1987 WR250 SEM ignition problems.

Hi All,

First post, long time lurker.

I have a 1987-88 wr250, last of the swede's I think, bough cheap as a barn find, un ridden for 20 years, all original down to plastics and tyres. I have a problem however.

Bike was running OK, started really easy, 1st or second kick, every time, but had a miss or stumble on 1/2 to 3/4 throttle but would clear, it got better as it warmed up and never worried me enough to look for a solution as I loved riding it so much (still have a 85 WR240 also, not going though)

I had to store the bike for a few months when I moved house, bike was riden into the shed, fuel drained and ran out, all good, a few months later I get her out to ride, fuel up, KICK KICK KICK, no go.

Check fuel, choke, kill switch etc. no spark??? check all conections etc etc, no good.

It has a SEM ignition, all standard as far as I can see.

I did the resistance checks across the fields, also to ground checks, all within spec, flywheel was mounted right on keyway etc

Out of frustration and not being able to measure ANY voltage, even with scope, out of coil charge windings, I bought another sem stator, same model, NOS, I also got another coil, NOS, so I now have two stators, three coils.

Still no spark, I get a pulse from ignition/fire stator winding, but nothing from the coil charge windings, even with the spark plug out, and engine wound over with power tool, no output, tried both stators, all three coils, wiring is perfect, good earths etc.

The only thing I have not tried is the flywheel, I have one on my 240 which I can pull off, but do flywheels loose their mojo, I mean the bike was running fine, parked up for 4 months, now nothing.

I am tempted to buy an MZB ingniton set, but it is worth more than I paid for the bike.

I found some info on a Husaberg forum, as they also run the SEM set-up and have huge issues with quality control, one thread in particular showed how to use a CCFL invertor to power the coil, then use the ingnition pulse coil to fire the coil, I set this up and have a blue spark so big and load it will crack across a 20mm gap, but bike wont run.

I think the coils is firing off the coils charge magnets on flywheel not the trigger ones, as it will cough, then kick back, I tried to run start, same thing, timing is way off, but is all set factory settings.

Any leads on a replacment ignition that works, I dont need lights, as the bike is not rego'd, I have thought about trying to set up a Hall effect sensor to trigger the CCFl invertor powered coil, but there has to be a better way.

What aftermarket units are you guys running and are happy with, it is a "meduim shaft " crank,

The rest of the bike is so nice, still has factory swingarm decals, screen print on seat etc, all like new, but no spark.

Can I convert to a moplat? what flywheel would I need? this is driving me crazy. maybe the bike is rebeling against the 07-KTM525 EXC racing it now has to share a shed with, I f sell the Kato, will the sparks come back?

I just want to ride my old girl, I miss the vibes, the ping, the arm pump, please help.

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If I'm not mistaken SEM ignitions do have alot of issues including running backwards.

Don't even bother with the SEM ignition, swap over to a motoplat and you'll never have an issue again.

Or swap in an MZ-B ignition seen here: http://www.husqvarna-parts.com/catalog/item/3736881/4179072.htm Which I'd do personally if I had this issue as you're getting an updated and much higher output ignition which will equal more power plus it's BRAND NEW. It is pricey though so it depends on your budget. But when you look at the price of a brand new SEM stator being mid 300's this isn't too bad at all.

Hi, Thanks for the reply, I contacted that company yesterday to try and buy a MZB ignition from them, they no longer stock them, I have the order page for the powerdynamo online shop, are they the same, they look to be the same kit.
https://www.powerdynamo.de/shop/sho..._id=325&SESS=kuob44kkftbef2gb2emo6ajaue0oejto

I can get this less the tax + shipping for 230Euro, about $300 australian, which is well under anything else, is anyone here running this or may have dealt with this company. I am dying to get it going again, the noise and vibrations are just so good, have owned my 240 for 20years and it will be next to be repaired.

Just got a shipping quote of 130.00 Euro, yes $175 to ship a 1kg package, there has to be a better option, I dont want to go moplat as I dont think they are any better, just more parts around.

Does anyone know if this kit will fit my bike, not much info on the site about models etc, is a medium shaft 250.
http://www.electrexworld.co.uk/cgi-...D=wr250&PN=STK-019.html#aSTK_2d019#aSTK_2d019

Is anyone here running these units? I dont need lights, just want a spark.

Hey guy's I just came across a Barn Find just like this one it's an 86 Wr250 But the the Guy that owns it Tell's me that it has two issues one being No spark the 2nd is what I am told is a ring issue? The Bike is in Great shape but from the looks of the issues you are having Chris I don't know if I dare? Love these old machine's though!! But is it worth the time and money?? Sorry to but in on your post...

Motoplat's really don't have any issues. None to orry about. So if you're looking for a cheap reliable route go that way. If you want things to be perfect and never ever give you a problem go with the MZB.

Never heard of the one from electrexworld and not giving models it fits on is very vauge and it most likely won't fit your bike. There's a saying that goes universal products fit nothing in the universe.

