Mini Dirtbike 50cc 2 stroke, cut's out after a few minutes

Mini Dirt Bikes & Pit Bikes Forum

Help Support Mini Dirt Bikes & Pit Bikes Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

paulphonak

New Member
Joined
Mar 26, 2014
Messages
2
Reaction score
0
My son's mini motorbike is a 49cc one.

After riding for a few minutes, it starts to cough a bit and then cuts off. After a few minutes, it starts again and then cuts off a few minutes. We had never managed to ride it until the fuel run out. I fitted a new air filter which did not make much difference. I replaced the spark plug which again did not make much difference. We did spray water on the

I purchased the bike from someone last summer who said he replaced the followings:

Exhaust Gasket
Carburettor
Fuel Pipe
Fuel Filter
Inner Tube
HT Lead and Body
Rear Brake Calliper
Rear Brake Pads
Kill Switch Mounted onto Handlebars
Full Body kit Including seat
Pull start

I am no expert on mini motorbike but I am struggling to eliminate possible causes.

Can anyone help?

Paul
 
are there any kinks in the fuel line ?

are there vacuum leaks ? to check, spray some wd40 around the carb, and if the idle changes at all, you've got a vacuum leak.

its one of those 2 stroke 49cc bikes right ?
 
Thanks for your reply.

I don't believe there is any link in the fuel line otherwise we would have noticed the fuel hanging around.

It is a 2-stroke 49cc bike. I shall spray the carb with WD40 and see what happens.
 
Can you put some pics up mate so we can see exactly what the bike is?

Sounds like clogged jet's to me. Is it at any particular throttle position or does it just die off idle after a few minutes?

Oh and Welcome to Miniriders. :)
 
hey, welcome to Minirders,

this thread will help you work out how to upload some pics etc-
http://www.miniriders.com/general-c...ers-old-new-few-helpful-tips-hints-ideas.html

and also drop in here and introduce yourself too-
http://www.miniriders.com/general-chat/20824-introduce-yourself.html


so is this basically what your carby looks like, the one with the plastic fuel tap on the side ?




another thing, what does your Spark Plug look like when you take it out ?
and is it a Genuine NGK Spark Plug, if not grab another one from Bunnings for $4 etc,
they are a lot more reliable than the china plugs that come standard with them.


cheers, craig
 
fuel bowl not filling up quick enough to keep up with flow maybe? then filling back up when left sitting for couple of mins? just a thought.
 
paul hasn't been back on since his last post.
think the fuel tap might have some plastic or dirt in it ?

or he has the fuel/oil ratio wrong maybe ?
 
yeah possibly, i just remember the young boys first bike, which was one of those 300 dollar 2 strokes, did a similar thing and it was the float level on it. hope he sorts it out, sucks when the kids cant ride for as long as they want.
 
Thanks for your reply.

I don't believe there is any link in the fuel line otherwise we would have noticed the fuel hanging around.

It is a 2-stroke 49cc bike. I shall spray the carb with WD40 and see what happens.
What happend need to know having the same problem
 
fuel bowl not filling up quick enough to keep up with flow maybe? then filling back up when left sitting for couple of mins? just a thought.
Hi mate, I've read what u said about fuel bowl not filling quickly enough, I believe I have the same issue. How would I fix this ?
 
My 110cc pit bike did the same. Until I read about these small carburetors having a tab on the bowl, this tab prevents the float from going down and opening the valve, i shaved that tab in the bowl. And problem solved.
 
My 110cc pit bike did the same. Until I read about these small carburetors having a tab on the bowl, this tab prevents the float from going down and opening the valve, i shaved that tab in the bowl. And problem solved.
Shaved the tab ?
 
My 50cc keeps cutting off as soon as my son pulls off and gets maybe 10 20ft need help
 

Latest posts

Back
Top