RX3 Starter Issue
 

Here's the deal: the bike I bought had a problem with the starter, which is why the previous owner took it to a mechanic to get it fixed. I saw the mechanic totally disassemble the starter clutch assembly, replace the starter clutch, and put it back together. I was told the piece called the Bendix was okay for now, and should be replaced in 35-40,000km.

The bike had a little trouble starting the last couple days, but was able to start in about a minute. Today, when trying the start the bike (fuel line on, kill switch not engaged, full choke), it just wouldn't turn over. I could hear the starter whirring but not engaging. I checked the battery voltage and it's at 12.40. After trying to start the bike for about 30 min (not continuously, trying a few times then taking a break), the engine finally started when I was testing the battery.

Was this just a coincidence? Should I go back to the mechanic since the starter problem isn't fixed? I don't want to have a problem starting the bike on a daily basis.

What other diagnostics can I do with basic tools and a multimeter?

Thank you!

If the battery is good, I'd tear into it. They're not too complicated, this is a good video to watch: https://youtu.be/CrYbQ6OkU0Y it's not specifically for an RX3, but the starter motors on almost all motorcycles are basically the same.

The (in)famous starter overriding clutch issue that seems to plague the bikes sold in South America. CSC/USA ones didn't reported as high an incidence of this as ours. If the part the mechanic replaced was only the collar with the pieces held by a spring, and he did NOT replaced or at least polished the holding gear/bush, it's not rare that it failed again fairly soon. No diagnostic can be made from the outside without opening again the right crankcase cover. But is the symptoms you describe are those... whirring noise when pushing the starter button but the engine not turning over, then there's almost no doubt that it's the same problem than before. Low battery symptom is different; clicking or rapid tapping noise from under the seat, where the starter solenoid is located.

I don't really have much of a choice but to start ripping it apart... but, I did check the battery again, and now it's sitting just under 11. Could it really drain that quickly? Testing the battery while pushing the starter button, it's at about 5-6.

Also, just tried starting it again and the bike was really close to turning over, but made a clicking sound then shut off. Should I just go ahead and get a new battery?

I guess I'm the idiot for buying a bike and not thoroughly researching it beforehand, and just finding out now this is an infamous issue. Juanro, you described what happened exactly, the spring collar was replaced, but the holding gear/bush was not. So does this mean the entire starter assembly needs to be replaced to fix this problem? Would I really be able to do anything if I take off the right crankcase cover, without more replacement pieces? Or would it be helpful to still inspect/clean the parts?

How can I check the starter solenoid?

Thanks for the help.

Just checked this (starter relay?) and it's at 10.6

It sounds like the battery has a dead cell. The easiest way to test the battery would be to try starting the bike, while you have a voltmeter on the battery, and see what the battery voltage drops to when you try to start it. Anything under 11 could cause it to not start, it just depends on the ignition. Anything under 10 almost definitely wouldn't start. I would try all of this with a new battery. Just to check, all grounds are tight?

You can test the function of the starter solenoid by taking a big screwdriver and shorting out (connecting the two terminals covered by rubber in the bottom photo) both sides of the solenoid. If it were me, I'd bump start the bike so that it can charge, and then re-check everything, as it will all be easier to test with a charged battery.

Those battery values are rather low. And the clicking noise also point in that direction. No need to check the starter solenoid. First charge (or change) the battery. Or you can try with some jumper cables from another bike, or better from a car.

Just got a recharge for the battery, but same issue when pushing the ignition button: whirring noise, won't start. I think this narrows it down to being a problem with the starter. Has anyone else had this issue? Were you able to resolve it by taking off the right crankcase cover and inspecting/cleaning the pieces, or did you need replacement parts?

I second what others have said about your battery, the voltages are too low. Fully charged is 12.7 volts, 12.4 volts is battery sulfation territory. You need to fully charge to 12.7 volts, then let it sit over night out of the bike and check the voltage again. If it is still 12.7 volts, you're good to put it back in the bike and try and start it. If the voltage is below 12.7 volts after it sits over night, you have a bad battery. How bad will depend upon how low the voltage is, but it will still be bad, in which case it will be time to replace it with a new one.

Another thing to check is voltage at the starter relay, with a known good battery (12.7 volts minimum) installed. It should be close to battery voltage, if it isn't, check you primary battery leads and terminals for corrosion and high resistance.

