X-pro 125cc Engine

[Aimon Jardine]

Sincewe are talking chains here; rollers, sprockets, etc; I thought It fitting to mention what I believe would be a fantastic chain replacement option for any Pit Bike that uses a 420 chain. There is a 428 option too.

Anyone who is wanting to upgrade their Chinese Pit Bike stock chain like I did with the Renthal R1 chain, several pages back in this thread, but not pay nearly as much should be interested in this chain.

When it comes time to replace my Renthal R1, I will definitely be going with this chain. Also, soon I am going to replace the stock chain on my wife's DB-X20 (pictured below), as well as change the front counter shaft sprocket to a tooth or so less, for more torque in 2nd gear.

It's a 17/14 125cc pit bike that has a Zongshen 125cc engine. It has inverted front shocks and a nice looking and working rear shock. The stock suspension is stiff enough to support my weight (195lbs and 5ft10) and it works really well.

The new Tire is a Duro (Brand). It's an intermediate tread compound, which is good for the area around me, lots of nasty sharp rocks, and hard packed dirt. This area will destroy soft compound tires quickly, even under the power of the Pit Bike.

I wanted the Dunlop Geomax MX52's (also an intermediate tire compound), but they didn't have any at Cycle Gear when I went in, they only had the soft compound MX33's and the guy said our local OHV park will destroy those soft tires very quickly.

I took the front wheel off two nights ago, so it would be ready. I wanted to be ready for when Terry from Redding All Terrain Tire Service called me up to tell me the front tire he ordered me, has come in.

Also, an interesting fact, the new tubes in the new tires hold air MUCH better than the stock. I have not had to add any air, and before, I would have to add air to both front and rear tires, every time I went for a ride.

The picture is all I have showing down trees. It's not representative of what I was actually encountering. The tree/branches in the picture was easily passable by just going around. There were many others I had to go OVER (wheelie over).

The main road (Fenders Ferry) goes about 42 miles before coming to pavement and eventually coming out on Highway 299E. (You can see in the 2nd map picture above my route, and where I turned around. It looks like half way between I-5N and 299E.)

I ended up going in about 15 miles or so, on Fenders Ferry, but this is not counting all the off shoots, I explored along the way. One of which, I had some trouble on, and had to end up breaking out the tools.

Just ordered a VM22 for my sons bike. We've been using Uni air filters, but resorted to the stock one a few weeks ago, as it's all we had on hand. Well, it let in a lot of fine dust, as it was very dry out, and my son ate a lot of roost. Since the stock carb doesn't allow for service, I really had no choice but to get a new one. Oh well.

So, I mentioned I had troubles with the kick stand. It was funny. I was about 3.5 miles off the main road (Fenders Ferry), when I was riding and climbing some steep hills, on this trail. It was this beautiful ridge (trail), and I was apparently unaware of how remote I was, while I was enjoying the ride. I was basically following tracks from, I believe, a Side-By-Side. I think the Side-By-Side had gone out exactly the same way as me, maybe earlier that day, or possibly the day before. I half expected to come up behind the Side-by-Side or possibly see it, on his way back from wherever the driver decided to turn around.

Kind of spooky, so I kept my eyes and ears peeled, and as quickly as possible I removed the large bolt holding the kick stand on. I only had a crescent wrench, so it was slow going, almost tedious, and a bit tense, but it got the job done. As soon as I was done, I tossed the kick stand in the back pack. I was relieved when the bike started. It did start easily, 1st try, as per usual. I quickly sped away, and got out of there.

None of the pictures I have, show just how steep and gnarly this trail was, in several spots. It just looks soft, cute, and cushioned with pine needles. When I was riding it, I remember wondering if I could do this trail, with my Suzuki Samurai with 6.5:1 t-case gears, with armor and cage, all aired down? It would be interesting!

There are actually 5 directions I could have gone at this one intersection! When I got to this intersection, I did not know which way to go. This intersection was a little over 12.5 miles out from where I started, which is almost 14 miles from the McCloud River Bridge.

In this picture you see my bike leaning against the tree (took pic after coming back from that trail I lost my kick stand spring on). You can see there are a total of 5 directions to go, including the one I came from.

