Curvy Stator Issues. Bike cuts out
 

Hi there, I've been having some issues with my curvy recently. Battery died and bike wouldn't start a while back. Had a new battery in. Went well for a few months, until the bike cut out whilst riding. Electrics went first, then the bike begun to splutter until iflt finally stopped altogether.

After recharging the battery, I am able to start the bike but it dies very quickly afterwards in the same way as mentioned above.

I've replaced the RR as I had a spare lying about (also replaced the starter relay).

Battery voltage drops slightly when the bike is started, rather than 14ish volts that should be seen.

I have measured the resistances of my coils, all check out (around 0.5ohms).

I've also checked that my stator wires are not shorting to earth.

I was unable to run the bike long enough to get to 5000rpm to check the ac output from the stator, but while idling I was only getting 18v (supposedly 70 is required at 5000 rpm, not sure what reading is normal at idle).

I've also shorted my kickstand switch but the problem persists.

I am thinking that my stator needs replacing (only guessing, as I said before I'm not sure if my 18v was normal) , but before forking out on a new one I just want to see if there is anything else I can do, or if any one might have some other advice.

Any help would be very much appreciated!

Re: Curvy Stator Issues. Bike cuts out
 

I had a similar voltage issue last year, although mine didn't cut out, it just didn't charge the battery. As in your case, battery tested okay, r/r tested okay and stator tested okay, but low AC volts. When I took the stator cover off I found that the rotor magnets had either shattered, or were free floating [emoji50]
Not a common thing to happen...
I replaced the rotor with one from a breaker, and that solved that problem.
Unfortunately, shrapnel from the magnets later took out the oil pump, so that was the end of that.
Unless you've had the stator cover off recently you'll need a new gasket for re-assembly.

Re: Curvy Stator Issues. Bike cuts out
 

Thanks for the reply. I saw a video of a snapped magnet. The guy said he had never seen anything like it in 16 year. Seems to fit the bill though. I'll have a look later today if I can

Re: Curvy Stator Issues. Bike cuts out
 

Magnets on the rotor are all intact. However when I pulled off the stator cover a small, thimble size, stone dropped out. The coils don't look damaged from what I can see. Stuck again!

Re: Curvy Stator Issues. Bike cuts out
 

Bump

Re: Curvy Stator Issues. Bike cuts out
 

Even with the battery hooked up to my car still having the same symptoms. Surely this rules out the battery as the cause?

Re: Curvy Stator Issues. Bike cuts out
 

It could be coil/s failure and even faulty plug caps can limit the engine.

See this post,

http://forums.sv650.org/showthread.p...hlight=SD05FMB

and I use the Red ones,

but these are the same,

https://www.ebay.co.uk/itm/Suzuki-SV...frcectupt=true

Re: Curvy Stator Issues. Bike cuts out
 

there should be nothing dropping out.. if it did then its been floating about in the engine = bad news.

the only thing that should come out of an engine is oil, everything else should be bolted down.

Re: Curvy Stator Issues. Bike cuts out
 

Not looked in until now. Agreed connecting a second battery should rule out electrical problems, however the main connector on the starter relay that takes power to the loom can go, so unless you have bypassed this then it could still be at fault - mine had partially melted and started making intermittent contact and gave up in the end.

Re: Curvy Stator Issues. Bike cuts out
 

Appreciate the replies guys, all good stuff.

My spark plugs are less than a few months old but I'll get them out and test them anyway.

My starter relay is also new too, so doubt the issue lies there. I'll keep posting when I find out some more

Re: Curvy Stator Issues. Bike cuts out
 

Test the Spark plug caps.Brand new they should read 5k ohms.Anyhing North of 8k ohms and I replace them.

Re: Curvy Stator Issues. Bike cuts out
 

Oh the caps themselves. Hadn't thought of that.

Many thanks.

Would these going, however, make me lose all electrics before cutting out?

