Break In Help?!? New Bike/Motor died. Fouled Spark Plugs. Why/How? Best Plugs to buy?

Discussion in '2-Stroke Engines' started by bigkev81, Dec 11, 2013.

  1. bigkev81

    bigkev81 Member

    Hi guys,

    I've had my bike for around 2 weeks now and have been running/breaking the engine in. So far I have only used it for short trips at night when it is nice and cool, for 1 - 3kms average per night. Because I am still breaking the engine in I have been riding pretty slow, most times only opening the throttle 1/4 way max, trying to keep it under 20km/ph, but sometimes reaching 30km. Then tightening the head bolts when I get home after every ride.
    I reckon I've ridden about 15 - 20kms in this fashion.

    Anyways, today I decided to ride instead of catching a bus to the train station, then taking my bike on the train.The total ride is 5.9kms. Made it most of the way, after 5.2km bike started losing power and was dead within .2km. I pedalled the rest of the way but I could not get the motor started up again, even after letting the engine cool down for half an hour.

    I was feeling really bad, thinking I had broken my bike. Maybe I should have waited till the motor was completely broken in before taking it on a longer ride I was thinking.

    Anyways, at the train station my friend who also has a 66cc motored bike, put his spark plug into my bike and my bike roared to life running even better than before.
    He told me my plugs had fouled up, and thats why it wasn't firing.

    The bike is so new and had such little use. What could be the cause of this? And how can I prevent it? I'd like to know so this doesn't happen again. As I had to do a lot of pedalling today in the Australian summer heat, NOT FUN at all!

    I've ordered 2 more spark plugs via overnight courier so I can keep a spare on my bike at all times just in case. But my mate told me the stock ones/recommended ones aren't very good. The word he used was "cheap ****" lol. What is a good spark plug to get for my bike?

    When he showed me his, his sparkplug had 3 of those prong things at the tip, he told me it sparks 3 times? So even if 1 misses it will still always fire. Anyone know what these are called? I'd like to get some of the same plugs. My friend couldn't tell me what they were called, only where to buy them. But due to my work hours I can't get into the shop during business hours, I need to source them elsewhere by ordering online. Would be nice to know exactly what I was after :)

    Sorry for the long post, just wanted to include as much info as possible so I get the best advice.
    Thanks a lot guys and girls.


  2. grinningremlin

    grinningremlin Active Member

    OK, I'm thinking you've got too rich a mix, OR your carb setting is not lean enough.CG engines are run super sloppy with oil (32:1 ?) which is nuts to me, but in order to keep those sloppy engines running they need it.So you're always on the edge of fouling, and running at slow RPM's (break-in) compound the foul possibility.You can clean and regap (if needed) the plug, and it will work fine.A three pronged sparkplug will still get fouled if you're too rich.
    Always keep super-fine sandpaper in your kit, loosely double a small torn strip of it and run it between the electrode and ground prong and it should work as new.If it's really gunked up, WD-40 on a rag for general wipe-off, and clean out with a toothpick or something, just don't throw it away without trying to restore it, that's $$ in the trash.Good luck.
  3. Leroybrown420

    Leroybrown420 Member

    My guess would be; wrong fuel mixture or defective plug. The stock plug are not the best. Also, make sure the choke is off.

    Good Luck!
  4. Big Red

    Big Red Active Member

    It wont hurt to wind out the engine a little during break in. Just dont hold it WOT more than a few seconds. Running a 2 smoke at low rpm can foul plugs, They weren't made to lug. Rev it up a little to keep the plug burned off.I use the NGKB6HS. It's the most recomended plug for the China Girls. ALSO, When ya order the plug, order a good auto grade plug WIRE & boot, As yer finding out, The chinese crap is CRAP
    Big Red.
    Holly likes this.
  5. LeTweek

    LeTweek New Member

    The word he used was "cheap ****" lol. What is a good spark plug to get for my bike?

    The 3 prong LD Z4JC plugs that came stock with the 66/80 kits for a while, would barely allow the engine to run at all. After exhaustive troubleshooting I narrowed my troubles down to those plugs. The NGK B5HS work fine. I had some problems with carbon build-up in the piston area so I use the NGK Iridium BPR7HIX 5944. So far so good.
  6. Big Red

    Big Red Active Member

    So does the B6HS and trhe B7HS. I just run the one in the middle of it all B5-(B6) -B7. The only difference is a very little difference in the heat range. The B5HS stays a little Hotter than the B6HS. It doesn't have a HOTTER spark, Just holds more heat in the porcelain for easier restart in cold weather. there was a HUGE debate on what plug is better, NO ONE WON that one because it depends where you live what plug is better for YOU. if you live in the artic, go with the NGKB5HS. The desert, go with the B7HS, I live in California, Good riding weather MOST of the time. The best all around plug is The NGKB6HS
  7. bigkev81

    bigkev81 Member

    Hey guys,
    I'm having trouble knowing which plug wire and boot to buy. I went to the local autoparts store, with my current plug wire and boot and asked him for a replacement.
    "He said we don't have anything like that, looks like its for a lawn mower"
    Can you guys recommend a good plug wire and boot to ask for?

    Kev :)
  8. crassius

    crassius Well-Known Member

    you want a solid copper core wire - a lawnmower shop should have it
  9. bigkev81

    bigkev81 Member

    I thought auto grade would be like for a car or motorcycle and be better quality than the lawn mower parts. Or is it the same?
  10. crassius

    crassius Well-Known Member

    all solid copper core should be about the same
  11. bigkev81

    bigkev81 Member

    kay cool. How about the boot? Just find one that fits the NGK spark plugs? Or is it not that simple.