FORMULA TKM 2-STROKE RUNNING INSTRUCTIONS

FORMULA TKM 2-STROKE RUNNING INSTRUCTIONS
The TKM BT82 engine will give many hours of reliable and consistent performance if it is looked after and treated in the proper manner. But it must be remembered that while it is a very reliable power unit, it is also a powerful racing engine and must therefore be treated with the respect such an engine deserves.
The information given in this guide is based on many years experience with the engine both in racing and on the test bed. We stress that use of excess revs and/or insufficient carb settings with less than 0.125 (1/ high jet opening will lead to reduced engine life.
Running-in must be carried out on a track and not stationary as engine will overheat!
It should be carried out for a period of 1 hour. Build up your speed gradually in 20 minute periods. At all times there should be a small puff of blue smoke from the exhaust when accelerating out of corners. If not, turn out the high jet accordingly.
Petrol Oil Mix Although we recommend Super Unleaded petrol for peak performance, it is quite acceptable to use premium unleaded. Do not use Lead Replacement fuel which is illegal. Fuel should be mixed at 16:1 Shell Advance Racing M oil. Mix 5 litres of fuel with 310ml of oil.
Plugs For normal racing, use the Denso W27ES-ZU spark plug. If running in very hot weather and at high load it may be advisable to use the W31ES-ZU plug. Plug gap for both is 0.025".
The factory recommended rev limit for sustained running is 14,800rpm. You are strongly advised not to exceed 15,750rpm as an absolute maximum. Although higher revs can be achieved this will be at the expense of power, and will substantially reduce engine life.
Carburettor The carburettor should always err on the side of richness for maximum performance and engine life. Settings are different between the junior and senior engine because of the use of the restrictor plate on the junior engine. Recommended starting settings:
Junior 128 kg Gold 20.5mm Restrictor
Low Jet 1.95 & High Jet 0.4 Turns out
Junior 136 kg Blue 22.0mm Restrictor
Low Jet 1.9 & High Jet 0.4 Turns out
Junior 142 kg Purple 24.0mm Restrictor
Low jet 1.85 & High Jet 0.4 Turns out
Junior Extreme 138 kg Purple 24.0mm Res
Low Jet 1.85 & High Jet 0.4 Turns out
Senior Extreme 148 kg No Restrictor
Low Jet 1.85 & High Jet 0.4 Turns out
For engines fitted with clutches you may have to reduce your advised Low jet setting by up to 0.3 turns and increase your High jet setting by the same 0.3 turns to get your engine to tick over correctly when engine is hot.
These are safe starting points which will give a slightly rich (safe) mixture. If the engine is too rich, then by using small amounts turn in the High jet until the carburation is correct. This will probably be between 0.4 and 0.2 of a turn out.
You can check the mixture by removing the cylinder head and inspecting the piston crown. Dry black is perfect. Dark to light grey is too lean and could lead to engine damage. Very wet and oily is too rich and will cause lack of power and possible fouling of the spark plug.
It is very important to keep your entire fuel system meticulously clean. If carb problems do occur they are often as a result of minute particles of dirt upsetting its fine tolerances.
Your petrol cans should be kept clean inside and swilled out occasionally. Filter your fuel through a funnel into the tank and make sure that the funnel is clean - keep it in a plastic bag when not in use. You should an in-line filter in the fuel pipe. Replace the in-line filter from time to time.
The carb must be spotless. If you have a problem strip and clean it through thoroughly, ideally using an airline, and finally put a little WD40 spray on the needle valve tip.
It is very important that the 'pop-off'' setting for the needle valve is correct. When tested with a carb pressure tester the needle should release at 10-12 psi and hold steady at no lower than 5psi. Adjust by carefully bending lever arm.
Exhaust The exhaust pipe flex length before installation should be somewhere between 60-100mm. The suggested starting point is 80mm. The longer the length, the more bottom end power and the shorter then the more top end power. When using an exhaust flex ring note this will effectively add 5mm to the flex length.