Re: Curvy Stator Issues. Bike cuts out
 

I had a faulty plug cap that limited the Bike to around 5,000 revs/60 Mph on an old Honda :O

Re: Curvy Stator Issues. Bike cuts out
 

It's not the relay I'm referring to, but the plug on the wiring that takes off the relay:
https://farm9.staticflickr.com/8775/...c5b307aeb7.jpgIMG_20110427_161807 by Richard Orrick, on Flickr
On mine, the main pin had obviously got hot and the plug started to deform, so while riding it was losing the connection until in the end it gave up. Even when I took it off it didn't look bad, but I knew it was the problem because waggling it changed things, but on closer inspection you could see the plug wasn't right. It's worth a look, my bike is 1999 and had covered over 40k miles by that point.

Re: Curvy Stator Issues. Bike cuts out
 

I will take a closer look. I have noticed before that one of the pins sat slightly deeper than the other like it had moved, but not enough in my opinion to lose contact. I also disregarded this because my problem isn't with starting (initially anyway).

Could you recommend a place to buy a replacement plug?

Re: Curvy Stator Issues. Bike cuts out
 

So I rebuilt today. Put in some new iridium plugs. Battery charged (also did a current leak check before connecting negative terminal to check for shorts, all was good). She started up fine, but I quickly turned off as my NEW rr was heating up and starting to melt. So I am back to thinking my issue lies on the stator side of thing. Either the stator itself, or the wiring upto it. Possible cause of the overheat could be the stator over volting right?

Re: Curvy Stator Issues. Bike cuts out
 

Good diagnostic page here,

https://www.triumphrat.net/speed-tri...r-upgrade.html

Re: Curvy Stator Issues. Bike cuts out
 

very difficult to see how a stator can produce too high a voltage unless it gets more coils of wire, spins faster or has stronger magnets!
Think the overheating R/R can only be down to the something drawing a lot of current on the DC side or the R/R having a poor connection locally and the high resistance is generating the heat.....

Re: Curvy Stator Issues. Bike cuts out
 

Yeah I was thinking more along the lines of back emf with regards to over volting.

Just out of curiosity, after hours of searching about dodgy stator, I can find no mention of inspecting the metal contacts at the end of the winding "rods". People only seem to go by what the windings themselves actually look like. My metal contacts do look extremely worn so I'm wondering if this could be an issue?

Re: Curvy Stator Issues. Bike cuts out
 

cant visualise the winding rods you mention as I thought the stator came in a unit with the three wires already connected so that the whole thing just bolts into place and the connector on the wires plugs into the bike one. Im still going with the connection to the R/R having a high resistance and overheating....

Re: Curvy Stator Issues. Bike cuts out
 

https://i.ebayimg.com/images/g/FXoAA...I9n/s-l225.jpg

Image isn't the same as my stator, but I mean the metal rectangular ends sitting on the green plates.

New regulator (mosfet type this time) is enroute and hopefully shall see and end to this misery

Re: Curvy Stator Issues. Bike cuts out
 

The stator has no contacts, it's like a brushless motor. Provided the wire is coiled around it and its insulation is fine, it'll work. If your RR is a MOSFET one then it shouldn't get as hot as a "normal" one like the stock one, but the stock one will get hot as that's how it dumps the excess current that isn't going into the battery. Can you check the wiring from the RR to the battery to make sure the juice is getting through? As said above, also try disconnecting the RR and running on just the battery, it will work just fine while there is life in the battery. Once you have it running then check you get at least 75V AC from the stator (RR disconnected for this test anyway) using the three wires in pairs i.e. 1 and 2, 2 and 3, 1 and 3.

Re: Curvy Stator Issues. Bike cuts out
 

On the agenda first thing in the morning. I'll make sure my battery is charged enough. Then I'll take voltage readings from each stator wire, and then connect the regulator and take readings from the outputs of that too.

All well and good so long as the bike stays running, which it wasn't before removing the dud connector, and fitting new plugs. Will post an update tomorrow.

Many thanks for the help, really appreciate you going out of your way here.

Re: Curvy Stator Issues. Bike cuts out
 

NP man. Think of the rule of two, how do I divide my problem? And the rule of one, change one thing at a time.

