Bike spluttering/backfiring? NOW WITH MORE VIDS

[mjc85]

Hey all my new bike doesn't rev consistenly all the time, sometimes it just splutters. I have adjusted the small circlip on the carby slide and tried all positions and found 2nd from the top to be the best. But this has not solved the problem, it feels like the bike doesn't rev as far as it should and it cuts out and in the mid range it cuts out and you gotta back off for a second then it comes good.

So i've tried the circlip what is the next thing to try? What else could be causing this

 

[RabidDog12345]

maybe the carb is full of shit.. pull it apart and clean it out,,, maby try a new fuel filter.

 

[mjc85]

Will do that tomorrow.

 

[mjc85]

I think i fixed it, the plug that goes into the C.D.I unit has 5 female connectors in there, one of the females was not pushed right in, so i think when connected to the male on the C.D.I it wasn't getting full contact. Do you think that could've been the problem?

I'm about to go out to the bush and test it out properly.

 

[mjc85]

It's still doing it, i don't think its fuel because i have tried every setting on the needle in the carby. I think its gotta be something in the electrics.

Can the C.D.I units be faulty ? I have checked all connections they seem to be ok.

On the coil on the left side i see there is some wires in behind there, to take the coil off do you need a torque wrench when you do it back up ?

 

[HIROSHIMA SCREAMER]

Mate...check your spark plug. Even if you get a spark when u test it up against the head, it doesn't necessarily mean your spark plug is working properly, remember, your plug will make a spark a lot easier out in the open it's another story under pressure in the cylinder. I had the same problem you described and a new plug sorted it out.

 

[Cruzen]

i had the same problem, changed the spark plug, worked like a charm next ride. seriously.

 

[mjc85]

The standard plug was "Torch" brand, i have changed it with a NGK CR7HSA and it still has the same problem?

 

[RD RACING]

you must eliminate one thing at a time or you won,t know where your at, you know your new sparkplug is good now you must go through the carby clean out and also the fuel tank internal , [ remove and flush out ] if you still have problems after this clean out you may have an electric problem.

 

[mjc85]

you must eliminate one thing at a time or you won,t know where your at, you know your new sparkplug is good now you must go through the carby clean out and also the fuel tank internal , [ remove and flush out ] if you still have problems after this clean out you may have an electric problem.

RDRacing, i dont think its a carb problem to be honest :?

Because the plug is pretty black so it makes me think it is already getting enough fuel or too much, it is set on the 2nd leanest circlip setting right now which seems to be the best.

I will try cleaning out the carby anyway and see what happens

Would the best way to clean the carby out be just to open it up and goto the service station and use they're air compressor to blow through most of the holes and the main jet ?

 

[mjc85]

Here are some videos of the bike running, the one where i am riding that is flat out in 2nd gear. It does this with the Needle circlip on all settings.

I have checked wires, changed spark plugs, cleaned out carby, checked fuel lines/tap and cleaned out the tank, changed the oil and tried with fuel cap off and breather off fuel cap lid, with air filter off, ive tried just about everything.

http://media.putfile.com/Orion-Running-Bad Bike full acceleration in neutral

http://media.putfile.com/Orion-Running-Bad2 Bike fuell acceleration in 2nd

The only other thing i can think of before going and starting to replace electrics or pull down motor is the oil.

Only 530ml of oil came out when i drained the chinese stuff, and i put 730ml back in, so could i have to much oil in there ?

Also when i first rode the bike for a little bit i forgot to take the zip tie off the crank breather, but i only rode like this for maybe 2-3 mins.

The carby on my bike is a Mikuni 25mm with a slide choke so removing the choke isn't going to do as much as removing it from a carb with a butterfly choke.

 

[mjc85]

Could the coil be faulty not giving it a big enough spark ?

Could i use a Kitaco Super ignition coil with a standard CDI or visa versa(standard coil with a kitaco or TBtrail high rev CDI) ?

 

[No-Fear]

how about insted of wasting money on a part u THINK might fix it, take it to a mechanic and get him to check it out and give u expert advice on what is the REAL problem, then u know wat u have 2 buy with out guessing. just my thoughts.

 

[mjc85]

how about insted of wasting money on a part u THINK might fix it, take it to a mechanic and get him to check it out and give u expert advice on what is the REAL problem, then u know wat u have 2 buy with out guessing. just my thoughts.

It's cheaper to buy these parts than take it to a mechanic, thats why and the closest mechanic that will work on pit bikes is 30 minutes drive away.

 

[mjc85]

How do you set float level and what is the correct float level for a mikuni 25mm with a size 56 jet ?

Mitch

 

[mjc85]

Problem fixed, the carby was f ked. It runs 1000x better with a new one, just gotta wait for a new one from the seller i bought from

I finally gave up and took it to the guys at

Pocket Bike Dominion
11 Daniel St Caloundra 4551 (07) 5492 6566

Real helpful guys, if you are on the Sunshine coast and need spares or have a problem go see these guys, don't get ripped off on your spares through ebay. They won't charge you an arm and a leg for parts or labour.

Mitch

 

[No-Fear]

told u to take it 2 a mechanic from the start. no point playing around with chinese gear unless u know what u are doing. good 2 hear u got it going.

 

[Dirt Bikez & Pocket B]

yeh u would have saved time and depression (lol) if u took it 2 a mechanic :lol:

 

[mjc85]

told u to take it 2 a mechanic from the start. no point playing around with chinese gear unless u know what u are doing. good 2 hear u got it going.

Mate i have a very fair idea of what i'm doing, all the bike shop did was do everything i had already done until they figured it was the carby, i had an idea it was that but i wasn't gonna go buy a new carby and them find out it's something else. But yeh i'm glad its going good now. They got some nice bikes arriving there in about 4 weeks that are gonna put thumpstar, motovert and what ever other brands to shame and only gonna be about $1800.

 

[No-Fear]

They got some nice bikes arriving there in about 4 weeks that are gonna put thumpstar, motovert and what ever other brands to shame and only gonna be about $1800.

yeah mate, we'll see, not many bikes come close to the quality of thumpstar & provert here in AUS. When a bike cost $1800 and a 06 thump is $3500, u know there is going to be some quality issues with a cheaper bike.
Lets see how the import test bikes go in free rider mag, they doin tests on quite a few import bikes.