Snowmobile engine (no spark)

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  #1  
Old 06-19-05, 09:15 PM
crazybiker51
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Snowmobile engine (no spark)

Hello, i have a 1990 yamaha ovation snowmobile engine (just engine) and it has no spark. It never came with a coil so i bought a new one, and i also bought a switch to use for killing it, and to complete the circuit. The red wire for the coil has a voltage reading, but when connected to the ignition coil there is no spark reading (not a faulty coil, i have sent it away for testing already) there are 3 wires comming out, 1 red, brown and white, the red i take it is for the coil, while the brown is for a ground, and the white probually is for a kill switch, but there are 3 other wires comming out, and go to a three prong adaptor thing, i'm guessing this is for lights, but would i need to have it connected up to complete a circuit? my teacher thinks that those are seperate and dont matter. I have cleaned the flywheel magnets etc, but when it turns over i have no spark at all, any help would be great, thanks alot.
 
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  #2  
Old 06-21-05, 10:41 AM
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even though you probably already have i have to say it because there are those people that think to far out of the box instead of checking inside first.....check the spark plug, take it out and turn the engine over. check that it is not fouled in anyway and that it has good connection with the wire. just had to say it...
 
  #3  
Old 06-22-05, 10:33 AM
crazybiker51
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Thanks for your reply, the sparkplugs are so clean they look new, we took the engine apart to clean it, and there was'nt much to clean, the engine mabey has a season of riding on it, in the float bowl, there was one small spot that had discolouration on it, i have tested all of the wires and they all have readings, i dont know how high their supposed to be, but they all have a current.
Thanks for you're help
 
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Old 07-24-05, 05:38 PM
crazybiker51
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anyone?
 
  #5  
Old 07-27-05, 02:21 PM
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no spark

You gave some good info, I am not to familair with that model,

However, If you had the coil tested and so forth, did you check the brain box, the ignition box checked ?

another thing, check for a load on the wires,, check the on/ off switch they go bad, could more than likely be a ground wire issue.

What you need is a wiring diagram for the snowmobile, i have seen red not always be the hot wire, i have seen the brown wire also be a hot wire.

And if you connect it wrong and try it, its easy to fry the ignioton box

sporty
 
  #6  
Old 07-28-05, 05:18 PM
crazybiker51
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Thanks for your reply, i do not have a cdi unit, or a key ignition type setup, the engine is bare, i've been told i dont need a cdi unit, because it just connects to the key, i have also been told on a snowmobile engine, that you do not need the key thing, you just by-pass the whole thing, but im lost, and have no-clue what to do with this.
Ps, i have made a toggle switch into an ignition switch, and have tried all configurations but no dice.
 
  #7  
Old 07-29-05, 10:41 PM
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Hmmm,

There should be a module on the engine some where, this is gonna provide the spark, connects to the coils, then should be some other wires that run to the switch.

I believe a sled is a 3 prong switch, if you are using a 2 prong, maybe that is something to look at. How are you grounding the unit ? have it grounded to the go-kart ?

Since you said that some of the parts were new and checked out, no spark, im thinking a connection issue of either positive not being connected or grouding out somewhere.

sporty
 
  #8  
Old 07-31-05, 07:30 PM
crazybiker51
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There is supposed to be a cdi unit on it, but people on a snowmobile site said i would'nt need one, i bought new plugs today just to see the obvious, but they never worked
Heres a link to a schematics page by the way:
http://216.37.204.202/Yamaha_OEM/Yam...pe=13&A=8&B=36
at the top, left of that picture, it's the first set of 3 wires, and the light assembly, i guess i might need one of those to connect to, then plug that in to the cdi unit, and then from that cdi unit, that one wire connects to the coil? i have no clue at the moment, and if i did buy that wire assembly, i wonder if i would need all of the others connected up to make a complete circuit? But then where would that coil hook up to? wow im confused
 
  #9  
Old 08-02-05, 10:41 AM
crazybiker51
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http://cgi.ebay.com/ebaymotors/ws/eB...ategory=100456
SO i have figured out eventually that i WILL need a wire harness and a cdi unit, will i need a switch assembly also? if you look at the harness at the top, the first set of 3 wires and the light unit thing, plug into the only wires on my engine, im guessing that that wire harness then heads to the cdi unit, am i correct? no-wonder it wont spark, the wire harness is supposed to plug into the wires, then my coil into the cdi? thats what my guess is after 6 hours of staring at that picture, and looking on the net, anyhelp would be very helpful, i want to keep this engine, and only have to buy those parts, because i have been debating a new engine lately, but after relizing my engine is in mint shape, i might as well keep working on it, and risking a bit.

PS:What is #3? RECTIFIER & REGULATOR ASSEMBLY, what exactly does this do? and will i need it for my go-cart application?
 
  #10  
Old 08-07-05, 12:17 AM
crazybiker51
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i have been told i dont need the regulator, it's just so you dont blow the lights, but heres an update, i went to order all the stuff, the cdi was $121, not bad (canadian) but yamaha doesn't make the wiring harness anymore, so im pretty much screwed over, does anyone know of a place or person that would have one?
 
