CF Moto V Night Stalling and running rough

[OzChinaRider]

Hi All, I’ve recently got my hands on a vnight and the first few times I took it out it ran just fine. Im now having a problem where it starts up ok and idles fine but once I’ve been out for a few minutes it starts to run rough and stalls.

At first I thought it might be a fuel starvation issue due to poor ventilation. I took it out for a quick spin tonight with the gas cap open and I still had the same problem. What other causes should I be looking at? Once it starts running rough it also starts making popping sounds like back firing at higher revs and also start pinging.

[ben2go]

Dirty carb, valve adjustment, bad spark plug, failing coil, failing CDI, bad air filter, cracked carb intake boot. The list goes on and on.


I would check the valve adjustment. This gets severely neglected and causes the exact issue you describe. I don't know the specs or procedure for your specific bike. If that checks out, I would move onto cleaning the carb and changing the air filter. If that's OK, I would move onto checking the ignition system.

[humanbeing]

As i said b4 it's based http://chinariders.net/showthread.php?t=15544 (Those files no longer in that AU site. Luckily someone re upload to other sites. Google it...) on Suzuki 125
Carb: http://chinariders.net/showthread.php?t=16157 -Mikuni VM22

[OzChinaRider]

So I got home from work today and started it up. It ran like an absolute dog and stalled before too long. No problem, I inspected all the fuel lines and couldn’t find anything off. So I pulled out the spark plug for inspection. It looked ok to me. I did a spark test to make sure it was lighting up and sure enough it did.

Put the spark plug back in and started it up. Again it was running really rough and stalled quite quickly and wouldn’t restart. Took the plug out again and did another spark test - yep all ok. So I put it back in and started it up again - it fired up and ran perfectly. I kept it running while I reassembled the fairings and did a couple of things at home - didn’t miss a beat. I then took it for a short ride - only about 5 minutes because I had to make dinner and then bloody thing never missed a beat.

The only thing I can think of is that perhaps it’s a bad lead or the lead wasn’t attached properly. It kind of worries me that I got it running without finding a definitive answer (I don’t consider this a definitive answer because the lead seemed to be attached fine before and after I looked at it), because I don’t know when it will play up again.

Will post back here if I run into this problem again.

[humanbeing]

the owner's manual & similar 150 service manual can d/l from: http://autoinfo24.ru/rukovodstva-po-...ekhnika/cfmoto

[JerryHawk250]

As Ben2go mentioned check the valves lash. They may need adjusting. Tight or no valve clearance will cause all kinds of running issues.

[OzChinaRider]

Originally Posted by JerryHawk250

As Ben2go mentioned check the valves lash. They may need adjusting. Tight or no valve clearance will cause all kinds of running issues.

It’s only done 1200km - is that likely to need adjusting at such low mileage?

[JerryHawk250]

Originally Posted by OzChinaRider

It’s only done 1200km - is that likely to need adjusting at such low mileage?

Yes.

[humanbeing]

157MJ-2A (145cc)

157MJ-3 (149cc)

[OzChinaRider]

It happened again. But I’m noticing a pattern. First time it happened I was leaving the car park at work down a steep descent. When I took it for a test ride earlier in the week it was fine until I went down a steep hill and it stalled at the bottom. Yesterday it happened at a set of lights at the bottom of a valley. After I finally got it started, just past the bottom of the valley it ran fine.

So I have a big weekend coming. Firstly to check the float bowl in the carb, but I will also check the valve lash. Wish me luck fellow China Riders.

[humanbeing]

Pls also checks the electrics. These Suzuki (& copycats) igniter relies on healthy DC 12V ±3V

[RedCrowRides]

Hey man ,if it has the factory fuel lines I'd replace them ASAP ,the Chinese ones start to
flake from the inside and it sounds like you might have trash being sucked into the jets
when on or coming off an incline ,I'd look at that as well as making sure the carb is clean and float isnt sticking ( also valve lash) , if you see black specks in bottom of carb float bowl, it's dem no good fuel lines goin bad.

[OzChinaRider]

Originally Posted by RedCrowRides

Hey man ,if it has the factory fuel lines I'd replace them ASAP ,the Chinese ones start to

flake from the inside and it sounds like you might have trash being sucked into the jets

when on or coming off an incline ,I'd look at that as well as making sure the carb is clean and float isnt sticking ( also valve lash) , if you see black specks in bottom of carb float bowl, it's dem no good fuel lines goin bad.

Fuel lines are all new. It was one of the first things I did when I bought the bike because the original lines didn’t even reach to the carb. I don’t know what the previous owner did to it. I’ve decided to order an new carb instead of messing with the old one. The good thing about these bikes is the parts are inexpensive. This weekend I’ll be replacing the carb and air filter and checking the valves.

[ben2go]

Originally Posted by OzChinaRider

It happened again. But I’m noticing a pattern. First time it happened I was leaving the car park at work down a steep descent. When I took it for a test ride earlier in the week it was fine until I went down a steep hill and it stalled at the bottom. Yesterday it happened at a set of lights at the bottom of a valley. After I finally got it started, just past the bottom of the valley it ran fine.

So I have a big weekend coming. Firstly to check the float bowl in the carb, but I will also check the valve lash. Wish me luck fellow China Riders.

If hills cause it to shut down, the carb float level may be to low.