What Do the Plugs Say?

[racerone]

NO<NO-------The coils do not fire at the same time on this 2 stroke motor !!!-----Where do these wild ideas / guesses come from ???

 

[minuteman62-64]

NO<NO-------The coils do not fire at the same time on this 2 stroke motor !!!-----Where do these wild ideas / guesses come from ???

See circuit diagram: it's one coil, with one primary winding and one secondary winding. The secondary winding feeds the two plugs. How can they not fire at the same time?

 

[racerone]

The diagram is for what motor ?------2 stroke or 4 stroke ??----Taken from what manual ?

 

[Mohawkmtrs]

See circuit diagram: it's one coil, with one primary winding and one secondary winding. The secondary winding feeds the two plugs. How can they not fire at the same time?

Ummm...2 magnets (180* apart) on the flywheel?

 

[Sylva-Ranger]

I have the service manual (P\N 99500-94301-01E) for a '80's Suzuki DT-40 2 strokes ( The "T" in Suzuki models means "two strokes and DF means "four strokes" ) 2 cylinders whit the same type of ignition that some older 2 strokes Mariners like the 30 here, and they call that "simultaneous ignition system instead of the 'independent ignition system",

They say that the difference betwin the 2, is that the simultaneous system have only one coil and the independant have 2 coils.
at the page 113, paragraph one, they state :

"......this magneto is a tetra-pole type , and therefore the above operation is repeated twice per a compete turn of the magneto.In other words, spark takes place twice respectively in the upper and the lower sides at intervals of 180 degres"

If you whant, i can scan the pages of my manuals that explain that, ( including the page 113) and sand by e-mail or post here.

In the parts diagram for the Mariner 30A, whe see can only one coil whit 2 hi-tension wires, it's supposed to be a simultaneous ignition system like the Suzuki named above.

 

[flyingscott]

Take the plugs out and put spark checkers on and watch the spark. Make a video of of these sparking at the same time.

 

[racerone]

Are you say a plug would fire as the crankcase compression is scavenging the one cylinder with fresh air / fuel on a 2 stroke ?----Johnson / Evinrude built a 9.9 2 stroke and a 4 stroke in say 1996 model year.-----4 stroke fired both plugs at the same time.-----2 stroke did not have the same coil.

 

[jimmbo]

What is the Serial # of your motor?

Looking at the parts diagram for some 30A Mariners, it does show a coil with two plug wires. However, with out the Mariner Service manual for reference, I will not assume a Suzuki manual is showing the correct wiring diagram. Yes the Mariner part shows two wires in and two wires out, but there might be 2 coils within, sharing a common ground, via the mounting screw.

 

[minuteman62-64]

What is the Serial # of your motor?

Looking at the parts diagram for some 30A Mariners, it does show a coil with two plug wires. However, with out the Mariner Service manual for reference, I will not assume a Suzuki manual is showing the correct wiring diagram. Yes the Mariner part shows two wires in and two wires out, but there might be 2 coils within, sharing a common ground, via the mounting screw.

I have the actual service manual for my motor - the circuit diagram is from that manual. Unfortunately the manual does not have a blow-by-blow description of the ignition cycle as in the Suzuki manual. It is pretty clear that there is one primary and one secondary winding - with the secondary winding feeding both plugs.

 

[Sylva-Ranger]

I have the actual service manual for my motor - the circuit diagram is from that manual. Unfortunately the manual does not have a blow-by-blow description of the ignition cycle as in the Suzuki manual. It is pretty clear that there is one primary and one secondary winding - with the secondary winding feeding both plugs.

Make a vidéo that show you stop the running engine, Invert the 2 sparks plugs wires and try to start the engine again. Put it in YouTube and give us the link here to all of us can see the results.

We do that on 2 cyl 2 strokes snowmobiles engines for decades, if a wire is not long ennough for reach the spark-plug, usualy i use an "in line spark tester".

Maybee that don't work on this particular engine for any reason ? But when i read your winring diagram, i don't know why this ignition system is different That the Suzuki simultaneous ignition system above…..

