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Discussion Starter #1
Hi
Hoping someone can shedd some light on my issue.
I have a 2009 vstar 650, with about 10k miles. Its been sitting all winter. Tried to start it a couple weeks ago, no spark. I tested the pickup coil which showed dead so i got a new one from ebay.
After replacing the stator and pickup coil this morning, the bike starts, but runs rough and backfires a lot thru the exhaust. Almost acts as if the timing is off.
Could the positioning of the stator affect the timing? Does it have to be installed in a specific position?
Could the carbs be fouled up from sitting all winter? I did put fresh gas in the tank, but i'm thinking the carbs could still have sludge built up.
Would that cause the backfiring? Also, the bike only runs if throttle is applied or if the choke is on, otherwise it will die.
thanks in advance for any suggestions!!
 

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Yes, positioning of the stator controls the ignition timing. When the rotor magnet passes the pickup coil it generates the pulse which, via the electronics, fires the spark. If the pickup coil is incorrectly positioned the spark will fire at the wrong time.
 

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Discussion Starter #3
thanks for the reply, that makes sense. But i didn't notice any timing marks or anything like that on the stator. I also checked some of the posts and didn't see anything.
Do you happen to know how the stator needs to be positioned? or point me to a web site that shows that?

thanks!!!
 

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I don't know your bike specifically, since I don't have one like it. I'd be surprised if the stator could be mounted incorrectly unless is possible to fit it into say, three positions with three symmetrically placed mounting screws. It is also possible that different model years used different stators, along with different rotors with the magnets in different locations, but that is only a guess.
 

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Discussion Starter #5
i went ahead and took the carbs off and cleaned them, but that didn't help a bit.
I guess my next step is to take the crank cover back off and figure out what the heck could be wrong.
Any suggestions on the positioning of the stator or pickup coil would be great!.
 

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Discussion Starter #6
Hello again. I havent had much time to mess with the bike until this past weekend. I swapped the plugs and the coils, back to front, with no luck.
I did notice something i had not noticed before.
When the engine is running, only the front cylinder gets warm, the back one stays cold to the touch. Also, I noticed that the backfiring and flames only come out of the back cylinders exhaust pipe.
If I unplug the back cylinders spark plug wire, the motor runs much better, no more backfiring, although its only running on 1 cylinder.
If i unplug the front plug wire (with the back plug wire plugged in), the motor will not start. This happens with the coils and plugs swapped.
I checked and double checked the cams timing, all marks line up.
Is there something between the stator and the ignition coils that controls the spark timing? could my stator be defective? if so wouldn't it affect both cylinders? i'm at a loss...about to give up and take it to the dealer...any suggestion would be much appreciated.
 

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Discussion Starter #8
ouch!!! how can i check that without pulling the head? if i remove the valve adjustment cover and rotate the engine?
 

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Run a compression check on the motor. No compression (or real low compression) means you have a problem. It's possible that a valve could be stuck partially open and not hit the piston.
 

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Re-reading your first post, I see you got the replacement part from E-bay. Are you absolutely certain you got the right part?
 

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Discussion Starter #12
Yeah, i got it from ebay for about $100. It came in a blank box, so i dont even know what brand it is. So no, i'm not sure its the right part, other then it does look exactly like the original.
I'm thinking maybe some of the coils on the stator are bad? but i wanted to exhaust all other possibilities before forking out the $300 the dealer wants for a new one.
I'll run a compression test this weekend...keep your fingers crossed for me :)
If the compression test is good, i'll order a new stator from the dealer.
 

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Your description sounds as if the engine is running only on the front cylinder, and the back cylinder is way out of time. The fire out the rear cylinder exhaust makes it seem as if the cylinder is getting fuel, but the fuel is being ignited only after the exhaust valve has opened. Is there any chance you mounted the replacement stator half-a-turn away from where it should be?
 

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Discussion Starter #14
yep thats exactly what it sounds like.
I did take the crank cover back off a few weeks ago to see if the stator was mounted wrong. There are no marks or anything that indicate how it should be mounted.
As far as i could tell, i mounted it the only way possible due to the length of the wires.
So the position of the stator controls when the plugs for each cylinder fire?
 

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I think you are going to have to get hold of a service manual, whether Yamaha or Clymer, and look for a picture. If you are on good terms with the people at your dealership, the guys at the service desk may let you look at their manual. When I asked about valve adjustment procedure on mine, they downloaded and printed the appropriate pages for me. It is also possible a local library might have some sort of manual you could check out. At worst, you haven;t lost much by asking.
 

