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Yes....the crank sensor tests in the service manual would be for resistance then cranking voltage. Did the PO by chance replace the stator? They come with crank sensors and there can be issues if the sensor is just a little different than what it had. I ran into this with my bike and new stator....it would try to start, pop and backfire here and there but not run. The crank sensor on the new stator checked OK resistance wise, but it was a bit too far from the reluctor teeth to generate a proper signal for the ECM.
 

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Discussion Starter #22
my next step then is to obtain a service manual and go thru it. i know for a fact that he did not change the stator
we had a long conversation about what he tried and symptoms he experienced and i believe he was honest with the info he forwarded to me. im getting a little anxious to get this issue resolved as i can remember how nice a ride the SV was when i first owned it. i came off an 03 R6 to the sV and i found the sv more fun to ride. and the sound was amazing with that chopped and gutted Yosh trioval! iq picked up a mint Vmax acouple days ago so im having fun with that but im looking forward to bringing the sv back on line again
 

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The service manual for your bike is available for (free) download. Just google it, or search these pages for a link.

Good fortune,

Alan


Sent from my iPad using Tapatalk
 

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Discussion Starter #24
i have ruled out the stator and i believe the ckp. i Learned how to use my meter effectively and test the various parts and pieces. however: my uncle, who is an automotive mechanic, heard the bike rurn over and noted that it sounds like it may be off timing. and now that i hear that i tend to agree that it is a possibility. when i hit the starter with the battery on boost the bike seems.to struggle. to get over that first revolution. maybe timing. i dont know for sure of course but it is worth asking a few questions about it. if the bike is off timing qhat would be the most likelyculprit? it has about 20000kms which is about 12500 miles. i highly doubt it has had a valve check. it was damaged when fairly new, i rebuilt and used it and sold it, and by the look of it he subsequent owner did not take much care of it. so could valve clearance cause this? i guess i should know this but i really just want to hear from you guys with alot more SV experience than i do. and whils thinking about lack of maintenance would any other issues arising from lack of it cause this? like i said previously the guy i bought it from said it did run even after it started acting up and not running properly. he said it would start and run and drive for maybe 5 minutes then shut down. im really wondering if i will ever get this figured out. btw i have checked all plugs and connections and all checks out. im stumped.
 

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... when i hit the starter with the battery on boost the bike seems.to struggle. to get over that first revolution. maybe timing.
That is most likely a dead or failed battery. When you say "on boost" do you mean the bike is connected to jumper-cables?

Timing is not causing the slow crank.

It is possible this problem is just a failed battery. Also check to be sure the battery terminals are clean and tight.
 

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Discussion Starter #26
i attsined more info tonight just by messing around a little. i took both plugsout and put each in the csp. i then held both close in 1 hsnd while i held onto the throttle side of the bar and pushed the starter. i found that while holding eeverything im this position i would get spark alot, tho not steady. however by touching the electrode end of the plugs together while hitting the starter and i got constant strong spark. and i could see that both plugs were making spark individually. i really dont know how to dicipher this info but im hoping someone among you guys might. in fact im counting on it lol
 

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...by touching the electrode end of the plugs together while hitting the starter and i got constant strong spark. and i could see that both plugs were making spark individually.
When checking for spark be sure the plugs are laying on the cylinder heads making electrical contact.

There is no good electrical reason touching the plug electrodes together should improve spark. The plugs get ground through the engine, given the starter motor cranks (high current) means the ground is ok.

It could be a poor connection at the plug cap to high tension lead and moving the plugs in certain positions may be improving the connection.

Try unscrew the plug caps, cut 1/4" off the high-tension lead and screw back on. The plug cap to wire connection can be damage if not careful when removing the cap. Always pull on the plug cap, never the wire.

Good news, given strong consistent spark by moving the plugs around means the crank position senor and ECM are ok.


Question from the prior post:
... when i hit the starter with the battery on boost the bike seems.to struggle. to get over that first revolution. maybe timing.
That is most likely a dead or failed battery. When you say "on boost" do you mean the bike is connected to jumper-cables? If so, stop everything and get a fully charged healthy battery installed! Without a good battery you will chase your tail.
 

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Discussion Starter #28
well....i feel im getting closer! just a thought tho and its just something thats been on my mind since my post earlier tonight. would a bad ground or sme other connection be a cause for the plugs to spark when touched together? just brainstorming here
 

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Woody, buddy, you gotta read. The direct answer to your question is in the above post. The problem is not the ground, more likely a poor plug cap to coil wire connection.

Also, please answer the question at the end of the post.
 

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Discussion Starter #30
i actually did respond to the battery question earlier but it never posted. i might have not followed through with the posting process
yes the bike s hooked to a NEW battery. i ran out and bought a new one last week. i have a compact booster pack hooked up so as to keep the battery up whole turning it over. it reads out the volts of the battery when hooked up so as to show me if the battery voltage lowers and to assure me that the battery is providing sufficient power. i do think that there may be something to the cap thing. however the thing that makes me still wonder if it is the issue is that rhe po purchased 2 new oem replacements, caps and all and instslled them. after he installed them the same results wete produced so im just trying to play devils advocate here and generate some more ideas before i head back to the garage tomorrow evening. i will be focusing on the caps and wires and coils but ither suggestions dont go. astray
thanks for your suggestions.
 

