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HELP!! Having trouble keeping RCM 125SX running.

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CRF#319

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Discussion starter · #1 ·
Assembly and break-in went well but now she's having a hard time staying running. It takes 15-20 kicks to start, sometimes more, it then will run for 30 seconds or so then it sputters off at idle(idle screw is set a little high from break-in).

Tried playing with the air/fuel screw, before I touched it, it was at 1 1/4 turns out.

Replaced the plug with a NGK CR6HSA as per reccomendation sheet from distributor.



I'm puzzled, any suggestions?



Cheers, #319
 
#2 ·
Your main jet is too big it comes with a 96 main give me a call I have the 90 and 92 main jets for you at no extra cost.



Like I said in another thread in some places it runs perfect and in others it needs little jetting mods.



You may also have a small piece of dirt in your main. That’s why your bike is hard to start. When you go in to change your jet size take a look at it.



And the dark spark plug means you are running too rich.
 
#5 ·
It sounds to me like it is more than a jetting issue. You are not getting fuel in the carb, your needle and seat may be plugged but it sounds more like a pinched fuel line. Pull the fuel line off and turn on the fuel and watch it flow into a gas can, make sure that it is a steady stream and not a drip or slow stream and that it flows for a while. If it passes that test, unscrew the drain for the carb bowl and see if fuel flows from there freely, if it doesn't than something is stuck in your carb.

I am quite confident that a jetting issue would not cause your bike to shut off at idle after 30 seconds and changing your main jet certainly would not affect it or how it starts so I am not sure why somebody is suggesting that.
 
#6 ·
Well a clogged jet will stall a bike and yes it will affect how it starts.



But I think you have a point because it stalls after 30 seconds so it could be a clogged needle and seat it might just have some little piece of dirt in it clean it out and she should be ready to go. And a pinched off fuel hose sounds possible but why would it happen when at first it ran fine then it didn’t.?
 
Discussion starter · #8 ·
dpw said:
Pull the fuel line off and turn on the fuel and watch it flow into a gas can, make sure that it is a steady stream and not a drip or slow stream and that it flows for a while. If it passes that test, unscrew the drain for the carb bowl and see if fuel flows from there freely, if it doesn't than something is stuck in your carb.
Click to expand...
O.K. I just pulled my carb apart, everything is clean.

The float bowl was full of fuel, so fuel is getting in there.

I checked the fuel line off the petcock and it's flowing well.
 
#9 ·
CRF#319 said:
O.K. I just pulled my carb apart, everything is clean.

The float bowl was full of fuel, so fuel is getting in there.

I checked the fuel line off the petcock and it's flowing well.
Click to expand...
The question is how fast is it getting in there, take the screw out of the bottom of the bowl and see if it flows out steadily. You could also have a piece of dirt floating around in there, blow it all out and see if it still acts funny.
 
#10 ·
Yamadirt 426 said:
K now i have no spark to my rc. I've washed the bike recently. It ran the next day ,then it wouldn't stay running .Then nothing. I've checked all the wiring connections. changed the plug and boot. I'm about ready to kill!
Click to expand...


It is possible that water got into the CDI box. Does it start up and then just run poorly and die when you give it throttle????
 
#11 ·
CRF#319 said:
It takes 15-20 kicks to start, sometimes more, it then will run for 30 seconds or so then it sputters off at idle(idle screw is set a little high from break-in).

Tried playing with the air/fuel screw, before I touched it, it was at 1 1/4 turns out.

Replaced the plug with a NGK CR6HSA as per reccomendation sheet from distributor
Click to expand...


Last year we had some import bikes we were selling from a company (who's name I will not mention, nor do we offer their bikes any more) that had similar problems. It was usually 1 of 3 things. Carb, CDI or Coil. I would have the customer pull the carb and give it a good cleaning. 80% of the time this would do it. Because the bikes are ran at the factory and then they drain the fuel out of the gas tank, but, not all factories drain the fuel out of the carb and the fuel left in the carb can gel up from sitting in there, while it made it's trip to the end user (you) and this would often clog jets or make the float stick. If cleaning the carb did not work, the next thing we would have them check is the CDI. Some CDIs can become defective on the ride over with all the moisture and climate change the experience. Not all of them are sealed well. But, even with a bad CDI box the bike would still usually start it would just run poorly and would back fire or kill when being rev ed. The last would be the Coil. Not very often this is the problem,but, it is something we found wrong with a few of the models we were selling.



Hope this helps you out. It sucks to get a new bike and not be able to ride it. But, I'm sure RCM will take care of you. Good Luck!!!
 
