Yamaha DTR 125 CDI unit Questions
im asking on behalf of a freind.
on his bike he has a cdi unit that has no numbers or writing on it and we have a feeling its restricting the bike
It will fly up to 60mph but it will not rev past 8000rpm when the bikes moving but if he is sat in neautral and opens the throttle full it will rev to 12000rpm is there any chance this could be the CDI unit?
It has the YPVS System set up and a full dep system along with carbon fiber Reed's
there is no green or black wire and there is no reed switch as the wiring loom isnt in that year where they had reed switches
we dont know exactly what year the wiring loom is as it was swaped by the previous owners but they think it was a 1995-1996 loom, the bike its self is a 1988 but registered in 1989.... Any help on this would be fantastic... if you need more info please ask and ill get the info you need.
Pin the valve and try again. Sounds like the YPVS is retarding and limiting that upper power.
Cheers calum! we have tried this and makes no difference...
Possible reed switch related then.
Otherwise the CDI could be going faulty.
@Calum cheers calum, the bike has no reed switch on the loom no signs of the wires anywere, on my own dtr which is a 2002 my wiring loom isnt the same so this is why we are struggling as we have nawt to compare it too, and we cant compare it in the haynes manual as the wiring loom has been repaird due to old rotten wires etc... so im thinking it the CDI limiting the RPM but i wanted to get a second opinion
Could be any number of reasons.
Is the engine worn. Clutch worn out?
Is the powervalve actually operating correctly, I.E. are you pining it in the open position.
Does the bike have the round slide or flat slide carb? Looms differ markedly over the first 2 years and early looms have separate ignition control relay from cdi.
Right need some help please
Is there any way to find out if the 3rm-20 Cdi unit is okay?
the problem im having
Turn the bike on the power valve will turn to normal position but it dose not do the forward backwards cleaning cycle/movement when it turns on. It's the 5 wire power valve 2 wires go to the internal motor (black and red) (black and brown) and 3 wires (yellow and blue) (white and black) (white and red) go to the veriable risistor inside the power valve which is 7.5k ohms resistor
dose anybody know what the voltages out of the cdi unit should be while the bikes ignition is on for the powervalve side
any help greatly appriciated
@walney-reptiles it only does the full cycle when the engine has been running. If you power cycle the system two times in succession you get differing behaviours.
@calum other thing is when the bike was running the power valve didn’t move it’s not coked up or stiff as the top end and cables are all brand new just wondering if there’s anyway to find out if the cdi is goosed how can I check the signal from the cdi unit?
@walney-reptiles The servo opens at 6k to 9k and should be fully open at 10k.
So just because the bike is running, doesn't mean it's actually operating.
Not sure if the neutral switch tells the CDI not to operate. In other words, it has to be in gear and past 6K to operate.
Could be goosed, but again, just staring at it isn't going to make it move.