I'm more familiar with 4 stroke engines (motorcycles & cars) than I am 2 stroke marine. I haven't had a chance to get into this engine to confirm visible problems like fuel supply blockages as of yet.
I know that getting a service manual is likely step one in troubleshooting & maintaining this outboard, but I figured I'd ask here for the time being:
I recently picked up a well used but apparently well maintained mid 80's Johnson 15. According to the PO, it got new plugs, new impeller, carb tune (or rebuild) and lower unit oil change done before I bought it. Plugs, wires look good (haven't confirmed correct plug numbers I have to admit); outside of carb is very clean, indicating that it's probably been removed and worked on. Done correctly? I don't know.
I've hooked it up to a new plastic tank/connector/fuel line with full tank of fresh gas & proper mix* w/quality o.b. premix, primed the bulb to firm, confirmed airtight connections up to the engine....and it will start on the first or second pull.
After warming for a bit, choke goes in and it will idle fine. All day if I kept it at idle.
However upon brisk acceleration, it will die as though it's being robbed of fuel. It doesn't miss or run rough, it just dies off. It will die off even upon gradual acceleration. Although I've been able to get it up to higher rpms a few times, it's nearly impossible to do w/out dying.
Sure seems like a fuel issue to me; as if there's a fuel filter somewhere that's limiting the flow, or a clogged main jet(?) I've tried to pump the bulb while it's starting to die, and that does no good. Line connections up to the engine seem airtight.
If I quickly back the throttle off to idle, it will return to idle w/out cutting off; however if I try to gradually throttle down after trying to accelerate, it will die altogether.
I've monkeyed with the mixture dial to no avail.
I'm looking for some guidance as to where to start.
I am watching the thread "1979 15 Evinrude loss of power, rough idle" and will likely follow the suggestions to troubleshoot, as the symptoms seem very similar.
A few additional questions that I should know:
I was told that after seating the mixture dial, turn out 1 1/2 turns and fine adjust from there. Am I adjusting idle, or high speed with this?
*Also, this has a factory decal indicating a 100:1 fuel/oil mix. This seems like not enough oil in the mix for any 2 stroke - regardless of the quality of the oil. Has this ratio been updated or should I stick to this?
Thanks in advance,
J.P.
I know that getting a service manual is likely step one in troubleshooting & maintaining this outboard, but I figured I'd ask here for the time being:
I recently picked up a well used but apparently well maintained mid 80's Johnson 15. According to the PO, it got new plugs, new impeller, carb tune (or rebuild) and lower unit oil change done before I bought it. Plugs, wires look good (haven't confirmed correct plug numbers I have to admit); outside of carb is very clean, indicating that it's probably been removed and worked on. Done correctly? I don't know.
I've hooked it up to a new plastic tank/connector/fuel line with full tank of fresh gas & proper mix* w/quality o.b. premix, primed the bulb to firm, confirmed airtight connections up to the engine....and it will start on the first or second pull.
After warming for a bit, choke goes in and it will idle fine. All day if I kept it at idle.
However upon brisk acceleration, it will die as though it's being robbed of fuel. It doesn't miss or run rough, it just dies off. It will die off even upon gradual acceleration. Although I've been able to get it up to higher rpms a few times, it's nearly impossible to do w/out dying.
Sure seems like a fuel issue to me; as if there's a fuel filter somewhere that's limiting the flow, or a clogged main jet(?) I've tried to pump the bulb while it's starting to die, and that does no good. Line connections up to the engine seem airtight.
If I quickly back the throttle off to idle, it will return to idle w/out cutting off; however if I try to gradually throttle down after trying to accelerate, it will die altogether.
I've monkeyed with the mixture dial to no avail.
I'm looking for some guidance as to where to start.
I am watching the thread "1979 15 Evinrude loss of power, rough idle" and will likely follow the suggestions to troubleshoot, as the symptoms seem very similar.
A few additional questions that I should know:
I was told that after seating the mixture dial, turn out 1 1/2 turns and fine adjust from there. Am I adjusting idle, or high speed with this?
*Also, this has a factory decal indicating a 100:1 fuel/oil mix. This seems like not enough oil in the mix for any 2 stroke - regardless of the quality of the oil. Has this ratio been updated or should I stick to this?
Thanks in advance,
J.P.