Monday, 1 March 2021

Testing Motorcycle CDI units and systems



Aprilia RS 125 for sale here on eBAY UK 



Aprilia RS 125 parts for sale on eBAY UK  




Testing motorcycle CDI units 












Learn more about these from this excellent video 





Sunday, 24 January 2021

Aprilia RS 125 How to test spark plug with multimeter to see if is it is good or bad



Aprilia RS 125 for sale here on eBAY UK 


Aprilia RS 125 parts for sale on eBAY UK 



Its a very easy but useful test to make sure your spark plug is ok , you may need to clean the electrode to ensure you get a good reading but all you then have to do is set meter to read ohms and measure from the spark plug cap end to the electrode tip , and then from end to body to make sure no leakage to earth.


Buy RS125 NGK spark plugs here on Ebay UK


How to test spark plug with multimeter to see if is it is good or bad

Get set up turn meter to ohms reading on dial and clean the electrode as below 

How to test spark plug with multimeter to see if is it is good or bad

Test between end of spark plug where HT lead cap fits and the tip of electrode the reading is very low only 1.2 ohms 

How to test spark plug with multimeter to see if is it is good or bad

on a dirty part of electrode the reading goes wild and eventually read 188.9 ohms so very bad and to avoid this clean electrode tip 



How to test spark plug with multimeter to see if is it is good or bad


Next test from spark plug cap end to the body to make sure no earth leakage your meter should read OL which is a good reading as it signals no leakage to earth via the body.

How to test spark plug with multimeter to see if is it is good or bad

See video of this process below 


Monday, 7 September 2020

i have an aprilia rs 125 2001 plate and starts and stops , i checked for a spark and i am only getting multiple sparks . what would be the problem ?






Q)  

i have an Aprilia rs 125 2001 plate and starts and stops , i checked for a spark and i am only getting multiple sparks . what would be the problem


A)  

hi , its hard to help when i d not know full story , is it a new bike that is never started properly or is just started happening ?


if your sure its spark then try a new plug first obviously then test coil , cdi etc .

test coil on input side see if its getting 12v to it .

starting then stopping could be fuel , have you cleaned carb out and cleaned jets out


Spark/Compression/Fuel/Air/Timing

You need all the above to get the engine to run.

Remove the plug, reconnect it to the HT lead, hold it on the cylinder whilst turning the engine over and you should see a spark.

Whilst plug is out do a compression test.

Check fuel is fresh and getting to the carb.

Check air filter is clean.

Unlikely to be timing but rs125s have been known to snap there own woodruff keys

Prob spark problem - duff plug , cap, ht lead, coil - prob not CDI but never know , timing slipped with woodruff key .

Try the obvious first and reply with findings!

Tuesday, 1 September 2020

Aprilia RS 125 Touch up paint

 Aprilia RS 125 Touch up paint 

Aprilia RS125 workshop manuals for sale here on Ebay UK



Aprilia RS 125 Touch up paints 


Product Specification

  • All our touch up kits consists of solvent basecoat colours and nitro synthetic clear coats.
  • Kits come complete with an easy to follow instruction fact sheet.
  • This kit contains a Basecoat colour and a Clear coat 2 bottles in total.



Aprilia RS 125 Touch up paint

APRILIA TOUCH UP PAINT MANA 850 RSV4R SHIVER 750 RS125 RS50 SPORTCITY GLAM WHITE

Aprilia RS 125 Touch up paint

APRILIA TOUCH UP PAINT 2000 - 2002 RS50 RS125 GREY METALLIC

Aprilia RS 125 Touch up paint

APRILIA TOUCH UP PAINT KIT RS50 125 250 1996 - 98 MIRAGE GREY SATIN.

Aprilia RS 125 Touch up paint

2 STAGE APRILIA TOUCH UP PAINT KIT 2007-2010 RS50 RS125 SPAINS No1 RED.

Aprilia RS 125 Touch up paint
2 STAGE APRILIA TOUCH UP PAINT KIT 2008-2009 RS125 TALMACSI REPLICA BLUE PEARL.


Buy these from Here on eBAY UK 

Sunday, 9 December 2018

Aprilia RS 125 regulator rectifier testing




You will need a multimeter with diode mode ( most have it )
Aprilia RS 125 regulator rectifier testing




Buy this DMM from Ebay UK here 








this is a bargain multimeter same as mine they are excellent .



The rectifier regulator converts AC output from the alternator into DC 14 volts to charge the battery 
. 14V is needed to charge the battery and DC is needed to operate the Coils and ECU without this the bike will not run .


The Rectifier is a package of diodes that only lets the current  through one way and block it from flowing the opposite direction .

We need to test each of these diodes in each direction and at the same time make sure they are not shorted .


