I have no spark, now what??

mrviper700

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If you have no spark in your sled theres no reason to panick :whine: . A very common issue with a "no spark" situation is when the sled is trying to be first started for the new year, it has likely sat in a enclosed trailer or shed with less then adequate ventilation and that causes condensation. Condensation causes rust! So first and foremost if it ran last year and doesnt run now, the first place of suspect is a rusty flywheel.

1.) observe down on top of the recoil housing a small hole, shine a small light in there and see if the flywheel is all rusty. If it is, youll need to remove the recoil housing. Then take a small peice of sandpaper and sand the magnets located on the outside of the flywheel. These magnets are what passes by the pick up coil and that sends the signal to the cdi box. You can then use some brake clean or spray to clean the flywheel and immediate area, blow dry with compressed air. I always give them a little dusting of wd40 or kroil lube-lightly! Reinstall the recoil housing. Check for spark now, this is a very common problem and fix.

2.)If you still do NOT have spark then youll need to eliminate a few possible causes. You can do ohm checks on the kill switch, check it while turning it on and off, youll see it change on your meter if its working correctly. Also check for a tether switch... these are known to cause problems with less then ideal installations and wiring jobs. Alot of times someone adds on and forgets and the wiring they did is what causes the problems as your in the exact same circuit as to what shuts off the sled, the ground for the cdi box. if there is a tether switch on the sled, take off the cord and take a small penlight screwdriver and press in on the plunger, check for spark, sometimes the plunger doesnt make good contact inside the switch. Most of the key switchs are easily removed from the puzzle by simply unplugging them, (this applys to the 175 watt single bulb sleds,98-99 srx,etc.) on the 2000-02 dual bulb sleds with 3d ign. you need to jump the brown to red wire..... check for spark now.

3.)So now lets say you still dont have spark..., how do you know if its the stator,cdi,coil, or wiring harness rub thru failure?? You need to start at the source of the power and work out. This means checking the power output of the pick up coil, the same coil that reads those magnets on the flywheel we looked at earlier. There is ohm checks for this in the service manuls and they work but I will tell you right up front you cant take that ohm check to the bank as its only as accurate as the air temp is its checked at and the quality of the multi meter your using. My fluke multi meter is going to to give you a differnt reading then your harbor freight model is, so I am not saying they cant be "usefull" but I wouldnt say its the only check to perform.
I like to use a dynamic check and test the voltage output of the parts as you pull the engine over and see whats happening. The pick up coil will send vaying voltage to the cdi box, so we need to hook up the meter to the pick up coil wires, give the engine a nice pull on the recoil rope and see what the voltage is. It needs to be around 1-2 volts(also matters on what scale you use on your meter, may be like .8-.9 volts on your meter) minimium for the coil to send enough power to the cdi box. When you pull over the recoil the p/u coil should show you varying voltage as its dependant on how fast you pull the engine over.
If you have power coming from the p/u coil then again check it at the entrance of the cdi box to eliminate the possibility of a broken or chaffed wire, if the same move to the output side of the cdi box, this wire will run to the coil pack.
4.)ALOT of times it is indeed the p/u coil that fails, the thing is.. yamaha only sells the p/u coil as an assembly with the whole stator. So you most likely will need to replace the stator assembly if the p/u coil is not giving you the voltage needed up to the cdi box.

5.)lets move to this part if your p/u coil IS producing good voltage output, Again... hook up to the wire going to the coil pack, from the cdi box, do you have greater voltage yet when pulling over the sled? If so then go down to coil pack agin checking for a broken wire if still no spark. If your good down at the coil then you need to check your coils for continuity and also test your spark plug caps. The yamaha caps have little resistors in them and they do fail after a few thousand miles or alot of years of age. You will now be at the pint of a failed coil, because you have power all the way from the source to the coil, so ne reason it cant reach the plug,unless the coil is bad. Continuity checks and the ohm specs from yamaha are how you will be able to check the coils.

lastly...Dont get so frustrated you start throwing parts at it to fix it. With a little patience and testing you can zero right in on the failed componet thats causing your grief, you just have to follow the path of the power from start to finish.
 
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Great post...very timely as well as these Yamaha 2 strokes aren't getting any younger as the amount of people recently having "No Spark" issues can attest to.

Bob
 
Awesome post ... could have used this info just last week!!! LOL!!! I'm sure I speak for many, THANK YOU AGAIN for sharing your knowledge, CHEERS CHRIS.
 
So how exactly do you check the ohm reading of the spark plug caps? Do they come off the coil wire?
 
Yea I did a search and found that. Tested all caps and they all came out to about 5.5k
 
Got a head scratcher here...or at least think I do. Went to fire up an 01 srx the other day. Has sat in enclosed trailer all summer. Key switch wouldnt turn, acted like it was the wrong key. I THAUGHT unplugging key assembly sled should fire...right? Didnt, pulled plug wire off and no spark. Didnt dig into why. Removed key switch and stuck it in my coat pocket and fired up the other sleds. Later that night (after hanging coat up by wood stove) I grabbed the key assembly out of coat pocket and key turns just fine now! (thinking a little condensation had frozen in tumblers?) Plug assmbly back in today and had spark????? Unplugged it again...no spark???? Shouldnt an 01 have spark with key unplugged? Or is that wrong?
 
Don
Hey what if you get 1 spark and then nothing. turn key off and back on and 1 spark again. Its my stepsons 96 600 giving me problems. Thanks Paul
 
no spark on an o1 with key unpluged just went through this 2 nites ago and had 2 prove it to a friend he was pissy
 
yamadogg said:
no spark on an o1 with key unpluged just went through this 2 nites ago and had 2 prove it to a friend he was pissy

WEIRD...I have seen a newer viper run with key unplugged but an 01 srx doesnt? at least now I know I dont have some other weird wiring problem ;)! Thanks for verification!
 
98-99 srx will spark with no key switch, the 2000-02 srx wont, it has a differnt wire to complete circuit, youll need to jump the 2 wires on the 3d ign. system,(brown to red) still easy enough to eliminate the problem. I write these off the top of my head hard to remember every sled wiring combos in the mix when you get old....lol

i will address post so it reads right.

add: viper- needs brown to red/yellow tracer jumped to run without key switch.
 
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I am having an issue, my mm700 had its wire harness going to the coils melt.
It took me home, it ran great but the next morning, no start, no spark.
I noticed the harness was close to the exhaust and it melted at the 4 wire connect that feeds the coils and yeah I had no spark
I rewired the harness and still no spark.
Could the cdi have died as a result of the wires melting together?
Where can I find a wire diagram for this 2001 mm700?

thanks for any and all help
Chris
 


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