OUTBOARD TROUBLESHOOTING GUIDE

HERE'S HOW TO ANALYZE AND ISOLATE THAT PESKY PROBLEM

• Compression
• Ignition
• Fuel

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 overlook it.

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 troubleshoots.

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