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...yes the bike s hooked to a NEW battery.
Excellent. :thumbsup:

Based on information so far it appears:
- The battery is good. New. New batteries can fail out of the box but for now assuming good.
- Ground to the engine is good. Even if this connection were poor the starter motor would fail to crank long before the plugs fail to fire.
- Crank position sensor and ECM are good. Getting strong steady spark while playing only playing with the pulgs/wires means so those must be ok.

I share you skepticism about the plug cap connections given prior replacement. Even though we are running out of things to test, I think you are getting close. There is no voodoo no magic, the problem has to be there. :)
 

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Discussion Starter #32
i certainly agree its close. ive taken a day off today from work(my company) and i plan on having a go at it later today. thankfully this bike is not something i need in order to ride. thats what it was like i was young: get qn old bike and need to fix stuff before i could ride. these days i have a small collection of bikes allowing me to take all the time i need to fix this one. i am going to trim the wires today as well as recheck all of the connectors and such. thanks for all of your input teeriver and everybody else it is absolutely much appreciated.
 

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Discussion Starter #33
finally got the sob to run. took spart prettywelm every connector some forthe 3rd time and got a constant spark. as i turned on the jey i caught s smsll spark for the 2 wire plug on back. paid more attrntion to it tho it was clean. now i have a steady strong spark and it started. hoping this is it.
 

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Discussion Starter #34
sorry for all the posts but ypu guys know more than anybody what its like to chase the gremlins. i have the bike running and it runs nice and smooth. however it is very hard to start. i crank it over and it will take forever for it to make an offer. when it does i feather the throttle a bit and it catches. it runs smooth if i leave it however a couple things happen.
1. if i try to do any more than gently increase throttle it will shut down and it will start only after leaving it sit for 5 or 10 mins.
2. i can gently raise rpms up to around 7 to 8k and it will start to miss.
sounds like its not getting gas so i checked the lines, fuel pump kicks in. when i put a jumper wire in the test plug on the tail of the bike it shows "C00". when i get it started it throws out "C24" which is a fault for the number 1 cylinder which im guessing is front. i have a very strong spark on 5he rear but i could not see spark at all on the front. i have 2 more coils so i tried those, i changed caps, plugs and all same result. no spark. however when the bikes is running it seems as smooth as any other bike i have so im just friggin stumped about that. bright side is the bike runs somewhat. down side is it wont run anywhere enough to call it fixed. as well, i noticed when i try to put it in gear it shuts off. so there it is. im a bit farther ahead but not there yet. great paper weight l0l
 

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It sounds like there may be a few faults with this bike that may or may not be connected, well done for finding the first.
Code C24 would seem to be the ignition signal to the front cylinder, which corroborates what you are seeing.



So, I think you said above you had checked the coils and plug caps (but check them again), so what is left is the ECU and the wiring in between. I think the only way of checking the ECU is to swap it with another and see if the problems goes away. If you are able to borrow one try that, if not check all the wiring between with your meter - and wiggle everything around to see if that makes any difference. If you still can’t find the issue you may have to buy another ECU - a used one on eBay would seem to be sensible.
Persevere!
Alan


Sent from my iPad using Tapatalk
 

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Discussion Starter #36
this has certainly been an educational trek through the ignition system of the SV650! lol
I have always worked on bikes as that was initially the only way I could have one of my own. However I never really had to delve into the electrical system as with this bike, this never really developing an understanding of the whols circuit. Since I have been on this little adventure I have learned how to check contunuity, resistance, voltage and so on. I admitedly started this post a whole lot less knowledgeable on the subject than I am now which I believe is the positive that I will take away from this. I have come to the conclusion that the ecu is likely the cause of my bikes lack of spark on the coil serving the front cylinder. I spent the better part of last evening checking every wire, connector and everything else in the way for breaks, faults and so on. I could not find a damn thing wrong according to my newfound brilliance in these items lolol. Seriously tho after asking you guys all the questions i could think of I put in an honest effort at finally punpointing the issue. I dont want it tobe the case but looks like the ecu is kaput. so its off to ebay or wherever I can find a sensibly priced unit and try my luck. It was suggested that I borrow a knowingly good unit and swap it in. However most of my bike riding friends are moved from sportbikes to cruisers so borrowing is not an option. anyways thanks for allthe help and i will report later on down the road, when i get another ecu, if it eas indeed the problem.
 

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The SV ECM is extremely reliable. In ten years here on SV I have only seen a few gen2 ECM failures and all were of the fuel pump control, never the ignition.

That does not mean your ECM is okay but it should be the very last thing to replace.

Good thing is used SV ECMs are readily available and only about $50 so not a big risk to know for sure if that is the problem or not. Hopefully that will fix it.
 
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