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AQ145A dwell dropping off/running rough

E

ericfragola

New member
Hello boating community !

I have an 82 Gibson with an AQ145A motor. We've been chasing an issue that keeps us from running. Now that we're running, can't fine tune the motor.

Bottom line - the dwell is dropping off when the motor is under load/revving the rpms. It has new points which are set properly @ 62 degrees during idle. When you Rev the motor, it drops down to about 40 degrees.

History :
Cruising along no problem. Felt a sputter....kept going, then it cut out. Not able to restart. Coil had gone bad...replaced the coil, some wire connections etc. Now we have fixed the spark issue but it's still running rough. Replaced the spark plugs and wires, cap, rotor, points and condenser, set the dwell. Went to set the timing but While revving the motor, the dwell drops off. From the set point of 62 degrees down to 40.

From what I've read, that can be either of 2 things.
1- bad springs on the points (but it has new points)
2- bad distributor shaft bearing and it's wobbling under load

For 1 - considering the electing igniter upgrade to rule out the points and also never have to deal with setting them again.
For 2 - can't seem to find a new distributor or rebuild kit

For the symptoms of dwell drop off, could it be either of the above two?
- any leads on where to get a new distributor that isn't 1,000USD?
I pulled the Bosch distributor number - 0 231 178 017 which now transfers over to 855712 but they are either over 1,000 USD or unavailable.

Any suggestions or ideas on what could be the problem? Things to look at, try, or replace?

I believe the next steps to try are
1 - clean the lobes on the distributor and grease them
2 - get a new distributor. But with the unavailability of that distributor it's hard to find.

Thank you!

Eric
 
From what I've read, that can be either of 2 things.
1- bad springs on the points (but it has new points)
2- bad distributor shaft bearing and it's wobbling under load
Click to expand...

That would be my vote.


Dwell angle (in degrees) represents the duratioin at which the ignition coil is being saturated (per one cylinder's worth of dedicated distributor degrees)
4 cylinder dwell math:
360 distributor degrees divided by 4 cylinders = 90 degrees.
Dwell angle may be anywhere from 48 to 54 degrees of the 90 degrees. (depending on the engine)


In other words, dwell angle represents the amount of distributor degrees dedicated to "points closed" ........ or as with an electronic triggering device, the coil saturation is "active".

A worn distributor shaft will cause "wobble" that will most definitely affect the dwell angle.



When you get this resolved, be sure to not only set/adjust BASE advance, but to also look closely at what the "progressive" and "TA" are doing. (see your OEM specs for this)
.
 
If you have the condenser on the outside of the dist., make sure it is tight. On my boat, the screw bottomed out leaving the condenser loose making intermittent loss of spark.
 
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