| It is common these days to see mini bikes being sold in | | | | performance benefits will not be as evident. |
| stores already with performance parts fitted, such as | | | | With these changes the bike should have better |
| K&N style air filters and performance exhausts, | | | | throttle response with better acceleration and also |
| however there is always still more work to be done to | | | | higher top end speed. This works very well with the |
| these bikes. | | | | performance exhaust and the extra performance with |
| They are incredible easy to work on and with such a | | | | the bike should be easily recognisable. |
| basic engine the only knowledge needed to work on | | | | Once the Mini bike has been up jetted and a free flow |
| them is knowing how to use a spanner or a | | | | filter and new carb have been fitted then it is time to |
| screwdriver. | | | | make some smaller adjustments to fine-tune the bike. |
| Here is a list of modifications recommended in order to | | | | The next adjustment which could be made to the bike |
| increase the overall power of the bike, as well as | | | | would be to add a rocket key, this allows the bikes |
| improving the handling and feel of the bike. | | | | timing to be improved for pulling away and |
| It would be an idea to start modifying the mini bike with | | | | accelerating, meaning that the throttle response and |
| the larger mods, as with these more performance is | | | | acceleration will be improved. |
| gained for the money spent. The biggest modification | | | | It is also likely that the gearing of the bike will need to |
| which can be done to a Mini bike is to get it bored out | | | | be changed depending on where it is used. This is |
| to a larger engine displacement. Most of these bikes | | | | mainly done through different sized sprockets, and this |
| will come with a 47cc (which is actually only 39cc). | | | | will be changed depending on how the rider wants the |
| These engines can be bored out with a racing kit to | | | | bike to perform |
| 49cc. This will improve the power of the engine due to | | | | If a larger sprocket is put on the front or rear of the |
| the larger displacement, improving acceleration and top | | | | bike then the top end will be improved whilst making |
| end. | | | | accelerating slightly slower, however if the Mini bike is |
| If the mini bike is already 49cc there are kits for sale | | | | fitted with smaller sprockets then the acceleration will |
| which take the engine up to 58cc again having the | | | | be improved whilst losing some top end. These |
| same effects as before. | | | | sprockets can be changed depending on what track is |
| The next modification it would be wise to make to the | | | | being raced on. |
| mini bike is with a performance exhaust, these come in | | | | Due to the modifications made to the bike to improve |
| many makes and models and each style will have a | | | | performance, some other changes will need to be |
| different output to the next, so it is best to look around | | | | made to the bike so it can cope with the extra power |
| before jumping in and buying one straight away. | | | | and maintain that good performance. Items such as an |
| These exhausts work as they have an expansion | | | | NGK spark plug or similar could be used. The standard |
| chamber, which improves performance on any | | | | plugs in Mini bikes are not very reliable and will not be |
| 2-stroke engine. These exhausts are not usually over | | | | able to cope with the power the bike is producing. |
| expensive; the cheaper systems can be bought for | | | | Also doing this will improve the starting of the bike as |
| under £50, and go up to over £200 for | | | | well as keeping the bike performing at its best all the |
| the more expensive systems. These are great bolt on | | | | time. Whilst changing this is it also a good idea to |
| performance parts, and can improve the acceleration | | | | change the lead and coil going to the spark plug for |
| of the bike with higher low and mid range revs, whilst | | | | maximum benefits. |
| increasing top end by up to 10 mph. | | | | Another aspect of the Mini bikes which could be tuned |
| These exhausts will really benefit the bike if it has | | | | is the clutch system. The clutches on the bikes are |
| been bored out as well and the difference in | | | | automatic centrifugal clutches, which will wear very |
| performance will be evidently noticeable. | | | | quickly if modifications are made to the bike. It is |
| The next modification which could be made to the | | | | advisable to upgrade the clutch to a heavy duty clutch |
| carburettor, and increasing air flow through the bike. | | | | with heavy duty springs, these will last a lot longer and |
| Firstly, add a free flow air filter,(K&N style ones). | | | | also can improve acceleration and throttle response of |
| This will mean the bike can take in more air, and the | | | | the bike. |
| rule of thumb for any engine is - increased air intake + | | | | With all this power now added to the bike it is |
| increased fuel flow = increased BHP. | | | | advisable that you make changes to the brake |
| Therefore this part will help with the performance of | | | | systems on these bikes. Most of them come with half |
| the bike, however if an air filter is fitted then the carb | | | | descent disk brakes anyway but upgrading the brakes |
| will need to be up jetted in order to cope with the | | | | may be a good idea, imagine racing around a track |
| extra air, performance is likely to decrease if these | | | | doing over 50 mph, and then coming to brake and the |
| changes aren't made. Buying new jets for the mini bike | | | | brakes just ain't man enough to handle the speed, this |
| increases performance as these jets will allow more | | | | is why this change is recommended. |
| fuel to be sent through the carburettor. Tuning will need | | | | Once all this is done the bike will have been modified a |
| to be done with this to get the air:fuel ratio correct. | | | | great deal without going too mechanically into it and |
| It is recommended that if modifying the air and fuel | | | | the extra performance of the bike will leave other |
| intake of the engine that a carb upgrade is purchased. | | | | bikes standing. |
| The standard carburettors in these bikes do not have | | | | Just remember to always ride on Private land with the |
| as many adjustment screws as the performance | | | | owner's permission and wear protective clothing. |
| carbs and therefore cannot be tuned as highly, and the | | | | |