Sluggish until powerband



  • So recently got pv working, since that its been gutless until it hits powerband, its alot like turbo lag, revs to 6k ish, theres a few seconds where it doesnt want to go and then she flys. Also in 5th she will do 60,change to 6th add does 50mph. Carb settings maybe?



  • Are the cables set up properly? Sounds like my bike, yet i don't even have a servo. So i'd check it's all aligned, i'm sure Callum will be along in a minute to tell you how to check it all. I haven't gotten any experience with it



  • Didn't you say you have a big one expansion chamber?

    I'm confused you keep changing the story 😕

    Sounds like the powervalve is not opening and closing properly. I have a video on YouTube of how the valve should operate properly. It's a fairly simple procedure. The important part is making sure it opens up fully.



  • Its a big one end can, but I bought a big one expansion which will be going on today. It does open fully, it's just really hesitant, and high up the revs



  • @DevonDtr Yeah well done mate it would be! Remember I was telling you about the restricted CDI. The powervalve retards at the higher rpm shutting off the exhaust port suffocating the engine.

    But you said you didn't want to derestrict the cdi.



  • Yeah changed my mind now lol I will derestrict it. Fitted big one expansion which has made no difference except noise



  • @DevonDtr Suggest you do some reading up on 2stroke tuning, Carburettor tuning.

    DT's have a very linear power feel for a 2stroke 125cc. If your experiencing 'lag'. It would seem your mixture is off 'too rich' in the mid circuit.. 'if your 'powervalve' is working as you say.

    Read up on the 2stroke engine if this is your first, it sounds like your bike needs to be jetted. It's all really simple stuff, and great knowledge.

    99-03' DT's onwards are restricted as callum mentioned after 8,500rpm. So if it's not going to 10k+. That's because it won't.



  • @DevonDtr Yeah the big one expansion chamber is not the best from what I had read. The dep will give a huge difference in performance.



  • So if possible can somebody explain how to adjust the powervalve? I assume it's the 2 cables going in



  • @DevonDtr you need to determine that it is the valve causing the issue. Or is it something else.

    With the exhaust off. Turn the ignition on and off and watch the powervalve open and close the port. It should open completely with no step.

    If it hasn't then you need to adjust the pulleys until they do.

    If you take off the powervalve cover you will see a hole in the cylinder, and a hole in the plastic powervalve lever. They should line up. But due to parallax I prefer to use the other method.



  • Done that, it lines up and goes through its sequence with no struggles. All cables are clean and it looks like a brand new pulley