Welcome to the technical guides page. Here, you will find guides on maintaining your air cooled bike, fitting parts, and modification help.

Cags need to be regularly maintained, and are great out of the box. To add to that effect, many people choose to mod their cags to get more speed out of them. Below, is a list I have formed of mods in which I think is worth buying in order, in a list of 6. 1 being the best.

1.

Big bore kit: This is an upgrade from the 47cc engines that have a 40mm piston. The Big Bore kit supplies a bigger cylinder, in which to fit a bigger piston at 44mm, gives you a true 49cc engine. This upgrade is well worth buying and has a high impact on performance. If your engine is already the rare 49cc, then buy the big bore kit that comes with a dome on top of the cylinder (torque head).

Pic

2.

Race exhaust: This is best used in conjuction with the big bore kit. The exhausts are of much higher quality than that of the standard ones. Although these can prove tricky and annoting to fit, they are a great mod. The expansion chamber on an exhaust is what matters. This is the larger section of the exhaust pipe. The larger the expansion chamber, the more fumes can get in and the quicker they can get out.

3.

NGK Spark plug: These performance spark plugs are far better than the standard chinese plugs, and are made of a high standard. These plugs spark more effectivly and and fires a lot better, burning fuel more effieciently. These also increase compression in the engine and can start bikes better after stood still for a while.

4.

2 Shoe Adjustable Clutch: The 2 shoe adjustable clutches are a big improvement from the standar 3 sho clutches. You can adjust these to engage later. Tightening them will result in them biting at higher revs therefore giving you good acceleration, loosening them witrh make these bite at lower revs resulting in higher top end. This is a copy of the polini 2 shoe clutch, and will require a bit of tinkering to set it up right.

5.

To add to the effect of the exhaust and the bigger engine, a bigger jet will probably be required. The bigger engine need more fuel as it has a bigger piston. The exhaust can take in more fumes and also exit them quicker. This can be taken to its max to get more speed. It may be more fuel consumption, but it can make the bike go faster and run smoothly.

6.

Another add on to the exhaust, engine and jets, is a performance air filter. The bike has a mixture of fuel and air. By adding a bigger jet, there will be more fuel going into the engine, therefore, un evens the mixture of fuel and air slightly. Apart from the fact that the performance air filters are of better quality, they also let more air in, therefore matching the fuel mixture. This is why you may need to change the jets a few times to get the mixture right.

 

The guide below was written by Wardo, from www.cagclub.co.uk

 

BIKE NOT STARTING OR RUNNING?

Sometimes, especially when new. Cag bikes are a real pain to get running for the 1st time. If you are having this problem, then please refer to the tips below and your Cag should be running smoothly. Dont forget, that every Cag that leaves the factory Should and more than likely will start if set up correctly.

1. INITIAL CHECKS AND FUELING After assembly of the bike, make sure there is no factory debris that may clog up fuel lines in the fuel tank. Sometimes there are bits of excess plastic in the tank. This needs cleaning out straight away. Next, check that you are mixing the correct ammount of fuel. The bikes should be RUN IN, to a mix of 25:1 of Unleaded and Fully Synthetic 2 stroke oil. If this is not done correctly, you mak have problems starting and running your bike.
With the mixing bottle, you will see the markings for a mix of 25:1 (see image below). Fill up to the horizontal line with Unleaded (marked with green), and then TOP IT UP to the top of the vertical line (marked red) with 2 stroke.

This will give you a mix of 25:1
Once the bike is run in, approx an hour or so of constant running, the fuel mix can be changed for a more leaner 40:1 or even 50:1.

2. STARTING Initially starting the bike is difficult in some cases. First of all check that there is fuel visible in the fuel filter, if so then make sure the it is in a position so that the fuel can run through it, i.e not sitting horizontally. If its not sat correctly then fuel will not get into the carb. If that is ok, then next we look at the fuel tap (the white 'twist' tap). To turn the fuel on you need to turn the tap, so that it sits vertical, in line with the fuel pipe. If it is sat horizontally then the fuel cannot pass into the carburettor.
Now, next comes the Choke. In the Mk1 and Mk2 instruction books, it tells you that the choke is off (allowing a fair mix of air and fuel for general running) when it is pushed up, and closed (not letting as much air in, so the fuel fires better for starting) when it is pushed down. Well its wrong. Its the opposite, Up for starting, and down for running. So make sure its up to start with.

Now comes the starting. To start the bike, it may take a few pulls of the pull start, and possibly a little throttle. It should fire up and run if all above has been done correctly, however there are a small few that dont, and need a bit more attention. Try starting it with the choke in a few different positions to see if that starts it. If the bike is now running, leave it to warm up for a few moments, then close the choke (move it down) and ride off.

If your bike has not fired and started... you need to read on.

Check that the IDLE SCREW (the small brass screw on the side of the carburettor) is screwed right in. This will mean that once the bike fires it will rev right up, getting plenty of fuel and oil through the system. Once it has started, you may adjust the valve so that the bike sits at a nice idle speed, WITHOUT the back wheel spinning round. The idle screw is missed by many, and could well be the cause of you bike not starting due to it not being screwed in enough! Try this screw in various positions.

The next thing to check, is that there are NO kinks in the fuel line. Even the smallest kink can make the fuel flow poor, and not be enough to feed the carb. You need to eliminate any kinks in the fuel pipes by either adjusting them, or cutting and altering them. After you have done this, try starting the bike with the above methods again.