Re: Curvy Stator Issues. Bike cuts out
 

Good afternoon.

So I ran the tests mentioned above earlier on. Stator was outputting 22v at idle and 63+ at 5000rpm. Measured from the connector that plugs into the RR. So that's that ruled out.

Next I connected the RR and measured the DC output. I was only reading 2.1ish volts at all rev ranges. So the RR is definitely gone.

What I have noticed is that I'm practically running on one cylinder also (the new spark plugs are probably stopping the bike from cutting out as it was before) . Now I'm wondering if I had the misfortune of a mechanical and an electrical fault occurring simultaneously...

I plan on rejetting soon and will ensure my air fuel mix is correct, install a mosfet RR and hopefully... This will finally be over :)

Re: Curvy Stator Issues. Bike cuts out
 

It's quite common with electrical problems that one part drags down another over time.When my R/R went it took the battery with it :(

I fitted a Mosfet one and chronicled it just in case

https://cx500.000webhostapp.com/Mosf...sfetUniRR.html

Check the in-line Stator Block connectors.My Curvy had two!

Re: Curvy Stator Issues. Bike cuts out
 

My front cylinder is running very weak and spluttering. Also smells of fuel.

Airbox is on.

When I bought the bike it was popping, and I swapped it out for a dual delkevic full exhaust system. Had my carbs cleaned and balanced since but haven't gone near the jets.

After inspecting the stator and surrounding areas and finding no signs of damage, I can't be sure the stone was actually inside the case or was stuck to the outside of the cover amongst dirt and grit.

Re: Curvy Stator Issues. Bike cuts out
 

To confirm the state of the R/R I would do the testing as recommended in the Suzuki manual. Youll need a multimeter which then can check that the rectifier diodes are all ok however note that even if the results are good unfortunately its still not a 100% guarantee the unit will work correctly....

Re: Curvy Stator Issues. Bike cuts out
 

When you say the carbs were balanced, you mean after they went back on the bike? Because there's no other way to do it. Regarding jetting, it could probably do with some rejetting to match the can but stock will work just fine if a little lean, so if in doubt use that. Check EVERYTHING such as idle screw settings, needle clip settings. The downside of buying an old bike is people have had a lot of time to "improve" it. Also check for a stuck choke plunger as my front one is way worse than the back, though all this really does it richen it up a bit, it doesn't cause real running problems.

Re: Curvy Stator Issues. Bike cuts out
 

Carbs were balanced after they were back on of course. Didn't do them myself, but had it done at a mates garage. Choke cable was also replaced as it was duff, but I shall have a check of it again.

I'll give everything you suggest a go. I'm confident the bike will be purring after I've been through it. I'm even planning to rewire the whole thing just for good measure and a bit of practice :)

Re: Curvy Stator Issues. Bike cuts out
 

Fair dos. The sticking choke is mainly the plungers themselves, mine builds up a bit of crap where the plunger seats so it won't shut off properly.

Re: Curvy Stator Issues. Bike cuts out
 

I have same issue with 2001 curvey, Alternator coils checked out, but battery and the bike die after 20 ish miles.
In the end I had faulty alternator coil, which shorted when hot, the lacquer insulation on the coils had small cracks which opened up to create an electrical short path.

After fitting a new alternator and cover gasket I had a problem with the bike stalling at junctions or traffic lights.
As the fuel tank had been moved to remove and re-route the new alternator harness it is common to trap the fuel tank breathers, which can also cause the bike to stall when idling, as in my case.

Re: Curvy Stator Issues. Bike cuts out
 

Interesting, thanks for sharing. I suspect your alternator was living on borrowed time, once any sort of short circuit starts in the windings they burn out fairly quickly.

Re: Curvy Stator Issues. Bike cuts out
 

Yes, the technical term F***ed.
While at Lucas some fair years ago now, the same used to happen to their alternators, mainly they failed due to the in built rectifier diode packs though.
I believe the hot oil can age the lacquer quickly.

Re: Curvy Stator Issues. Bike cuts out
 

Chris did you ever solve this? Mine have very similar issues