OUTBOARD TROUBLESHOOTING GUIDE
HERE'S HOW TO ANALYZE AND ISOLATE THAT PESKY
|Basic Rules For Troubleshooting!
|1. Proceed logically!
|2. Believe Your Evidence!
|3. NEVER ASSUME ANYTHING!!
|4. Check Everything. You
could have multiple problems!
Proceed As Follows;
Your motor needs THREE things to function
In spite of rule (3) above,
I ASSUME you are in possession of basic mechanical
skills, have adequate tools, have read my DISCLAIMER and the FAQ page. You have eliminated BOAT and SETUP
problems from mechanical ones. If you are unsure, either contact
me directly or SEE A CERTIFIED TECH..
Thanks! Now, lets get down to business.
A: Compression. Often
overlooked, most important! In A 2 cycle, must exist at proper levels
in both cyls & crankcase for peak performance. Should not vary over
15 lbs between cylinders. Any more than that, & you need powerhead
work. Sorry! If that's O.K., check "leakdown" or the tendency for
the flywheel to "bounce" off compression when flipped by hand. It
should resist & tend to recoil back. If it just sorta oozes by,
it's probably overhaul time. Occasionally, crankcase compression
may be at fault. A running motor that backfires, spits fuel back
thru carb, runs "rich" & idles rough may have this problem. Don't
B: Ignition. This
area is the most troublesome of all systems, and the engineers have
had a field day with it. The only consistency is, they all have
trouble spots. If you have a late model OMC O/B with "OIS" (Optical
ignition System) bite the bullet & get tech help from a dealer with
COMPETENT techs (Ask for credentials) and correct tools. Older "CD"
systems require only systematic following of the electrical path
from key to spark plug . Same for older magneto and battery ignitions.
Just imagine it's a water pipe, look for leaks, breaks, and blocks!
TIPS. On most CD systems, 250+ volts travel to the key switch, thru
a black wire with a yellow stripe. Disconnect this wire at the "pack"
to eliminate the entire harness & switch from the system. If that
does it, choke O/B to stop & take corrective action. If you have
spark on some cyls and not others, try reversing leads & use logic
to isolate bad coils, sensors, packs, etc.. READ your spark plugs!
They will tell you more about the condition of your engine than
ANY other test! I'm an excellent ignition diagnostician, contact
me now for help with your tough electrical
C: Fuel. This
area is LEAST likely to be at fault, and the most abused system.
Drain all of your lines, pumps, and carbs every season, and you
will probably never have fuel problems, If you are the victim of
varnished system and "sour" gas overhaul the ENTIRE system. REPLACE
ALL the fuel lines. Rebuild the FUEL PUMP(S). Otherwise, you'll
never get it to run reliably again. As for troubleshooting, remember
the plumber & look for leaks, breaks & blocks!
IF you wish to service or repair your own
outboard, I HIGHLY RECOMMEND you obtain an OEM model-specific service
manual to help you. We have most available RIGHT
HERE at Mastertech.
Hope I have helped you along the way -- tell
a friend about MASTERTECH. Thanks, BILL