Because of having to explore several ways, to rule out going the wrong way, and just wanting to see as much as possible, it meant I covered a lot of ground this ride. All the riding amounted to at least 40 miles. This makes me proud of the Little Pit Bike (LPB) that could.

Also, here are some cool pics from along the ride, Just a place I stopped along the ride. The creek was cool because someone had cut the log in such a way, that it made a perfect little table. So I ate lunch here.

One of the reasons I chose to buy it is because it seemed like a really good value for the money, for something new. This was especially evident when comparing to brand name bikes costing $1.5-4.5k. Some of these bikes in this price range were even years old and well used. Some would agree, that even well used and older, that those bikes are STILL better, which is arguably true. I just could not afford those prices for something that someone has already enjoyed for 10-years.

Another reason I chose to buy the X-Pro is that it could be registered with the DMV. So, it could be ridden legally off road, here in California. That's huge! You can't just buy anything and ride it here in California. It has to be at least Red Sticker, and then that is only legal some places, and only portions of the year, not year round.

I believe that Mikuni-clone carb does take a !-1/2" Uni filter, which is part# UP-4152AST. I usually oil the inner filter with PJ1 spray foam filter oil, and leave the outer foam dry. PJ1 also makews a spray filter cleaner, you can buy both together as a kit, as seen below. There is a biodegradable foam filter cleaner and oil that you can use soap and water to clean the filter, but I can't think of the brand name of it right now.

I looked up that part number you provided. That was awesome!. It does say 1 1/2inches (or 38mm), which helps me feel more confident it will work fine. I will definitely be ordering the UNI 2 stage air filter. Also, I did not know the PJ1 filter oil and filter cleaner was an option. Never heard of the brand, but I see they make all sorts of stuff. Thanks!

0.04mm is the same as .002", you use that setting on a stock 50 or 70 cc engine with smaller valves. It won't hurt anything at all to set the valves at .003" and .004". Just like it won't hurt to use an NGK CR7HSA spark plug instead of the A7TC the plate states.

I did have a dilema with the stock skid plate that comes on this bike. When I went to adjust the valves the exhaust valve cover access was pretty much covered by the skid plate, which necessitated removal.

It's excellent for exploring. I have gotten it into, and out of, all sorts of hard to get to places off road. 1st gear is nice (pretty low, but it can carry some speed too for powering up steep hills). It can crawl around very well in 1st gear, with a lot of torque as well.

The sleeves were cut to exactly the same size (width) as the engine mounts (both were different widths), so they ought to be fairly tightly kept in place, but maybe not. I am looking to make new ones when I find the right tubing (made from aluminum). It's 11/32 x .014 tubing....Comes out to 8.73mm. The bolt is 8mm so it slides into the sleeve easily, but with minimal looseness. Fits an 8mm bolt really well.

To go along with what was mentioned about different engines that do and don't require "rubber spacers with metal inserts", I have some pictures of the stock Zongshen 125cc motor, and what I attempted to do to emulate for the new motor. I found out later that the new motor measured out differently, and that it would not accept the rubber spacers I was trying to improvise with.

That's funny......Because, I honestly just thought some sort of rubber spacers were NEEDED. So much so, that I attempted to remove them from the stock 125cc engine to use on the new 140, only to find that they don't like to come out. Very stubborn they are.

Here is the motor fitted into place. The sleeves worked well, and the frame accepted the motor fine. I did have to widen the lower mounts with a bolt and heavy hammer just about 3/64". I had tightened down the stock motor before, and ever so slightly bent the frame mounts inward (imperceptibly), but enough to fight me when trying to fit the new motor. After I widened the lower motor mounts that small amount, the motor was able to bolt up, no problem.

You are talking about the DB-X29 front forks specifically, not just any general Chinese Pit Bike Upside Down Fork? Okay, well I don't intend to take them apart for some time, but I'd like to know all about them. Please, share your findings. If/when you take them apart again, please post pics, with all the details here.

Here is the main part of the connectors for the wiring loom. There is a rubber sheath or snout that hides all of the rubber water resistant bullet connectors. There were at least 3 wires that needed to be connected, with more auxiliary wires for other things like lights, etc. I do not remember all of the colors specifically that got connected together, off hand, but if someone needed I could certainly look to find out.

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