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I'm having a very similar problem and am stumped. Had a starting problem, diagnosed at local shop as bad stator. They replaced it. Right away I noticed a little backfiring which got worse and worse. Now all of a sudden when the bike is good and hot and running strong, it starts to feel like the engine is cutting out. This happens on and off, but especially when at the top end of a gear ready to shift up to the next gear. The final straw is when I come to a stop (or am coasting to a stop with the clutch pulled in) and it stalls. It starts right up again, though. I've also pulled and cleaned the jets (both sides), replaced the fuel filter and sprayed carb cleaner up the intake.

I am riding a 2011 Yamaha V Star Custom 650. I am essentially the only owner - bought it with 1700 miles on it less than 2 years ago and it only has 11,700 on it. I've maintained it faithfully, though it did sit for 3 months at the shop during stator replacement because I'd been in a car accident and couldn't ride. Still, after picking up the bike I rode 300 miles the first day and 200+ the next and it performed fine, although it was backfiring a bit. It was a week later, after commuting 60 miles per day with it, that the "engine cutting out" stuff started to happen.

I would LOVE to know if you have discovered what is wrong with your bike, since it is probably what is wrong with mine!!!
 

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Discussion Starter #17
H RedBaron
I haven't done anything to my bike since the last post. At this point, i suspect the stator/pick up coil i got from ebay is faulty and am planning on getting one from yamaha, although they don't come cheap.
Do you know what brand your new one is? your problem does sound like yours is going bad as well, from other posts i've read.
As far as I know, there is no other electrical part between the stator and the coils that regulates the spark timing.
Once I get the new stator and install it, i'll update the thread.
 

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Hi Viken69,

It is an Electrosport stator. I'm really stumped. The bike presented in Feburary with a starting problem: would crank but would not turn over. Full power, air, fuel and spark. So the shop diagnosed it as a bad sensor on the crankshaft. Since you can't replace just the sensor because it is integrated in the stator, they replaced the stator with the Electrosport.

Granted, the bike sat from late March to June due to me being injured in a car accident and unable to ride. But the shop had looked at the carb and said they weren't gummed, which is why they moved onto checking electrical.

Both jets on both carbs have been freshly cleaned, the fuel filter replaced, I have had no "bad gas" issues, ran it with seafoam just in case, had fresh spark plugs put in about 8 months ago and the air filter is OK. A little dirty, but that is because it does its job.

When I got the bike back I noticed a bit of backfire sound and the first day I had it out warming in the driveway it stalled after 5 minutes of warming. Weird. Rode 500+ miles without incident the next 2 days and then commuted 60 miles round trip to work the following week, again without incident, until that Friday. That's when, on the way home, it started to buck and seemed like it would stall at 50 mph on the highway with throttle engaged. It seems to run well when cool, but when outside temps are hot and/or the bike gets really hot, the bucking and stalling begins.

I HATE doing anything electrical with motos. In my experience it is hard to get it just right. I've had problems when having professionally installed after-market kuryakyn bullet spots. So I don't eff with electrical. In this case, I had no choice.

So once I get the story from the shop I'll update this thread, too. Very, very frustrating. Lost 3 months to getting hit by an idiot driver and my riding season is disappearing while my bike spends weeks in the shop. I'm ready to trade her up to something fuel-injected and liquid cooled, but I can't get her running right long enough to do so!

So everyone...stay tuned. Viken69 and I will post updates as we have them!

RedBaronRider
Dog is my Copilot

https://drive.google.com/file/d/0B-ynW4fXCH7US3RCS01McFdvZE0/edit?usp=sharing
 

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Red, you said that your issue seems to happen when the outside and or bike temps are high. Maybe your issue is more fuel related. Could be your experiencing a vapour lock or your cap is not venting properly. If the mechanics say that they don't see anything wrong, ask them if they thought of this.
 

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Thanks Corsair! I spoke with the mechanic today. He suggested it was vapor lock, too. But this is nuts. I can only ride it 20 miles in the heat before it vapor locks? Unacceptable. There is some research to support that the after market stators are not very robust. See link below.

Basically, I am a daily commuter on my moto (60 miles) as well as 200 - 500 miles most weekends, and of course, a couple of epic motorcycle vacations per year (2K or so miles). I can't have a bike that stalls out and has an "undiagnosable" issue. If she runs ok when cool, then she's going to a dealership as a trade in :-(

Here is a link with info about stator and pickup coil issues: http://ziariderblog.com/2012/05/electrosport-stator-failure/

Cheers, and thanks!

RedBaronRider
 
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