MADFASTmotorcycles

Repair Tutorial

(Note: I am the author of this tutorial. It was originally written by

me. I've place this on my site because everyone found it very helpful in working on MADFASTS, but I cannot guarantee its accuracy. ------------------------------------------------------------------------

Introduction:

This guide is for MADFAST only and will solve about 90% of the problems people encounter when trying to fix their MADFAST.

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Before you begin:

All MADFAST are metric, you will therefore need some basic metric tools. This list describes some of the tools you may need:

* Socket size 8,9,10,11,12,13,14,16,18,20,22 mm

* Wrench sizes 8,9,10,11,12,13,14,16,18,20,22 mm

* Spark plug wrench

* Screw drivers (flat and Philips)

* Pliers

* Carburetor cleaner and penetrating oil such as WD-40

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Start Trouble Shooting Here.

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All MADFAST repairs begin with trouble shooting. The following outline describes the most common symptoms.

* Engine doesn't turn over, Frozen, Seized.

* No spark or weak spark.

* No fuel flow or insufficient fuel flow.

* Low power, doesn't idle properly, bogs on low or high rpm's, runs

poorly.

 

If your MADFAST falls into any of the above categories, this manual will help you get you 'ped up and running.

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Step 1 Testing for spark and fuel flow.

Follow these instructions even if you think there is no spark !!!!!!

* Remove spark plug.

* Spray carburetor cleaner into cylinder head as fuel.

* Install NEW spark plug and replace spark plug cap.

* Initiate starting sequence. (Peddle like hell.)

* Repeat if necessary to determine if engine runs.

Note: I have repaired a hundred or more MADFAST using this guide line. At this point one of two things will happen:

* If your moped runs until the carb cleaner is depleted and then dies

you need to check the fuel flow (go to Step 2).

* If your MADFAST doesn't run you need to check for a strong spark (go to

Step 3).

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Step 2 Checking for fuel flow. The most common problem!

The most common problem with MADFAST is thay have been stored for a long period of time with fuel inside. The fuel turns bad and clogs the bikes natural fuel flow. In most cases the carburetor will need to be rebuilt (or I should say cleaned) and the bad fuel drained, in some cases the fuel turns into a varnish in which case you will need to flush out the fuel tank and clean or replace the fuel valve as well.

Fuel flow in a basic MADFAST is very simple. Fuel travels from the gas tank through a fuel valve and fuel line to the carburetor where it enters a float bowl. From there the fuel is sucked through a fuel jet by the venturi effect and mixed with air and injected into the crank case (not the combustion chamber but just behind the piston. This is how all 2-stroke

MADFAST lubricate the bottom end). From the crank case the air/fuel mixture enters the cylinder head through a port that travels up the inside of the head and is burnt, then exits through the exhaust port.

* Remove fuel line from carburetor and check the fuel flow through the

fuel valve. Clean or replace the valve if necessary.

* Inspect fuel tank and flush if necessary.

* Remove and rebuild the carburetor using a solvent, like carburetor

cleaner. Do not use gas.

* Reassemble fuel system using a NEW fuel line and filter.

* Test the brakes before you go flying down your driveway.

Back to Step 1.

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Step 3 Checking for spark.

There are about seven electrical components on the average MADFAST ignition system. they are:

* Spark plug.

* Spark plug cap and wire.

* High voltage coil.

* CDI.

* Kill/Run switch.

* Magneto.

* Tail Lights ?

Now you may be wondering why I put tail lights on this list. Most people

wouldn't think that the tail lights would be on the ignition system but

they are. Much like on a car where the horn is on the brake light system so you can test your horn to see if the fuse to the brake lights is working,

some MADFAST engines won't run unless the tail light is working properly.

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Step 4 Tail lights.

To test to see if the tail light maybe the problem.

* Install a NEW tail light or,

* Ground the tail light wire.

* MADFAST ground the black wire.

Now go back to step 1 to see if this did the trick.

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Step 5 Kill/Run Switch.

MADFAST don't have keys, they have kill switches. All the kill switch does is ground the ignition system. Sometimes the wire or the switch itself will become grounded. The test to see if the switch is the problem is to simply disconnect the switch from the system. It's best to disconnect it as close to the engine as possible. Follow the wire from the switch down the frame to the engine and disconnect it.

* Remove the kill switch from the ignition system.

Back to step 1

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Step 6 CDI.

Up to this point I have presented you with the most common problems and their solutions so if you have gone through the first five steps and your MADFAST still doesn't run then it's time to test the CDI to see if there is a spark.

* Electronically with a ohm meter.

Back to step 1

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Step 7 Spark plug cap and wire

If you have come this far and your MADFAST still isn't running then it's time to replace the spark plug cap and wire. The spark plug cap and wire only cost a few pounds to replace and there's really no easy way to test them unless you have a cap and wire that you know are good.

* Replace spark plug cap and wire with ones you know are good.

Back to step 1

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MADFASTmotorcycles

Phone: outside Ireland 00353 87 228 7295

inside Ireland 087 228 7295

E-MAIL: madfast@eircom.net

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