-----Flywheel magnets checked?------Reed valves checked?-----Looked into issues with crankshaft sealing rings?
Click to expand...
I have not checked spark in awhile I’m gonna check tonight , , yes blue to the sky , flywheel key is good , I’ve checked flyweel and no magnets looked out of order I’ll remove it put a picture for verification , I have not maybe it’s time I do a leak down test , I’ve sprayed starting fluid all over and didn’t notice any rpm difference
 
racerone said:
Does spark jump a gap of 3/8" on each lead?---Orange / blue stripe wires on top coils?------Flywheel key checked?-----Flywheel magnets checked?------Reed valves checked?-----Looked into issues with crankshaft sealing rings?
Click to expand...
Just did spark test and found one cylinder firing irratically , replaced coil with a Chinese one I had laying around and spark is now consistent , gonna order a set of new oem or cdi coils and go from there
 
eathen13@ said:
Just did spark test and found one cylinder firing irratically , replaced coil with a Chinese one I had laying around and spark is now consistent , gonna order a set of new oem or cdi coils and go from there
Click to expand...
Replace the ultra-cheap one for sure, but save your $$ for other parts. Another tip is to remove the engine cover and run it in the dark under load while watching all the coils. The plastic on old coils can crack and when under load you can see stray arcs to the block which will rob you of voltage reaching the spark plug. A good way to do this test is to keep the boat strapped to the trailer and back into a ramp so you can put in gear and give it throttle without worries of bouncing down the lake.

If you see no stray arcing then it's likely your 3 older coils are fine and there's no reason to replace them.
 
I don't see where your original power pack would have an RPM limiter for overtemp conditions BUT perhaps the later supersessions did? IDK. Maybe I missed it in the service manual?

Since that engine was VRO, the overtemp, low oil quantity & no oil signals would have all gone thru the power pack to send the various signals (as in steady, 40 second beep & 1/2 second beeps) to the alarm. (There is only 1 signal wire plus a ground at the alarm, the power pack sends out the various signals to the alarm).

Are you sure the alarm functions? Does it beep once when key is turned to "on"? Does it sound a steady horn if you short an overtemp sensor to ground?

Because it essentially RPM limits at 3000 it sounds electrical.
Fuel delivery, incorrect prop, engine height can all affect performance but not that consistently.

You have replaced the t-stats & water pump so it's probably not overheating & certainly not immediatley after engine start but a faulty temp sensor or tan wire shorted to ground could give a false signal. So IF the power pack has an RPM limiter function for an overtemp condition whether real or false signal.....

You should have an RPM limiter function for exceeding the red line. I think about mid 6000 range. That is in the service manual, I just don't remember the exact RPM it limits to.

The tach signal is generated by the rectifier but IDK if it can affect the RPM limiter function.
 
From what I can find in the service manual it DOES NOT but if there were any supersessions in the power packs maybe one it does now?
 
Droid said:
I don't see where your original power pack would have an RPM limiter for overtemp conditions BUT perhaps the later supersessions did? IDK. Maybe I missed it in the service manual?

Since that engine was VRO, the overtemp, low oil quantity & no oil signals would have all gone thru the power pack to send the various signals (as in steady, 40 second beep & 1/2 second beeps) to the alarm. (There is only 1 signal wire plus a ground at the alarm, the power pack sends out the various signals to the alarm).

Are you sure the alarm functions? Does it beep once when key is turned to "on"? Does it sound a steady horn if you short an overtemp sensor to ground?

Because it essentially RPM limits at 3000 it sounds electrical.
Fuel delivery, incorrect prop, engine height can all affect performance but not that consistently.

You have replaced the t-stats & water pump so it's probably not overheating & certainly not immediatley after engine start but a faulty temp sensor or tan wire shorted to ground could give a false signal. So IF the power pack has an RPM limiter function for an overtemp condition whether real or false signal.....

You should have an RPM limiter function for exceeding the red line. I think about mid 6000 range. That is in the service manual, I just don't remember the exact RPM it limits to.

The tach signal is generated by the rectifier but IDK if it can affect the RPM limiter function.
Click to expand...
I checked the alarm the other day cause it never did anything with before , put new spade connecters on an cleaned ends and turn key and it has a continuous alarm sounding , I’ve disconnected temp sensors previously and didn’t change anything , I’m at a loss here lol
 
eathen13@ said:
I checked the alarm the other day cause it never did anything with before , put new spade connecters on an cleaned ends and turn key and it has a continuous alarm sounding , I’ve disconnected temp sensors previously and didn’t change anything , I’m at a loss here lol
Click to expand...
Previous owner disconnected vro I have not looked into that
 
Back
Top