Ralphch97

Anyone have any ideas?

Didn't mean to write twice and won't let me delete, sorry!

I'm clueless cleaned carb, changed plug, cap, and checked my friends coil on my bike to see if it was that, nope! Got a friend to check if my power valve was set up properly, and working, yes it is, But the bike still won't rev past 7000 intact now it's not really revving past 5000-6000! If I pull clutch it and blip the throttle like crazy for about 30 seconds I can Manage to make it Rev up! It's struggling to do 40mph! And just runs like.....

All set correctly! Don't run inline filter! I'm going to clean the carb out again! So I can double check if it's that! And I'll start using an inline filter once sorted! So annoying just want it back on the road! Thanks for all help! I'll keep you updated in next few days to see if it was a carb problem!

At first I thought it was the carb so I stripped it apart and cleaned it, issue still occurred, and it revved freely before up to red line if I wanted to! So makes me think it's not cdi! It's gets to around 6000-7000 depending on gear then splutters and just won't Rev anymore, defiantly doesn't go into the powervalve! and no, I don't have another cdi to try Also throttle is fully open as well, I had ago at holding it their for 20 seconds but nothing happened and just made me worry id cause more damage!

Actually hold on, Yes it is aligned up! I thought you meant the bolt that holds the pulley on, It is aligned with that small hole.

I will post a picture of it and maybe even a short video tomorrow, as its dark outside now and no lights in shed! I understand what your saying now though so ill have a better look tomorrow, Thanks for your help!

I took the power valve cover off and the cables have a nice amount of slack, and I just watched a video on YouTube of a power valve servo set up properly, and mine looks and reacts exactly the same, (Not really sure how to explain how its the same, but all the cables are in same place, and when I rev it, It moves back and fourth the same way and positions its self how it should) Sorry about explanation, I'm okay when it comes to carburettors, and other basic stuff, The power valve just confuses me!

Yes the Power valve does its cycle when I turn the ignition on, A mate has told me it might need adjusting again but how can it just suddenly change adjustment? Cables were replaced in November! thanks for reply.

Hello, I was wondering if anyone had the knowledge to help me, I have a Yamaha DT 125, I have owned the bike since December and it hasn't missed a beat until last week when a rev problem occurred. (The bike wont rev past 6000-7000 RPM) The bike is fully de-restricted, hence the CDI but I know its not the cdi as it revved smoothly and freely until the other week. The bike has the Athena 170CC Top end, Dep pipe, PV Servo connected up and all jetted properly by a garage, I know the issue isn't carburettor related as I have stripped and cleaned it, Also I have given it a full service but it still occurs. The complete engine was rebuilt in November 2014 by a garage, this has receipts and I even phoned the garage that carried it out before purchase, The compression is good, The bike has only covered 700 Miles since, Running Pre-Mix on Fully synthetic Motul 2 stroke oil, Always maintained, So shouldn't be engine related. (Other than YPVS?) I am wondering if the issue is YPVS Related? Thanks - Ralph.