If the override clutch is sliping, no cleaning will solve it.

Sounds like the starter clutch needs replacing if the starter is turning and no engaging. Check on CSC's website. I think there are two different styles for the RX3.

Let the battery sit out after being fully charged yesterday evening and it's sitting at 12.41. Damn, hope I can find a new battery here. Once I track down a new battery, if the bike still doesn't run, does anyone know the availability of ordering starter clutch parts to Argentina? :/

Are you in Argentina right now? There are many levels of qualities and parts to replace, depending on your Budget and how badly (if any) damaged is the sliding Surface of the plate gear Assy (part #16: https://store.cscmotorcycles.com/PLA...-p/z19-115.htm). In Buenos Aires en nearby cities there are also a few mechanics who know this bike well. If you use Facebook you can join our group (https://www.facebook.com/groups/touring250/) and take a look around or ask there.

Hi Juanro, yes I'm currently in Cafayete. Unsure if I should try to hitch a ride with the bike back to Salta, or stay here and have a mechanic look at it. I doubt they will have parts in stock, so it might be a waste to take the bike apart here.

Got a new battery and installed it on the bike, but still no luck. The voltage of the new Bosch one was only 12.15 anyways.

I really just want a bike that runs.

Just requested to join the FB group, thanks for the invite.

The new battery probably needs to be charged, low voltage after sitting is normal, low voltage after charging all night is indicative of a problem. You did the right thing replacing it. Try bump starting it, it's possible that the ring gear on the motor is missing teeth, which could cause it to not be able to turn the engine over, when you stop it after starting it, the ring gear will probably be at a different place.

Thanks for the reply franque, wish I had seen it before returning the battery! Yeah I thought it might not be fully charged after sitting. Ok, I'll get the new battery and try bump starting the bike. That's an interesting point about the ring gear, I wouldn't have thought of that.

PM me and I'll put you in touch with some guys in Salta that may be can help you out.

Worst case I can get parts for your bike in China and send........
DHL etc wont be cheap tho....
Just saying just incase etc

Hey all,

I got some more info if anyone wants to guess what the hell is going on with this bike. I found a moto mechanic in town, and he checked the spark plug, the valves, took out the carburetor, cleaned and inspected it, checked the fuel filter, checked out the air intake box and discovered it wasn't getting any air to the carburetor, so adjusted it. Got the bike to run! I went on a test ride, but the bike wouldn't start again after stalling it. Mechanic checked the high coil (on right side of bike near spark plug, called the "El cable de la bobina"), made sure it was connected, then went on another test ride. Mechanic went on test ride as well.
He checked the idle one more time, and called it good. I rode the bike home. This morning, I was hopeful the bike would run... nothing. Same noise, engine whirring but not engaging. I checked the spark plug again, it's still good.

Any thoughts as to what could be going on??

Ring gear !.... they use a centrifugal clutch..
totally different to a car...



..

I'm talking about the gear on the clutch basket/flywheel that the starter engages (in this case, since I've never had one of these motors in front of me, I'm speaking generally). It could be that gear, if there's an intermediate gear, it could be that, or it could be the teeth on the starter itself, it's possible that one of those gears is missing teeth. Calling it a ring gear is an appropriate, if imperfect analogue.

I had an NZ customer with the pin mount point for one of those gears broken
He needed a new engine case and transmission as well.
There are 2 versions of them gears etc and I suspect 1 caused issues hence the update

More common is sprang clutch and drive gear tho
I can only supply from china..,

Well, looks like the solution is much simpler than expected. Apparently there was a short with the starter relay and the contact drum, as well as the carburetor was set in too much of a fuel saving mode, not supplying enough fuel to get the engine to start initially. Fortunately now I know how to check/adjust this, just moving the small circlip(?) on the center jet of the carburetor (if that makes any sense).

I am relieved it isn't an electrical or starter gear/clutch issue, but I still don't have much confidence in this particular bike since it hasn't started right off the bat the last 3 days.

How many spare fuses/what type do you carry around?

So far my go-to steps for trouble shooting are checking the spark plug and quality of spark, the battery voltage, and that the fuel line & carburetor are getting fuel. Anything else to check/steps to follow if those are all good?

Thanks for all the recommendations! As frustrating as this can be, already learning alot about this particular model of bike.