Aprilia RS 125 regulator rectifier testing

Three yellows 2 reds one blue 
Aprilia RS 125 regulator rectifier testing
3 at bottom are yellow making it easy to id them 

Aprilia RS 125 regulator rectifier testing

Here is the wires 3 yellows from alternator 
are incoming AC lives the 2 outgoing wires red and 
red/green should be regulated and rectified to 14v~15vDC


The blue wire is the ground reference for rectifier and can be ignored for this test .



So basically we test between the red wire and then the red/green
to all yellow wires in both directions or polarities with multimeter leads



so to start with lets set the Multimeter to diode mode seeing as we are testing diodes we are looking for a voltage drop of 0.5~6 one way and nothing or OL in the other direction .


Aprilia RS 125 regulator rectifier testing

here i attach the red positive lead to the upper left wire in terminal 
block red and green , i then test between this and all the yellow wires with my black lead .



Aprilia RS 125 regulator rectifier testing

Aprilia RS 125 regulator rectifier testing

here i get a diode voltage drop of 1.083 volts i was expecting 
0.6 so a bit over could be sign of a failing rectifier .

Aprilia RS 125 regulator rectifier testing

so now i jump to middle bottom yellow terminal 

Aprilia RS 125 regulator rectifier testing

1.071 volt drop so its similar to above but still over expected 0.6v.

Aprilia RS 125 regulator rectifier testing

now move black negative lead the last yellow wire 
and i get 1.083 so a bit more than i expected but at the same time 
all readings are similar so i am not too concerned now 

Aprilia RS 125 regulator rectifier testing



Now i move the red positive leads over to the next upper terminal red wire 
and test between this and the three yellow bottom terminals again .

this time i get OL on all readings showing these diodes are functioning ok 
this side .

Aprilia RS 125 regulator rectifier testing

Aprilia RS 125 regulator rectifier testing

first yellow 

Aprilia RS 125 regulator rectifier testing

middle yellow

Aprilia RS 125 regulator rectifier testing

last yellow .



Now we have to do all the same above but in reverse ie with the negative black lead from multimeter connected to to the upper red and red green wires and touch the red positive multimeter lead to the yellow alternator wires .


as you see below attach black negative lead from multimeter to the top left terminal red/green wire and test between it and the yellow alternator wires with the red positive lead .

Aprilia RS 125 regulator rectifier testing

Now the middle yellow 
Aprilia RS 125 regulator rectifier testing

Aprilia RS 125 regulator rectifier testing



Now swap the negative lead of multimeter to the right side upper terminal or red wire and test with positive to the 3 yellows , you know drill by now.


Aprilia RS 125 regulator rectifier testing

Aprilia RS 125 regulator rectifier testing

Aprilia RS 125 regulator rectifier testing

all these are 0.552 which id say is more normal for these rectifiers .





Results as you see you should get OL one way and reading of 0.6v drop the other the fact this read 1.07v drop on some makes me think this is on its way out but to be honest this is the first one i have tested so do not have enough experience to condemn it plus this is from a running bike .

If at any time you had a short circuit you would get this reading in diode mode

Aprilia RS 125 regulator rectifier testing




to test the regulator is putting out the correct voltage just test at the battery , this test tells you the alternator , charging circuit and regulator inside rectifier is functioning good .

Aprilia RS 125 regulator rectifier testing



If you do need to buy a new Regulator rectifier for your Aprilia RS 



Tuesday, 8 May 2018

Aprilia RS 125 Ultimate workshop manual bundle all models







If you Donate £3.99 you will receive the Ultimate workshop manuals featuring all below

click here to Donate please and link for manual will be sent your Paypal Email .



Aprilia RS 125 Ultimate workshop manual bundle all models





PDF workshop manuals for the Aprilia RS125 , I have collected these over many years of owning an RS 125 .
Once purchase is made ill send a link to access the documents, manuals and videos via email , it should be within 24 hours.

Please add a message to say Aprilia so i know which one you want.

You can buy them all for only £3.99




Bundle includes
  • Aprilia RS 125 technical workshop videos x 9
  • Rotax 122 engine manual
  • Rotax 123 engine manual
  • RS125 owners manual
  • RS125 repair manual all 99>
  • RS125 wiring diagram
  • Engine start up advice
  • Clutch adjustment
  • Dellorto tuning & repair manual
  • Mikuni tuning & repair manual
  • Gearbox removal refitting guide
  • Oil pump set up
  • Timing set up
  • Engine split photos
  • Top end removal guide
  • Two stroke tuning guide
  • Piston diagnostics guide
  • Spark plug diagnostics guide
  • Sprocket mph calculator
  • And more



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please Donate below to receive your Ultimate workshop manual bundle