DT125 R YPVS Fault

[Ardy]

A friend of mine is rebuilding a 2004 Dt125re, the bike was bought as an incomplete project the engine fitted is a 4GW which I think is a TDR.

The engine runs and sounds sweet but the only problem we have is the YPVS system dosn't work, It originaly came with a 3 wire servo that didn't match the loom, so we aquired a 5 wire plugged it in, nothing,

The wiring loom looks to be the original and we've checked it for condition & continuity.

What I do want to know, is if there should be power to the YPVS servo when the ignitions turned on, so that it can go through its cleaning process, if so ,where does the power come from ? my guess is the cdi unit.

The CDI incidently is situated under the fuel tank and is secured with a rubber band affair, three plugs go to it, one of which is the YPVS servo. Could it be the wrong CDI unit.

Any advice would be great.

Ardy

[kenDAWG]

have you tested the wires to see if there is power going to the servo while cleaning process is done? do you know if the servo worked before you tried it?

get the numbers off the cdi and see if it is correct for the engine/servo

[NEV]

I think that's your problem right there mate, you have a 2004 bike with a 4GW4 1996 ish, engine, the 2004 bikes had a 5 wire powervalve servo, whereas the 4GW engine had a 3 wire 4FU-85820 powervalve servo, I'd go with the 5 wire servo as that is what the CDI on the 2004 loom, will be geared up to take.

[Cynic]

But tje 96 motor is designed to work very differently. That motor can comfortably make 20 pluss hp de restricted PROPERLY with the right electronics.

It wont like the 5 wire servo much as that gives a big wide rideable torque spread. Getting an older cdi working would be a better bet. Even at the expence of newer parts.

This is when you need vez to confirm it but i'm 99.9 per cent certain of this.

[Ardy]

Thanks for replies.

Becaue my bike has the original CDI unit fitted and would have been geared up for the 5 wire servo, will I have to change the CDI to operate the three wire? If so is a straight swap.

Having done some research it appears that you can just simply give the three wire unit an ignition feed and then a pulse from the CDI and it should work, gave this a go, can now get the unit to go through what would be the cleaning process, but cant get it to move when increasing the revs, Anybody know where to pick up the pulse? it should be according to what I've read via a yellow and blue wire from the CDI but this is not the case.

So this is whats leading me to believe the CDI unit has to be changed.

Any Ideas

Ardy