125-200cc WRE 125 Jetting Upgrade Acceleration Conundrum. I need a genius.

I'm completely out of ideas, google can't help me. I need someone with more experience. I purchased the derestricted jets and slide from husky sport for mega bucks after leaning out and destroying a piston last week. I rebuilt and reset the tps. Starts up and appears to run fine. But when pulling away in first gear, as I approach the rev range where it feels the power band is about to kick in the bike suddenly feels like its being restricted somehow. It sounds and feels almost like its on a limiter, but less consistent and building slowly. It is not a nice feeling. Then when shifting up to second it happens again, but then in 3rd I can easily work through it. From there up i'm in the band and it rides really well. It feels like it would be notably faster than it was but I'm too scared to take it there with the bottom end feeling the way it does.

I have tried adjusting the slide needle up and down a notch each way from center to alter the mixture, dismantled the carb again to check the jets are free from anything (despite being brand new), re-reset the tps, adjusted the float (clutching at straws)... but nothing. The new spark I put in two rides ago is on its way to dry black fouling, but could I put that down to feebaly put put'ing around trying to work out whats wrong? I thought it could be the power valve, but it moves freely when setting the tps.

Anyone have any more ideas?

Pop the original main jet back in and test quickly ! if that cures it you know the supplied one is to rich so you will need something inbetween the sizes.

Hello,

I am sorry to say this is how it is with the PU kit, I spent a huge amount of time and money trying to sort it. The only way you can fix it is to change carbs and go premix. Sorry for the bad news.

I own the wre, full dep pipe, when it was standard with the power valve it ran nothing like you say, however I did break a piston when putting the dep on as the jets were too lean for the pipe and my oil pump failed at the same time [or so the garage told me]. Can't advise on jetting but I can say I got told to suit the pipe they were told by husky sport to change the needle clip position on the slide, up the main jet size -I hear the number 140 in my head for some reason]. Now my bike runs great, has done for 4000 miles, it does bog slightly just below 6000 revs but it doesn't sound like what you say. However, the jet kit you purchased, was it intended to be used WITH a performance exhaust? All I can think is perhaps by jetting it up but keeping standard pipe you've just made it too rich to rev properly low down and once the pv opens it has more space to escape and thus you can ride it harder as there is more space for gases to escape for the extra fuel being pushed in. I'd check with husky again. Sorry I can't be of more help

just re read your comment about your spark plug, my last three spark plugs have not fouled at all, even at idle for five mins before riding [warm cylinder up] , but I did just read a black spark plug indicates overly rich mixture, which would go along with the derestriction kit actually restricting your performance

I'm not sure I follow all of the carb mods you've made, but I'm a big fan of keeping it simple when troubleshooting. Go back to stock jetting and see if it still is acting the same. If so, focus on the power valves, it sounds like they aren't opening at high RPMs like they should.

Does this engine behavior seem to be related to RPM or throttle position?