 

[Sylva-Ranger]

Are you say a plug would fire as the crankcase compression is scavenging the one cylinder with fresh air / fuel on a 2 stroke ?----Johnson / Evinrude built a 9.9 2 stroke and a 4 stroke in say 1996 model year.-----4 stroke fired both plugs at the same time.-----2 stroke did not have the same coil.

Do you say it' impossible at all to see any 2 strokes 2 cyls outboard (or any other 2 strokes ) whit simultaneous ignition like Suzuki describe in their service manual ?

Or did you just say that the japanese 30A Minuteman's Mariner have not this configuration ?

I didn't see Jonhson, Evinrude or Mercury whit that configuration, but Some 2 cyl 2 strokes Suzuki or Japanese Mariner yes..............Did they have Something différents that just the ignition system to make that possible ? maybe ...

 

[flyingscott]

Now i"m confused ….Why the ignition can run on some 2 strokes outboard engine (usualy some Japanese engine like some Suzuki and older Mariner and Spririt) whit only one (double) coil and only one positive primary wire ?

And why can we reverse the sparp-plugs wires on a 2 cyl 2 strokes snowmobile (95% of them have only one coil whit one positive primary for the 2 cylinder) and the engine still running perfecly ? why this can happen if they don't fire at the same time ?

When have you ever reversed the spark plgs on a snowmobile and had it work? I have owned a lot of sleds and never managed to pull that off and make it work. I need some video for these claims.

 

[Sylva-Ranger]

When have you ever reversed the spark plgs on a snowmobile and had it work? I have owned a lot of sleds and never managed to pull that off and make it work. I need some video for these claims.

The first time ? probably 30 years ago, the last time ? about 15 mins ago especialy for you ! Look this link in YouTube :
https://www.youtube.com/watch?v=xqJd...ature=youtu.be

This is my 2007 Arctic-Cat Bearcat whit 2 cylinders, 2 strokes 570 cc carbureted engine whit reed-valves , you see the coil have only to primary wire. one positive and one negative (grund) , the coil is screwed ont the plastic case, witout any other wires ..

Like i said above, when one of the wire is to short when inverted, i use in line spark-tester to reach the spark-plug.

Sory for the quality of the vidéo, not easy to do it whit just one hand ...........if you whant i can make a better vidéo whit the help of a friend, and make a mark on each spark-plug cap so you can see they are realy inverted, whit running the snowmobile to be sure it's don't running backward …..I admit that When i wake up this morning, the first thing i thinked is't probably not that i have to start my snowmobile today september 17 to make a video ha ha ha !!

 

[minuteman62-64]

Make a vidéo that show you stop the running engine, Invert the 2 sparks plugs wires and try to start the engine again. Put it in YouTube and give us the link here to all of us can see the results.

We do that on 2 cyl 2 strokes snowmobiles engines for decades, if a wire is not long ennough for reach the spark-plug, usualy i use an "in line spark tester".

Maybee that don't work on this particular engine for any reason ? But when i read your winring diagram, i don't know why this ignition system is different That the Suzuki simultaneous ignition system above…..

Chances of me making a usable video - slim. Chances of me moving said video from my phone to computer, editing and then somehow getting it to YouTube - non-existent.

How's this? This p.m. I ran the motor with plug wires as they normally are. Shut it off, switched the wires and started it up again. Motor doesn't seem to give a rat's ass about the position of the plug wires. Ran the same at idle and about 1500 rpm in both set ups.

For me, question answered.

 

[flyingscott]

Wow I have learned something today. I will have to check my friends Spirit motor and see if it does the same thing.

 

[Sylva-Ranger]

Chances of me making a usable video - slim. Chances of me moving said video from my phone to computer, editing and then somehow getting it to YouTube - non-existent.

How's this? This p.m. I ran the motor with plug wires as they normally are. Shut it off, switched the wires and started it up again. Motor doesn't seem to give a rat's *** about the position of the plug wires. Ran the same at idle and about 1500 rpm in both set ups.

For me, question answered.

Tank you Minuteman to give us the results !