Still not starting? It may be a faulty spark plug. The standard spark plugs are very poor and offer a very poor ignition spark. Sometimes this alone can be the cause of a bike not starting or running correctly. To change the spark plug, you will idealy need an NGK BM6A spark plug. Champion offer an alternative to the BM6A which is just as good. To find out how to change your bikes spark plug, then read below for the spark plug changing guide.

If it still isnt starting, (USE AT OWN RISK) it may be worth trying to start the bike with some Easy Start. Easy Start is a highly combustable liquid that will burn even with a poor spark. Its available from most petrol stations for about £4 a can. Spray the Easy Start onto the air filter. Try and get it in behind the housing of the filter for optimum results. Spray it in bursts of about 2 seconds, and then try starting the bike. Now it should either start up and run, OR it will start up and run for a few seconds, then cut out. This means the engine is burning only the easy start and not the fuel... the problem lies elsewhere.

The guide below was written by Wardo, from www.cagclub.co.uk

FITTING A PERFORMANCE AIR FILTER

 Fitting an upgraded air filter can help your bike breath better, run better, and also LOOK better. Heres how to fit one to your Cag...
We are unable to supply info on fitting one to a MK3 Cag, as the rear frame assembly is different, making it difficult to fit one withouth further modifications to the bike! Look out for a guide coming soon for the MK3!

It may be an idea to remove the rear wheel assembly to fit a new filter, but this is not neccessary and is more work than needed, if you have a small posi/phillips screwdriver or allen key (whichever holds your standard filter.

First of all, you need to buy an uprated air filter, and velocity stack (base). The one pictured below is what an uprated air filter looks like, they do differ from make to make.


Next you need to unscrew the standard air filter off your bikes carb. To do this, locate the 2 screws either side of the filter housing and un-screw them. Once the screws are fully out then the air filter housing should pull off. This should leave the air intake open, so you can see the internals of the inlet i.e the choke.

Next you need to fit the upgraded air filters base, or as some call it, the Velocity stack. This should just screw on using screws provided with the new filter, Make sure they are nice and tight. Now you need to fit your filter. Most filters fit with the use of a Jubilee clip to hold it tight onto the base. Unsrew the jubilee clip so that its loose on the filter. You now need to push the filter onto the velocity stack. Make sure its on correctly all the way round, and then tighten up the jubilee clip, so that its tight and the filter will not pull off.

Thats it.. Job done. Your bike should now look like this:



If you are going to be using your Cag on the track, or if you notice its not quite runing as well as it was, You may need to change your carb jet. To learn how to change your carb jet, look below and find the guide to changing a carb jet.


The guide below was written by Wardo, from www.cagclub.co.uk

 

FITTING AN ADJUSTABLE CLUTCH

 Fitting an adjustable performance clutch is a good performance upgrade. It allows you to set where the clutch bites, and at what engine RPM. The higher the RPM, the better the bike will accelerate. Here I will demonstrate how i fitted an adjustable clutch to my bike. Your bike parts may differ slightly to my bike!


STEP 1: You need to have purchased an adjustable clutch. They are available from around £25 - £35, depending where you look. I got one off eBay for £25.

An adjustable clucth looks like this:



STEP 2: You need to remove your bikes fairing, and chain guard to get access to the clutch bell and its housing.



STEP 3: You now need to remove the clutch bell, and its housing. This is simply done by removing the 4 bolts that hold it on. You will either need an 8mm spanner or the right size allen key (dependand on which type of bolts hold it on)
I had to use an 8mm spanner to remove my housing.



STEP 4: You now need to remove the clutch. This can be tricky. You need to wedge the clutch with a screwdriver so that it doesnt spin. Then you need to undo the 8mm bolt holding the clutch on. This can take some force to do. If the clutch is just spinning, you need to wedge it better. Make sure the screwdrive is pushed right in so it holds the clutch still while you undo the bolt.
Demonstrated here:



STEP 5: Next you need to remove the clutch, to do this, give the clutch a couple of solid knocks with a pair of pliers to try and loosen it slightly, then just wedge a screwdriver behind it, and pull it off. It may take some effort but it will come off. Next you need to remove the woodruff key thats sat in the slot. Keep this handy because its the same size as the crank key that turns the flywheel, and its always handy to keep a spare!



STEP 6: Now its time to fit your new clutch in place. Push it on, and screw the 8mm bolt and washer back on as tight as you can. Do not overtighten this because if you thread it, it may not hold the clutch in place tight enough, which may cause problems. Once its on, make sure that when you turn the clutch, you can feel the engine turning.



STEP 7a: At this point, its worth re-building the clutch housing, putting the chain back on and testing the bike to see where the clutch bites. You must RIDE the bike to test it as it may turn the wheel when your not sat on it, but as soon as you sit on it it may not be engaging enough to pull your weight! you dont need to re-build the whole bike to test it!



STEP 7b: Now its time to set the clutch up if its not biting late enough. Using the 2 nuts on each end of the spring, tighten them up a little. Only make small adjustments. Tightening the nuts, puts more pressure on the springs making them harder to oull out when the engine is turning. Only when the engine is turning fast enough will it be able to make the clutch bite. You are aiming to make the clutch bite at a fairly high RPM. This will allow you to accelerate at a much faster pace, as your engine will be turning the wheel harder. Try and make sure that the 2 clutch pads are biting evenly. You can tell this from slight wear marks made on them when testing the bike.



STEP 7c: You need to repeat STEPS 7a and 7b untill you have it set up to how you want it!


STEP 8: Once you feel you have got it how you want it, rebuild the bike!
 

FITTING CARBON FIBRE REEDS