Hi again,

Thats what I was thinking, not enough info to spend that amount of $$$ on one,
I have tried to find a decent photo of a sem stator installed in a bike, I have looked at mine till I am blue in the face but cant for the life of me get the stator in a position where it should line up.

The base plate for the stator I have is a 2 piece unit, larger outer ring with 3 mounting slots to mount to the crank case. it has MADE IN SWEDEN and part number 1614165 cast into it. it can only fit one way into the crank case, as there is a relief cast into the plate to match up with a cast crank web in the case. there is a smaller inner plate which mounts with 3 screws also to the outer, it has a "cut-out" in it which matches up to a cut-out in the outer ring to allow the stator wires to pass through, so it can only mount in one position.

The stator, both of the ones I have, only fit the inner plate one way, the mounting screws (3 of) are offset so 2 are closer together, which stops the stator going on the plate in the wrong spot.

Now the questions I have, when the flywheel is fitted on keyway, and engine wound to TDC, or just before, the "timing hole" in the flywheel is pointing towards about 5 oclock, (just right of vertical), as shown in several manuals for the lat 80's bikes, but when assembled, the stator, with timing line marked in the smaller coil winding, which I imagine is the trigger winding, is pointing at about 11 oclock, or almost 180 degree out, I have tried every combination of plates etc, but the stator cannot be mounted so the trigger winding is pointing down anywhere near where the flywheel timing mark is.

What has me confused is, I marked everything before I removed, the plates to each other, the base to the case, the stator to the base, but it is all wrong now, the bike was running fine, I had raced it, started frst kick, every time, now no matter what I do, no spark, I have tried every combination of parts I have, no spark.

I powered up the coil with the CCFL inverter again, it feeds a steady 250V ac into the coil, winding over with kick starter see's a HUGE spark, but the timing is out about 170 deg so it kicks back like a mule, flames out the carb and muffler etc, so I know the trigger winding is firing the coil, but why cant I get he timing right, when it is set-up just how it was when running before.

The keyway in the crank is pointing almost straight up with the hole with arrow almost straight down when on TDC, the trigger winding/coil is also point almost straight up.

I would love a photo of a SEM coil installed in a case, and a decent photo of a sem flywheel in the tdc position, just so I know I am not going insane.

I am waiting to hear back on freight for the powerdynamo unit from CZ, I cant find anyone who stocks the MZB unit, penton wont sell to public, no one socks them.

Would anyone have a part number for a moplat flywheel, stator etc that would suit ths engine, it is a 250 with the 13mm crank (small or medium) depending on which site you look at.

A parts book or lead to one would be great, I just want to get it going.

Thanks again.

I'll start by saying that if you marked everything when you took it apart and it was all in the correct position and now it won't assemble correctly it's not the parts. Your procedure is wrong and you're missing something. Are you sure you're setting the piston up at the proper degrees BTDC? Almost sounds like you're setting the timing up for TDC while it's a BDC so once it reaches TDC it's about 180 degrees out. Just a thought to double check that or maybe even completely start over and be very methodical.

Why don't you just set up the piston @ the proper degrees BTDC and make the timing mark on the flywheel sit at 5 and see what happens? Don't worry about the coil windings or anything. Just to see what happens do that. Just trying to throw ideas out there.

I do have a parts listing for the bike. I'll try to get the PN of the motoplat PN's for you.

Ok, in the parts breakdown they do not give individual PNs for the components. They list it as an assembly.

So the motoplat assembly PN for your 250WR is 16-14-801-01

In the parts breakdown you are number 31

If you need the exact procedure per the manual I have it. Just let me know.

Hi again,

Thanks so very much for the info, the parts assem 30 as shown in part list is what I have, the two piece plate etc.

I am setting the piston at 2mm beofre TDC, the piston comes up, once it reachs TDC on indicator, the indicator is zeroed out, then engine wound through again until it is 2 mm BTDC, the flywheel hole with arrow is about half way between horizontal at 3 oclock, and vertical at 6 oclock, (pointing towars the bottom LSH of case.

I cant see how I could mount the stator in a way to get it to fit with the timing line anywhere near that position, it points almost vertical up, towards 11 oclock, almost 180 out.

I would love to see a munual that has any info on setting these up, all I can find is one that says to mark every thing and line up the timing mark through the flywheel, there is only one "mark on my stator, it is a long narrow groove, directly above the small trigger winding on the stator pack, I will find a photo and mark it.

This photo shows the same stator as mine, with timing line pointed out, Is this where the flywheel arrow should be pointing at the correct BTDC point of crank rotation?


This photo shows approx where my flywheel sits at BTDC, the stator howver is 180 deg out, pointing towards 11 oclock
http://www.cafehusky.com/data/attachments/9/9738-8d0be850c0ffbe916167a28b5839c1c8.jpg

This photo shows the same flywheel, stator and coil, the hole with arrow is the one I am using to try and time, it is the one that points to 5 oclock.
http://hva-factory.com/images/SEM Amal.JPG

I am at the point where I may take the key out of the crank and mount the flywheel timed to the stator and see what happens.