  #11  
Old 08-07-05, 12:18 PM
jeffstevens
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How bad are the wires? a new CDI comes with a pigtail (wires) you can splice in.
 
  #12  
Old 08-07-05, 08:57 PM
crazybiker51
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which wires? the ones comming out of the engine? thats all i have right now, no wiring harness, the only electrical are the wires comming out of the stator, which plug into the wiring harness, which then plugs into the cdi i guess.
 
  #13  
Old 08-07-05, 09:05 PM
jeffstevens
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Check the new cdi unit at a sled shop, I'm sure there is wires for it. If not you can pick up a terminal kit, crimp on the wires and plug them in to the pins. You may need a schematic for the right configuration.
Originally Posted by crazybiker51
which wires? the ones comming out of the engine? thats all i have right now, no wiring harness, the only electrical are the wires comming out of the stator, which plug into the wiring harness, which then plugs into the cdi i guess.
 
  #14  
Old 08-09-05, 09:39 AM
crazybiker51
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i finally found the same engine thats on an older not working sled on ebay, i was jumping when i saw it, so im bidding on it, and i will be able to buy all the parts i need off of it, secondary clutch just so i dont need a belt to the axel, the exaust pipe, fuel tanks etc, if that doesn't work, i will just buy the cdi unit, because when i think about it, the wires i have just plug into the wiring harness, and im pretty sure the wire harness plugs into the cdi box, but it could get complicated, so we'll see what happends, thanks alot, keep posting
 
  #15  
Old 10-10-05, 03:07 PM
crazybiker51
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I ordered a new cdi, and it will be here tomorrow, however, i will need a wire harness, is it possible to make one? my metal teacher said i could, but i'll need help with this idea, seeing as i cant just buy a wire harness.

By the way, the ebay one would have been PERFECT, cheaper then just one part, and i'd get it all, but of course i had to go out for the day, and lost the auction by $1
 
  #16  
Old 11-11-05, 07:13 PM
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crazy,I do not know where you live but if you can get to a used parts place that deals in sleds,you will likely be able to pick somebodies brain for the price of a large coffee.I know of two places that you could go to.....if you could get to Oshawa or Peterborough.Be very careful if you are buying used electrical parts,they usually come with no chance for return,make sure they work BEFORE you leave there building.good luck
 
  #17  
Old 11-28-05, 07:59 AM
crazybiker51
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thanks, there aren't many salvage yards around here, i live in BC too! but oh well, i bought a new one for $130 bones it sat there for a few months, till i descided to chop off the two male connectors where the wire harness is supposed to go in between, hooked it up, and i have spark, it runs nicely, i thank you all for the help. I am making a ram air system for a cone style filter right now but i need to figure out fuel and all, it has no fuel pump, but it should, well it should have alot of things... instead of using the oil pump, i think i'll have a tank of mixed above the carb? it should automatically feed down when needed right? oh well, all the small things left on my go cart now, need to mount the engine, find some front wheels, then figure out steering, and brakes, should be done by january i hope, it was a fun high school project, and i cant wait to drive it.
 
  #18  
Old 08-29-08, 10:02 AM
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Hey Crazybiker51
can you please, please email me at [email protected]
i have the same engine as you do and i am having problems with it.please email me
 
  #19  
Old 08-31-08, 09:20 PM
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Ignition has quite a few more components that the ones you spoke of.

First off, there is the flywheel. This provides POWER for the CDI via a large coil. Also under the flywheel is the PICKUP coil. There may be several pickup coils for multi cylinder 2-stroke engines.
I've seen designs where they fire all the spark plugs at once. This is good up to 3 cylinders.
There is also a key between the drive-shaft and the flywheel. If this is not right, it won't work. I've seen folks remove the key to advance the timing for a race - then forget to put it back afterwards.

Second, there is the CDI. This allows the 'Kill' switch to shut down the engine. It energizes/deenergizes the coil at the right angular engine moment to cause a spark at the correct time. It also prevents the engine from revving too high (rev limiter).

Third, there is the coil. This inductor takes a low voltage/high current surge, and converts it to a High Voltage - low current spike. Put this across a gap and you get a spark.

Fourth, there is a distributor. You may not find these on a snowmobile, but probably will on car/truck/boat/cycle with 4 or more cylinders.

Fifth, are the spark plug wires. These will go bad over time. Heat/Vibration can also destroy them. They are thick insulated rubber cables with a thin wire in the center. They can carry up to 75,000 volts. If you get shocked by touching the outer casing - they need replaced.

Sixth, are the Spark Plugs. Business end of the whole system. They are subject to contaminants, physical breakage, and wear out over time. You must select the right size, heat range, and adjust gap for your specific engine. Most folks don't know that it takes MORE to spark a plug when installed in the cylinder with gas/air mixture. If you have a weak spark outside the cylinder - you probably have none inside.

Biggest problem I see here is that you've never had a working system. This is a science project. Have fun working with this high voltage stuff.

Keep playing until a shock knocks you across the room - then you'll have a working system.
 
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