Pit Bike Help!!

[letsride24-7]

OK, so my buddy just picked up this pit bike from a friend. And has no idea what kind it is or size of the motor.. I can get both the vin and the serial # on the motor if that will help. I don't think it is one of those little Chinese bikes.. It has a four speed with a clutch, 200lbs forks and shock. Looks like a newer crf50 plastics. And so does the motor. But both cases are after market, chromed out that is. Supposedly the guy said it is an xr-crf50 motor with a bigger cylinder, the side of the cylinder is stamped 72ml... This little sucka even as two piston brake calipers front and rear.. It also has one bad a$$ aluminum frame. This thing rips!!

So i ask the almighty dirt bike gods of this forum, to steer me in the right direction..

Thank You!!

 

[letsride24-7]

Bump

 

[Patman]

Got a few pics? Right now it all sounds like a lot of speculation about it's origin and since most minis from China don't have an MSO it would be difficult to tell who made it. Shouldn't the "friend" should have an idea of it's origin if he got it new? If the engine has a manufacturer tag it may help track the origin of the engine which is not going to be the same as the rest of the bike but could be useful for parts sourcing.

 

[Patman]

Does it look sort of like this?

 

[letsride24-7]

The plastics are the same, but the exhaust is straight just like the xr-crf50's. It does have the single swingarm like that. No USD forks and both disc brakes are on the right side. With dual piston calipers. I'm mostly sure that the cases are after market. B/c the high quality chrome plating on them. The frame is also mostly like that, just the one that goes under the tank is tubular and not flat like the side piece. I know that the original owner has like 10 of these little suckers. Mostly all honda's, but he buys all kinds of parts, frames and other things for them. The only thing is he moved away and the last guy do sell it doesn't have his number right now.. Is there some where i can look to match up the motor cases or dimensions to figure it out? And what is the 72ml on the cylinder. Oil level or displacement? I would say i have seen a good amount of bikes from china, and i'm not sure that this is one. It is really solid with one heck of a motor on it. Thanks for looking.

 

[Patman]

Uhhhh. :whoa:

I would venture a guess it is a 72cc engine. If the marking is on the base of the cylinder then it is for certian the displacement. Also consider that 72ml of oil is a pretty tiny amount of lubricant. That being the case I would also venture a very educated guess that it is indeed a China sourced engine. I have seen engines from numerous manufacturers that all offer a variation on the same horizontal single theme. This engine design powers a large part of Asia and there are many levels of quality or lack there of from any number of manufacturers as well as displacements from 49cc up thru +140cc. Very good quality chrome finish is really not hard to get any more as are anodized pieces or even VERY well done engine assemblies, suspension pieces, etc... What was available 2 years ago is VASTLY different than what is available today.

The plastics are bolt on for any CRF type mini including Honda and the fact is much of what people buy is actually from the same source in China no matter what "brand name" they think they are buying.

 

[earl pittz]

One bummer about having a bike like that is you can't find raplacement parts. :(

 

[Patman]

One bummer about having a bike like that is you can't find raplacement parts. :(

If your bike is a Pit Viper that is totally not true! Every nut and bolt is available :cool: