Posted by Charlie Garrett on May 23, 2005 at 22:09:21:
In Reply to: motor help???? posted by Breamman on May 22, 2005 at 18:12:17:
I am not an expert on this model. Most of the suggestions I have read are probably 90% correct. It definately sounds like a clogged idle jet. However, I have learned after 20+ years of "shade tree" work, that some other things need to be considered.
The first thing I always do is run a compression check. Find a buddy with a reliable gauge or buy one. A 1996 model is not considered old (by me), but you can waste time and money not knowing if the powerhead is OK. This helps rule out rings, head gaskets, Plug seats, etc. If the problem lies in those, rebuilding the carbs obviously won't help.
The next thing to check is the timing. This is usually only needed if you have not owned the motor very long or have had chronic problems. Most outboard timing is factory set and does not need adjusting (unlike older model vehicles where everybody tried to squeeze more HP by advancing the timing), but you need to be able to "Rule it out". Also check to make sure you have the CORRECT plugs and they are working. Pull them, connect the wires and ground them and observe the spark while cranking. This is a poor man's check, they could still act up after getting hot.
If Timing and Compression are OK (you need specs on each), You need to decide if it is lean or rich. In other words, is it starving for fuel, of flooding. Usually, if you can choke the motor as it is dying and it keeps running, it is starving for fuel. Choking or enrichening usually means a clogged idle jet (the most common problem as most people have commented here).
If it does not help to choke it, it can still be clogged passages in the carb or a float stuck. A motor with a float stuck OPEN will usually not run long and will exhaust unburnt fuel (smells like gas rather than exhaust). Choking usually makes it worse, it immediately dies. A 2 cylinder (50HP) motor with a float stuck CLOSED will barley run, if at all, because only 1 cylinder is working.
FYI - The OMC carb cleaner it excellent. Take apart the carbs, soak them in it and let then sit overnight, then clean with compressed air. Stay away from the Acetone based carb cleaners unless you completely remove old gaskets and seals, they can melt and make things worse.
my 2 cents
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