I got a reply from Powerdynamo re frieght, they will do shipping for 45 euro on DHL shipping, so a total of 272 euro shipped ($365 au), which is less than I can get a stator rewound for, I could then sell the new bits I have on ebay, and all this would be over, but I know this thing has to run with the parts I have, just makes me wonder why It is so far out.

The stator I have came of a late KTM, I wonder if direction of rotation would make any difference, to look at they are the same, but maybe the trigger coil is set up to go the other way? just trying to eliminate causes.

I think I will order a new unit, but would love to get to the bottom of the cause, any Aussies out here with spares who want to sell / lend / help, I am going to pull the flywheel on mky 240 over the weekend and see how it is set up, timed etc. it has the same ignition.

Thanks again for help.

Thanks John, but yes, the Kill switch was the first thing unplugged, bloody sparks must have all leaked out, cant find them anywhere.

The strange part to me is that the bike ran with these same components?

There are several different models of external flywheel SEM ignition - SOME used the "hole with pointer" lined up with a timing mark on the stator... BUT... the timing mark is actually a series of degree markings on the wider flat part (marked "charging coil red" in your first photo)... 180 out from the single mark on the narrow part of the trigger surface. If your stator doesn't have the "degree field" on that surface, it wasn't designed to time that way.

You see in the HVA-factory picture above there is a tiny ~1mm pin hole right next to the larger "hole with pointer?" There is a timing pin that goes through that hole and mates into the timing groove on the stator - seen in your photo as a slightly U-shaped relief at the edge of the trigger surface of the stator, upper right in the photo.

YOU HAVE TO HAVE A FLYWHEEL WITH PIN HOLE AND STATOR WITH PIN HOLE TO TIME WITH PIN.

Now, if you DON'T have that tiny hole in your flywheel, you can't time with a pin, obviously. And, if somebody mixed-and-matched a stator and flywheel that are NOT originally designed to work together... well then you've got a problem. Various model bikes DID have the keyway slot in different clock positions, and then all bets are off. KTM DID use a counter-clockwise SEM stator on the bikes with a left side flywheel, and a clockwise stator on their bikes with a right side flywheel (like your Husky). If a guy really knows what to do, you CAN set your own marks and make a piecemeal system work... but you have to know what you've got and where the needed alignments have to be.

I have an 83 husky 250WR running an original SEM and I'd be HAPPY to send you any photos needed, but it could not be till early next week due to work. I also have many Husky and KTM orphan spare cores that we could photograph and help you find your problem. For starters, many SEM flywheels supplied to Husky had the "Husky gunsight" logo cast right into the surface. Not necessarily, but many. Do you have that?

Here is a very bad photo of an SEM on my greasy old test mule (trying a PWK carb and WP USD forks).
Notice the "H"...

Here, I found a better angle in the photo album. You can see Husky "H" and "hole with pointer"... but notice that there is NO PIN HOLE. This is an 81 430 XC designed to time by "pointer and degree-field" method. It is probably NOT in timing position in this photo. It's lying wherever it stopped when I shut it off.

Not familiar with SEM ignition but I do know that the timing specs for an 87 250 wr, ignition adv on piston is
.051mm BTDC. 2.0mm would be for a 86 400wr, according to my book. If that helps. I also have the orginal Owners manual for the 88 250 wr that has a small section on the SEM ignition

WOW, so much info.

It looks like it should be right then, from the above manual it states the line on the stator will be 180 degree oposite, which is where mine is, so it looks like I may have an issue with Stator being from a KTM, the one I got it from has the stator on the Right, like the Husky, but is mounted in the cover, so it is set for oposite direction rotation, I think this may be my problem, I will put my old stator back in, which has non functioning Coil charge windings, but the trigger winding is OK and power the coil with the CCFL inverter, se if the timing is OK there.

If it is, I then just need a funtioning Husky RHS clockwise rotation stator,

Thanks so much everyone for the help, trying to track down this stuff takes so much time as you know.

I will be buying a aftermarket system, but I need one for the 1986 wr240 in the shed, so it wont hurt to have spares.

I will let you all know how I go, I would buy any old Husky if it a fair price and nice, I can solve this all for $360 Au shipped, but trying to get to the bottom of issue too, not just throw it in the 2 hard pile, maybe we can all learn.

Rings in a 2 stroke are nothing, easy. dont let it scare you, grab it and sort it out later, I would if I come accross one for sale.

I am after a late twin shock 400+ cc 2 Stoke either CR or WR, dont mind either, or a late auto, 390cc + in size, have an OK to good budget, but not been able to locate any just yet.

Chris, I believe I have most of a SEM ignition off an 84 250WR, that was running when I parked it a few years ago. You can have it, if you think it will help.
Ron