#12 ·
319 it sounds like to me that you may have a carburetor issue some times they are just bad from the factory because of gas sitting in them. Just give me your address and I will shoot a new one out to yah. Anything you need we got it for yah. Hey since you are in Canada I assuming you purchased it from NBX have you tried to contact them to get assistance? I want to see how they handle these issues.



Yamadirt you could of shorted out your stator. I always remove the left side cover after washing and dry it out by blowing air in around the stator then I hit it with WD40 or any similar lubricant this will keep it from building up any oxidation Then after all the clean up I always hit the bike with a gang load of silicone spray all around the wires and motor to keep the moister away.



Oh and normally when a CDI goes it goes there is no in between it just stops working. So if it just started to sputter its very possible you have had some oxidation build up in your stator or your CDI just went out either way give me an email or a call we will get you fixed up and back on the dirt.



If a carburetor or some wiring issue comes up we have you covered.



At least you do not have to replace the shock the frame the pipe the forks weld up a new swing arm or replace it all together and replace foot pegs and peg holder ect.. To get it perform like other bikes.



(951)674-5123
 
#13 ·
SkinDonor said:
At least you do not have to replace the shock the frame the pipe the forks weld up a new swing arm or replace it all together and replace foot pegs and peg holder ect.. To get it perform like other bikes.



(951)674-5123
Click to expand...






It'll sort out, check all the electrical connections, my China bike had a loose key switch and had the same symptoms.



I've seen another China bike have a pinched fuel hose, acted the same way as yours.



In your weather who knows how the jetting is affected also, sounds cold, foggy and moist. Best of luck, it's sure to be a blast once the weather clears up in 4 months:)
 
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Discussion starter · #14 ·
SkinDonor said:
319 it sounds like to me that you may have a carburetor issue some times they are just bad from the factory because of gas sitting in them. Just give me your address and I will shoot a new one out to yah. Anything you need we got it for yah. Hey since you are in Canada I assuming you purchased it from NBX have you tried to contact them to get assistance? I want to see how they handle these issues.
Click to expand...
As I mentioned in a post above, the carb appeared to be clean.

I drained the fuel from the float bowl, pulled out the jets and checked them for blockage, let it sit for 1/2 hour to evaporate the fuel, put it all back together.

I wheeled the bike out on my balcony(I live in an apartment) and it started up first kick and idled on its own, no sputtering off and dieing. I did this a half dozen times, started first kick every time.

I will take it out for a rip tomorrow and see how it runs when hot.



I did purchase the bike from NBX, when I called them this afternoon(3 hour time difference, it was 1/2 hour before they closed) the tech guy had left for the day, he's going to call me tomorrow.

BTW, the bike showed up without a shifter, I called NBX when I realized this and they are FedExing one out to me.



As for parts, I would like to get some jets, 1 larger and 1 smaller pilot and 2 larger and 1 smaller mains if possible.



Cheers, #319
 
#15 ·
319 I sent you a pm last night with some suggestions, it sounds like it may have worked. I'll get Eddie to give you a ring in a bit (when you wake up). We have spare parts here...your bike is the first to have no shifter, but it has already been sent out.



Vince - where are the rest of our spare parts that we ordered? Do we have to come on a public forum to get attention...we need some stators!
 
#16 ·
I highley recommend sending this guy a new stator FYI Vince there is a in between when the stator or cdi is going out or defective ( this is from our own experience). We have had bikes that did exactly what his bike is doing and then eventually it wont start at all. After kicking it 10-15 times and it does start one turn of the throttle it sounds good the next turn of the throttle it cuts out and back fires, then it will die or it will start then die and yes this was on 3 different bikes that we had just broke in. The stators were either wound bad or had moisture in them.
 
#18 ·
NBXAS said:
Stators are the one thing we do not have in stock, we've been waiting patiently up here for back up...Vince any update?
Click to expand...




Guys it seems he got it running again.





[/QUOTE]I drained the fuel from the float bowl, pulled out the jets and checked them for blockage, let it sit for 1/2 hour to evaporate the fuel, put it all back together.

I wheeled the bike out on my balcony(I live in an apartment) and it started up first kick and idled on its own, no sputtering off and dieing. I did this a half dozen times, started first kick every time.

I will take it out for a rip tomorrow and see how it runs when hot.[/QUOTE]
 
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Discussion starter · #19 ·
RB Racing said:
Guys it seems he got it running again.
Click to expand...
I'm not 100% percent sure yet if the problem is solved.

I hope to take it out later today and give it a good run to see how she is when hot.

I will keep you posted.



Cheers, #319
 
#20 ·
As I mentioned before you probably had either a dirty or a bad carb it sounds like you took my advice and went and cleaned it again I'm glad you got it going hope once it clears up you can get some time on the dirt but for now get your butt out there and rip it up in the snow LOL

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SkinDonor
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