Need advice ... No spark??

[x-bird]

So i got the 750 put back together and ready to fire up. Fuel pump works, starter works ---i'm happy ... juice it and i get zip. no spark, all else seems good. cranking, fuel, but no fire. the wiring diagram is below. I followed it since i didn't have a harness. basically everything that is routed to "d" and "e" on the ign switch is twisted together and attached at the starter pos. post (using jumper cables off my truck battery) "C" is kept solo to crank it, my grounds i've hooked to an exhaust stud where i clamp the battery negative. None of the gauge leads have been connected. Just the regulator, fuel solenoid at the carb, ignition and starter.

It seems like an issue in the flywheel/coils/stator somewhere.
Is the air gap between the ignition coils and the flywheel magnet super critical? I tried to set it evenly with less than a 1/16th.
The black leads off the coils i have hooked together, but floating with no contact with pos. or neg. If I'm correct, they're basically a kill switch which would shut it down if i grounded them (B to A on the ign switch).

What are the best ways to troubleshoot the components (coils, regulator, stator ) to see what's the cause? I can't be dumping money into this thing, so i don't want to just throw parts at it til it runs. :banghead:
Thanks

[metalstudman1]

The air gap is usually about an 1/8 and not critical unless the flywheel magnets are gone- simple test, flathead screw driver a 1/4" away should be attracted to the magenets. Can you post pic's of the flywheel,stator and coils and any wires coming from the stator?I can't really read the schematic!!! Is the regulator the item that's in the center?To be able to check the stator coils you'll have to have the ohm values from the factory.Simple test would be to hook up a test light to the coil plug coming from the stator to see if the issue is the coil, test light lead to ground and touch light tip to coil connection to see if it's getting anything when the motor is turning over.

[x-bird]

I'll put up some pics this am. Drained and took the radiator off last night so i could do just that. I'll reshoot the schematic as well (my scanner doesn't work)

That is the regulator in the center. The stator wires feed into it--they had to be cut when i replaced the engine--the plug was corrosion fused together. In the regulator plug, the ground and positive feeds are on the terminals on the other side of those. I'm also wondering if the female terminal ends i put on the wires are too close inside the plug end. The original regulator plug end had plastic divider walls in it.

The stator wires should give me 12v+ when cranking, correct?

The way I read the schematic, it appears that the stator is just supplying voltage back to the battery for charging and the ignition coils should be supplying spark voltage independently. Single magnet on the outside of the flywheel seems plenty strong, as do the ones inside. I did have to reattach one of the inside magnets--they seem strong enough as well given how many tools they kept gathering when on the bench.

Any chance that the coils are specific to cyls 1 and 2?

Does the regulator factor into the ignition voltage?

As far as getting any type of values for this engine, I've really been striking out on that. Even though it's still on the market manuals and specs seem to be closely guarded secrets lol--cant get a service manual for it.

Years ago we went through a period with this engine where no one could get it running, two different scag shops went over it. The regulator was replaced along with the carb solenoid, fuel filter, fuel pump and some wiring connections. After they were done with it, (and paid lol) I finally found that the fuel line was plugged between the tank and filter. I still have the original regulator and fuel pump as spares. I also have a pair of stators from our 15hp Kohlers, slightly different coil array, (i think they're 10-post and this one is 12 iirc) no idea if they'll fit dimensionally.

[x-bird]

Think I got it licked .... the coils are specific to position.

Hooked the multimeter to one and got negative voltage. because they're assembled with the plug wire coming out one side and both are identical as to that lay out, swapping them reverses the direction that the magnet passes the pickup. Reversed one and i've got spark. I'll button it all up again and give it another whirl--and hopefully make a lot of noise )))))).

Stator (charging coil) is putting out 1.6-2.0 volts, which should be correct for a feedback voltage to keep the battery charged, right?

[metalstudman1]

Engine runs CCW so yes the coils are in-line with that rotation and specific.I'd say you resolved your own issue!!!The stator putting out that much with just the starter turning it over is really good!!! Just to answer the question about the regulator/rectifier- No it doesn't have anything to do with ign/spark, as in the schematic there's only 2 wires leaving the windings/coils for charging and powering the fuel pump,carb soleniod and lights.Hope you get it fired up-

[x-bird]

Yep, was just the coils mounted wrong, one of them had a #2 on the back, the other was unmarked. the vent cover above the flywheel has a 1 and 2 on it, identifying the cylinder banks. Too simple! Sometimes I can't figure this stuff out until i put it in words and stare at them long enough for it to sink in. Fired up with no issues, warmed it up on idle, gave i about 5 minutes of part throttle then ran it all the way up. I have a 2-min full throttle video uploading to utube that i'll post. Soooooo, who needs a 27 hp Kawasaki????? ))) I'm thinking in the 500-750 price range--that sound reasonable for something like this?

[x-bird]

Mike, it's calling youuuuuuu .... )))
http://www.youtube.com/watch?v=1Woz04yLJZ8

[metalstudman1]

I'm not interested (no money!!) but would like to know how heavy that engine is and size of the shaft.

[x-bird]

128 pounds without fluids--that's with the starter radiator etc. 1 1/8th shaft with 1/4 keyway.

[metalstudman1]

Thanx!

[x-bird]

fwiw shaft comes out 3 and 3/4. The mower it comes in is the 72-in. cut commercial Scag, pretty much their top dog. uses a pretty beefy--and expensive -- electric clutch for the deck drive while the hydros run off a keyed pulley.

[speedshopmike]

Mike, it's calling youuuuuuu .... )))
http://www.youtube.com/watch?v=1Woz04yLJZ8

ok, but only if those shoes come with the deal.
btw, i was out with the sandrail chassis today.
it does indeed have rear control arms, hubs & freely spinning stubs, and a vw engine cradle; one side has the drum brake there, other doesnt but it might be in parts box.

[x-bird]

ohhhh crap, i gotta delete that vid, you're not the first one to pick on my rics :biglaugh: They're a nice shade of ground-metal grimy red now ... dropped a hot weld slagger through them last night! :doh: :crying: Sold the beast last week. :crying: It kept giving me really expensive ideas about what to do with the ton+ of 2x2 bent up square tubing i have kicking around. :D

Back to reality, i really think you've got a 2 to 3k piece sitting there, spring/early summer may be the best time to move it.

[buggypowermaker]

this is this one kind of spray you can put in the spark plug cap. ill have to get the name for ya.