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HOW TO fix broken converter SP1 - SP2

29K views 24 replies 18 participants last post by  89659719955sa 
#1 · (Edited)
VTR1000SP1 or Sp2, RVT or RC51 in USA, has a converter unit to boost the electrical signal from the ECU to the pulse generator coils.

Item No1 listed here >>> http://www.bike-parts-honda.com/pieces- ... +RC51.html

This device gets two input 5Volt signals form the ECU (each for each cylinder), and sends out two 100Volt (or something like that) power signals to the pulse generator coils. The input logic goes like this, ECU sends 5V signal, and when a spark is needed, the 5V instantly becomes 0V, this tells the converter to send a 100V pulse.



The problem with the converter is that it sometimes fails. And the bike completely dies of ignition.

This can be caused by faulty generator-rectifier system with abnormal voltage output, or low battery voltage, so if your Converter died, check your generator, battery and R/R before anything else. If you don't repair the reason that fries your converter, it will be fried again.


A new Converter unit will cost something like 500 euros or more , which is not an easy price for everyone.

Here is how you or an electronics tecnhinian can repair it, at a cost of less than 10 euros.

In most of the cases, the converter unit elements that fail, are the ''high power'' output transistors.

These are two pieces of NEC 5P4M and two pieces of NEC 3S4M. Find them on a local electronics store, or order them on e-bay or elsewere. They are not very common and you might wait for some time for your order to arrive.

Once you have the new transistors, the repair steps are:

1.Dig the silicone material in the yellow area. Be very careful not to harm surface mounded resistor nearby. Remove the screws and the metal plate that holds the transistors.


2.Cut the broken transistors out. Leave the pins, as they can be used to easily solder the new ones on them


3.Solder the new transistors on, and put back the metal plate and screws.


4.Test the converter on the bike. If it starts and revs normaly, converter is repaired. Then put new silicon for water and vibration protection.


Ready, enjoy!
 
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#11 ·
I found the NEC 5P4M on Ebay but can't find any online store with the match for NEC 3S4M. Anyone know a link or a store name which has them?

My Stator, Regulator and Battery just died all at once. Pretty sure the CDI box won't be far away from failure so best to be ready.
 
#22 ·
Anyone else had any luck doing this recently? Tracked down down the both the thyristor and the controlled rectifier and will probably put them on order regardless of if I can find a good used CDI. Just wondering if anyone else has given it a go or if there is anything else I should look at while I'm in there.
 
#24 ·
I did the repair yesterday and it fired right up. I was having problems with no spark in the rear cylinder. front would fire and it would run off of one cylinder after I did this repair plugged it in and it fired right up.

Backstory is I was riding one day down the highway and lost one cylinder. No spark to the rear cylinder.

So now I want to find out why it would have fried it. when at idle battery shows 14.5 volts so i think all is working well. It does have a new battery so maybe an old battery fried it? anyone ever find out why their converter fried? I don't wanna dig all the silicone out because that was a pain.
 
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