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ContinuousWave: Whaler Repairs/Mods
engine brain surgery
|Author||Topic: engine brain surgery|
posted 02-15-2002 10:34 AM ET (US)
I have had problems with my 1987 150 evinrude. I've debated buying a new engine, a new boat, etc... I know now that I definately do NOT want to spend over $8k for a new engine for my 18' I DO want to get a larger NEWER boat especially the engine(s). I however need to save up and take my time looking for the right boat "whaler ofcourse". So this leaves me one option as I see it, to rebuild the tired 15 yr old evinrude. The compression is good and the lower unit is sound so I just have cosmetics, "some" rust, and the big issue electrical provblems.
The motor misses intermittenly of which the frequency is becoming more often. I have pretty much ruled out fuel problems and am 99% positive that it is spark (mechanics opinion too). The alternator doesn't supply the correct amount of juice either.
What I plan to do now is to replace all electronics my self. I was wondering if anyone has done this before? If so where should I start under the fly wheel or at the cylanders? Any comments would help this will be my very next project. Thanks in advance
posted 02-15-2002 12:04 PM ET (US)
First thing I would do is run the motor in the dark and mist all coil and spark plug wires with water.If there are any wires leaking to ground they will show up as an electrical arc to the block.The miss may simply be a faulty spark plug or coil wire.
posted 02-15-2002 12:05 PM ET (US)
As I learned firsthand last summer, you will need an impact wrench to remove the flywheel nut. Then a tool to pull the flywheel off the shaft. (An automotive "harmonic balancer puller" may work.) If you get past there, you can replace the stator, which may be the root of your problems (bad charging; bad spark).
I think the stator is an all-in-one part, and thus expensive (~$300). (On my Yamaha they have three separate coil assemblies, each about $80, so you can replace just the one you need.)
You will probably have to re-time the engine after replacing the stator. You'll need a timing light.
posted 02-15-2002 01:39 PM ET (US)
George- If it is just missing I would not do brain surgery. Had similar problem. Sounds like ignition coils- $22 a piece, I had 2 bad ones. The deteriorating missing sounds like what happened to me. If you need a new rectifier they go for about $200 plus a power pac goes for about $200. Test the coils first, may just be something simple. David
posted 02-15-2002 01:52 PM ET (US)
I might be a little clearer in saying it is more than a simple miss. The engine bogs out and doesn't seem to run on full power or if you prefer all cylanders. I just ran the boat and it ran great. Very intermitten! But it is becoming reliably unreliable.
posted 02-15-2002 03:38 PM ET (US)
Don't use an impact to remove the flywheel nut. You will potentially dammage the roller bearings in the crank & wrist pin bearing areas by the slamming action of the air wrench. Make up an adaptor to lock the flyweel using its tapped holes as a pruchase. You will need a puller, I made one however you might get by with a steering wheel puller by someone such as KD or Leslie. Use the puller & do not hit the end of the crank with a hammer!!!!!
The coil located under the flywheel is one pc including the charging windings for the alternator and the coil pack windings for the ignition. Replacement is pretty much a plug & play operation. When reinstalling the plug connections coat the seal faces with isopropal alcohol. The seal surfaces are the male/female (ID-OD) surfaces on the black plugs. Assemble while wet. The alcohol used should be medical grade (for wiping before an injection) without any oils etc. When assembled the alcohol evaporates and the elastomer surfaces contact and create a moisture proof mechanical seal. You also might want to check the magnets in the flywheel. Also check wires in the plugs where they enter the molded plug connectors by using a VOM & moving them (the wires)to check for intermittents. Check the coils on your existing installation with an Ohm meter for open segments. I would agree with DR that the coil packs is where I would be looking first for the miss.
The bogging down sounds more on the line of fule starvation due to collapsed fuel lines weak pump or even restricted tank vent. Check this out carefully as fuel starvation can make the engine run lean & then burn up! One quick check is to pump the fuel bulb when the condition is encounteded to check fuel flow.
posted 02-15-2002 05:06 PM ET (US)
George- I still believe multiple coil failure is the problem. David
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