79 DT5 Points-Timing Mess

[Devildog 1994]

Hi All, Great Site Here!

I have a DT5 from 79, having trouble dialing in the points and timing.

The #2 cylinder will run the motor but not #1. However, i can hear a difference when I pull the #1 plug so I know that #1 is doing something just not enough to keep the motor going around.

Both sets of ignition have very good spark and the thing is getting plenty of gas so I am convinced that it's a timing issue here.

I know that it is something that I am not doing right because just a few days ago, the #1 cylinder was running fine on its own and #2 would not sustain the motor unless it was higher RPMs, would not idle on just #2.

So, in addition to timing the points correctly, there is a stator plate that advances via cable as you dig into the throttle. Which is fine but the cable has about .75 inches of adjustment so I don't know where that should be or how I find the happy place for that cable adjustment.

Does anyone have a service manual that they can send me a pic of the points page or transcribe the finer points of points adjustment? (Pardon the pun)

I've included a pic of the flywheel. On the pic, you can see the marks on the flywheel and also the T mark on the engine case. When She's running the mark that's above the T2, which represents absolute TDC, is about where you see it now when I use a timing light. If I give it more throttle and the timing plate advances, the mark moves earlier. Does anyone know where the TDC mark should be when Idling relative to the T on the case? I thought it might be closer the the engine case T mark but I'm not sure. Does anyone know what the marks on the bottom of the T2 represent? Degrees BTDC perhaps?

I am thinking that if the engine is running optimally, it should be able to run on either single cylinder.

Thanks for any help and please let me know if I can clarify anything.

[artdf175]

You will have to see if someone with a manual chimes in here
But at idle it should be at some degree BTDC
My '06 df175 the ECU keeps it within a range of 5 degrees +\- 5degrees BTDC

When running it runs within a range of BTDC 5 degrees to 26 BTDC
I would try 5 degrees to start with maybe as high as 10

Good luck

[Devildog 1994]

Thanks, at Idle, it looks like a decent 15-20 degrees if in fact the line above T2 is the measuring device.

TDC does last itself for a few degrees so I guess it would be hard to identify absolute TDC.

[artdf175]

I think the flywheel itself has the degrees marked on it
So with the engine running the timing light should light up the marking with the arrow or maybe the T on the cover

[Solarman]

As a general rule, if a motor has one cylinder, then there is only one TDC. If the motor has multiple cylinders, then to balance the running of the motor, TDC for each of the cylinders is equally distant from each other in the rotation of the crankshaft ( 2 cylinders, 360° ÷ 2cyl = 180° apart). A two-stroke, 2 cylinder motor would fire each revolution of the crank, a four-stroke, 2 cylinder requires 2 revolutions for each cylinder to fire.

The best method to time a motor with points and stator plate (under the flywheel), is by static timing. Usually because the flywheel needs to be off (generally) to set the points, after setting the gap to specs, you can static time the motor with the flywheel removed.
You should have the manual to set the timing and carb(s) for your motor properly. There is a website that sells older outboard motor manuals (reasonably priced), but you might have to Google it. I can't remember the name.

Good luck. Post back how it's going when able.

[Devildog 1994]

Thanks for the info.

Well, I have them both up and running but now neither will idle alone. One cylinder will sustain the motor only in the higher rpms. I have seen each idle the motor by themselves previously but not now.

Here is a shot of the #1 cylinder at idle with a timing light.

[Devildog 1994]

Here is a shot of the #1 cylinder, obviously the previous one was #2 and not 1.

This shot also while idling with a timing light.

[Devildog 1994]

One other question would be... For a 5 horse two cylinder engine, should the engine idle fine with only one cylinder pulling? Like if you pull the plug wire off?

Thanks for any help on this and my previous questions!

Mike