2003 DT125R tops out at 65mph ?

2stroketerry

Hi, my 2003 DT125R does 65mph at 8500rpm uphill or downhill in 6th gear. Fully working powervalve and reed switch moved well away from speedo, it has a dep expansion with an unknown silencer and a 3rm- 20 cdi. Any ideas ?

Calum

Have you tried just pinning the powervalve in the open position. If the reed switch has been removed then you should be able to get max revs. So it sounds like a PV issue to me.

2stroketerry

Hi @Calum when I turn my ignition on the powervalve goes through cleaning cycle then stops with notch in pully lined up exactly with the hole behind it. The bike is an import and supposed to be fully working powervalve, has plenty of power bottom end and can feel the powervalve come in around 7,000rpm. Just won't rev past 8500 or 65mph for some reason, don't know if silencer is holding me back and no idea what the silencer is just says 3MB on it. The hole in silencer is smaller than it looks from the side, should I get another silencer ?

finnerz89

Still sound restricted to me mate. Who moved the reed switch?

Calum

@2stroketerry Yeah I just want to rule it out bud. When the valve is lined perfectly with the exhaust port (I recommend taking the exhaust off and double checking, disconnect the valve completely from the loom so that it cannot operate. Then go and take the bike for a blast up a dual carriage way. Should pull hard to the red line with compromised power below 6K. If that's the case, then you know the PV isn't setup probably.

Jens Eskildsen

Some upjet a lot with a different exhaust, eventhough its rarely needed.
How big is the mainjet? Try a stock sized.

declan

@2stroketerry I found out when the pv is lined up with the hole it’s not correct it’s still part closed so as @Calum says take the exhaust off and do it properly

2stroketerry

Hi , yes going to do what @Calum said and remove the exhaust and make sure fully open then unplug my servo from the harness. Can't do it at the moment as my bike is outside and it's -4 and snowing so will have to wait for better weather, my girlfriend won't let me bring it in the kitchen to work on it. She went mad the other day when she got home and found the kitchen table and chairs all took apart, just need to bribe her.lol

Calum

@2stroketerry Some girlfriend....Tell her I said that by the way

2stroketerry

Yes @Calum terrible and I bought her an Astra for xmas top of the range Elite that cost me £7000.

2stroketerry

Wanted to treat myself to this to replace crappy shed she keeps her lawnmowers etc in but can't have it she said as takes up too much Lawn, garden mad she is so all I get is a bit of patio.lol
https://www.gardenbuildingsdirect.co.uk/wooden-storage/billyoh-28mm-premium-motorbike-store

Sgt Robuck 5

dump her mate XD

Irongamer727

Agree, it's for the best.

terry.tz

its never going to work out :face_with_tears_of_joy: :face_with_tears_of_joy: :face_with_tears_of_joy:

Calum

Oh dear, back on topic anyhow....Let us know how you get on with the PV. If it still struggling then it would sound like it's still restricted and needs sorting ASAP! 2003 models were the WORST for restrictions!