tlocus73
Seaman
- Joined
- Aug 18, 2008
- Messages
- 51
Hello,
Been reading several posts here on tuning an outboard. Also looking at my manuals but had a few things I wanted to make sure I'm on the right path.
Engine: 1989 Johnson GT100 J100STLCEM (V4)
-Did a compression check a couple of weeks ago and got all good numbers.
-New spark plugs Champion QL77JC4
-A few weeks back I replaced my throttle cable. Got it pretty close but now it idles just a bit low and just a bit rough
(rough I mean, idling in forward and ocasionally going between 500 and 600 RPM). I have to add that when I give it just a bit more forward throttle..maybe 700 RPM, engine runs smooth.
-I didn't change or adjust anything on the engine yet (Timing, idle screw, etc...)
-The idle stop screw is probably about 3/16" away from the stop. If I try and adjust the dial on the cable to where it's touching the stop, the RPMs drop and engine will cut off.
I'm guessing the old throttle cable was either stretched or worn out(it broke and got new cable) and therefore getting the lower RPMs with the new throttle cable?
I remember reading on the forums here, someone mentioned to adjust the idle you should alter the timing?
I'm aware there are 2 timing numbers/procedures...Full throttle Spark advance degree(28?) and Throttle pickup degree (4-6?).
Guessing I would need to adjust the Throttle pickup timing to adjust the idle?
Also, for the Full throttle Spark advance, which requires 5000 RPM(?), this must be done in a tank with test wheel installed?
Here are in order some tune up procedures (in order) I've gathered from a post I've read here:
1)Adjust timing pickup
2)Adjust idle by reducing timing advance
3)Unhook throttle cable from engine and use a rubberband to keep the throttle arm against the stop while adjusting (the above?)
4)When above is adjusted, re-install & re-adjust the throttle cable.
Is this correct?
t
Been reading several posts here on tuning an outboard. Also looking at my manuals but had a few things I wanted to make sure I'm on the right path.
Engine: 1989 Johnson GT100 J100STLCEM (V4)
-Did a compression check a couple of weeks ago and got all good numbers.
-New spark plugs Champion QL77JC4
-A few weeks back I replaced my throttle cable. Got it pretty close but now it idles just a bit low and just a bit rough
(rough I mean, idling in forward and ocasionally going between 500 and 600 RPM). I have to add that when I give it just a bit more forward throttle..maybe 700 RPM, engine runs smooth.
-I didn't change or adjust anything on the engine yet (Timing, idle screw, etc...)
-The idle stop screw is probably about 3/16" away from the stop. If I try and adjust the dial on the cable to where it's touching the stop, the RPMs drop and engine will cut off.
I'm guessing the old throttle cable was either stretched or worn out(it broke and got new cable) and therefore getting the lower RPMs with the new throttle cable?
I remember reading on the forums here, someone mentioned to adjust the idle you should alter the timing?
I'm aware there are 2 timing numbers/procedures...Full throttle Spark advance degree(28?) and Throttle pickup degree (4-6?).
Guessing I would need to adjust the Throttle pickup timing to adjust the idle?
Also, for the Full throttle Spark advance, which requires 5000 RPM(?), this must be done in a tank with test wheel installed?
Here are in order some tune up procedures (in order) I've gathered from a post I've read here:
1)Adjust timing pickup
2)Adjust idle by reducing timing advance
3)Unhook throttle cable from engine and use a rubberband to keep the throttle arm against the stop while adjusting (the above?)
4)When above is adjusted, re-install & re-adjust the throttle cable.
Is this correct?
t
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