I just got a new 125cc pit bike, and it seems to be gutless. Tell me if i'm wrong but you should have no problems getting the front wheel up in first without having to sit all the way on the back and yang back as hard as you can?? Theres alot of poping and it's hard to keep idling with the choke all the way off, even after its warmed up. I knew i was getting a cheap bike, but it's still a 125, and i've herd decent things about them. It is a junker or does it just need to be tuned by someone who knows what they are doing? it's fresh out of the box, and i was hoping to put in some oil and gas and getty up. We messed around with the carb and the spacing on the rods. like .051 or something. this didnt' seem to help. Not sure if it's not engaging into gear all the way, or its not getting enough gas or spark.. It gets up and goes, but then you gas it and the engine speeds up and gets noisier, but doesn't really pull at all. HELP !! the front for also bottoms out really easy, should i cut that skid plate down, or switch to 12/10 wheels??

heres what i purchased.

http://cgi.ebay.com/ebaymotors/ws/eB...RK%3AMEWA%3AIT

 

so you are in first gear
get rolling
go wfo
and its just revs?

I would start with adjusting the clutch...




as far as it bottoming out,tighten suspension as much as possible,or convert to better shocks

 

find out whatbrand motor it is (jialing, lifan..etc..) and then get a high compressionn piston kit for it, maybe a better cam and if youcan port the head... theya are really restrictive in the ports frm the factory, and they have low compression ratios ...that's almost all chinese motors

post up some close up pics of the motor and maybe i can help you find out what kind it is

 

Take the motor out and put in an sdg 107.

 

yeah i had same prob with a 125 i bought off e-bay cheap,the engine was new but it was junk,as the previous guy said,get it tuned.

 

Well the whole point of getting this bike was to keep it really cheap obviously. Thanks for the input, I'll get some pictures up of it. I think it's a lifan or a longcin.

Are these actually 125cc's ? I don't know much about bikes, but how can it be SOOOO different from like a CRF125 2 stroke? I didn't think that there was that much power difference between 2 and 4 strokes, just power bands and power delivery. Info ?

 

To bad you dont have a clue of what you are talking about.
The motor in it now is a 125cc Lifan (more power than the sdg)

Anyhow.
You fvcked yourself buying that bike. The only thing good on that is the motor. Soon the hubs are going to crack and the forks are going to give and so on and so on.

I know money is tight but those things are junk. I had a guy here in Chicago selling them on my website. They all fell apart but before that I rode one and could wheelie it with ease. (but I have been doing wheelies on 50's for over 4 years) New street tires will help.

Just need to ride and try alot. It's got a clutch...USE IT.

Good luck and have fun (while it lasts)

PS, Tighten all the spokes and every bolt on the bike before it falls apart.
Don't say I didn't tell you to tighten everything...do it now

 

haha.. true-er words have never been spoken.. but we learned the hard way. I was riding it and the whole exhaust fell off the bike and on the ground, it was pretty fukin hilarious...and then 2 of 4 bolts fell off the rear sproket.

so.... what kind of money do you think needs to be spent to have a good frame and good engine with decent suspension, so we can beat the **** out of them and not fix them every day... ? should we sell them and save for ...??

 

It's hard for me to give you advice on that without you taking it the wrong way. I've been riding 50's for a LONG time (4 years, look at my profile for the last couple of posts i posted in and ull find a thread called 1st fiddy,,got to be 10 or less posts)

but that thing just flat out sucks, try and pawn it off to someone.
or just keep wreching. it's not the frame you so much have to worry about or the swinger so much...

what you can do with the forks is put 20w fork oil in.

 

So are Lifan motors still good motors ,just the rest of the bike is junk?

what do you think about building a bike around the Lifan 150cc like this one:

http://cgi.ebay.com/ebaymotors/ws/eB...MEWA%3AIT&rd=1

One just sold on Ebay for $202 , with $84 shipping.

 

That only fits in a crf 80/150/230 frame and up.
That motor will not fit in a 50 frame.

Anyhow, your motor is not the problem.
Let me know if you have anymore Q's