You should at all times use the approved TKM carb induction box. The foam filter incorporated into this helps reduce engine wear but does not reduce power if kept clean. If dirty, wash in Jizer or similar. Rinse with clean water and dry.
In wet conditions you are strongly advised to protect the air inlet to prevent water being sucked in. If the filter is waterlogged after you have been driving more protection is needed.
To guard against damage of the anodising on the head and barrel (which must remain) and the PVL TKM coil markings do not use heat or strong chemical cleaners including oven cleaners on these parts.
If using a clutch you should beware of revving the engine while stationary since this will place undue strain on the clutch and may cause it to over-heat. On clutch option specification engines a special sprocket and securing nut is available if you wish to use the engine in direct drive format where permitted.
On Off Switch Fitting to PVL Ignition
(Black in Colour as fitted to all new engines)
Connect a red wire from the switch to the short spare red lead on the PVL coil. Then take a black wire and connect it from the other switch terminal to the coil earth mount on the engine. Do not earth this wire to the kart chassis. Ensure both wires are of a suitable quality multi-strand type and tape or cable tie them to the kart chassis and steering column so they do not snag. You must allow sufficient length for steering wheel movement (and removal).
On Off Switch Fitting to Motoplat Ignition
(Red in Colour as fitted to older engines)
Leave the black coil wire as standard but take a new wire off the blue wire terminal on the coil and connect it to the ‘in’ side of the switch. Then run another wire from the other side of the switch to the coil earth mount on the engine. Ensure you use quality multi-strand wire and tape or cable tie them to the kart chassis. Allow length for steering movement.
Setting Ignition Timing
Using a metric dial gauge and adaptor, screw into spark plug hole with cylinder head attached to engine. Turn the engine to Top Dead Centre (piston at top). Ensure the gauge does not bottom out, adjusting as necessary. Set dial of gauge to '0’. Looking at the engine from ignition side turn the crankshaft clockwise to the desired reading on the gauge – eg 1.9mm. Check if the line on the ignition back-plate and rotor are exactly aligned. If not loosen the three bolts securing the ignition and rotate until aligned. Tighten bolts, re-check alignment.
Timing settings are:
Motoplat: 2.0 – 3.0mm PVL: 1.5 – 2.1mm BTDC
WARNING - The crankshaft is in three pieces and can be damaged by failing to adopt the correct procedure when tightening or removing the clutch / sprocket / ignition securing nuts.
You must never hold the nut at the other end of the crankshaft to tighten or remove the crank nuts. Use the special tools to hold either the clutch hub, sprocket or ignition while you use a spanner on the nut. This is vital to prevent crank misalignment.

CARBURETTOR SET UP
When using the clutch the carburettor must be set to allow the engine to tick over. This is done by setting the carb-mounted throttle butterfly adjustment screw and low jet. First using the screw under the carb, set the throttle butterfly slightly open so that you can just get the tip of a 0.6mm feeler gauge between it and the bore of the carb. This is the starting point. You should then start the engine. Tickover should be adjusted to about 5,000rpm. Make sure the clutch is not biting which will happen if the tickover is too fast. If so turn out throttle screw. If too slow the engine will stall. It may be necessary to fine tune the setting of the low jet to get a smooth tickover. If the engine is too rich it will not run smoothly on tickover when hot, turn the low jet in a little and the high jet out the same amount.

Taken From www.tal-ko.com
direct link http://www.tal-ko.com/PDF/Tal-Ko_Info_BT82_RunningInstructions.pdf

With thanks to www.kartingforums.co.uk

Please note in addition to the above, fuel and oil brands are free to choose as are spark plugs etc, however these details are straight from the tal-ko site so are the recommended brands for compliance with current regulations, but it is wise to check with the promoter you are racing with to be sure as some clubs will run a control fuel etc, good luck and always remember to play safe!