High rev upon start up

New to the blaster game. Bought this blaster (of an unknown year) 2 weeks ago. Was told it needed a new kickstart which turned into it had no compression. Replace top end and upon start up with choke engine revved higher than what I would call normal, with choke removed it revs sky high. Immediately killed it and started reading. I’ve made my homemade leak down tester and leak tested and found both crank seals leaking. Replaced both crank seals and re leak tested and it passed, holding 9psi for well over 10 mins. Put everything back together and still same problem. Replaced carb still same problem. Air screw is backed out 1 1/2 turns and has no effect on rev when testing. Tors delete kit on the way. Bike to my knowledge has an fmf pipe with bills pipe silencer, vforce3 reeds, saw hot rod written on rod when replacing top end (not sure if relevant) running a 25:1 fuel mix. Could jetting be an issue? Has 230 main jet with needle in third setting from pointy end. At witts end with this. Bought my son his first 4 wheeler (he’s 16) and he can’t even ride it. Any help is appreciated.

Larry's Shee said:

Did you do a leak down test after assembly? Retorque after heat cycles? Did you use cheap Chinese junk parts?

Click to expand...

I leak down tested after assembly and haven’t ran it really long enough to put it through a proper heat cycle but I have rechecked torque on both jug and head.

I should also note that if choke is off and it’s revving high I was able to bring it back down by covering breather tube on intake box. Only did this once and didn’t have it running long (really not trying to mess anything up) I also have old oil injection port in carb capped off

Throttle cable is routed correctly. Needle is in correctly with slide in correct position. Tors idle screw seems a little fudged, it just free spins either way ( doesn’t feel like it’s grabbing threads) but I do have tors delete coming. I appreciate the advise on the oil/fuel mix. I will be changing to 32:1 on next tank. Slide looks to be more than an 1/8th up. Maybe closer to a 1/4.

Side note: your posts from the past awk08 got me to where I am now in regards to checking everything I have already checked so thank you for that!

Update: Vito’s tors eliminator kit arrived and is now installed. I also jetted the carb with Dyno jet kit dxp 220 main and needle that came (clip in third space from top)with kit. Followed direction of jet choice (stage 1)accordingly due to have after market silencer/exhaust. Now have new issue. Bike will not start without throttle pressed and will not rev when throttle is pressed. Tors brain is unplugged and plug at throttle is remove and plug at carb is disconnected. Any help is appreciated!



Side note: high idle I believe was caused by broken throttle cable previous owner wrapped in electrical tape as a repair. Blended in nice would’ve never saw it if I hadn’t removed it

Update: replaced jet with 290. Still can’t get it to idle and when I get her throttle it will not rev it boggs under throttle

Update: my dumbass left the pilot jet out. I’m ashamed to admit it but it was a learning experience to not work on carbs sleep deprived. Bike is currently running and is ready to be broken in!!!

A year later update. Cheap Chinese top end main bearing exploded when my son ran it down the driveway the first time, it cracked the case internally. After it sitting for four months due to frustration we got to work. Pulled case apart and welded and smoothed crack, new weisco bottom end and top end. Found swing arm was booger welded together so bought the vitos chromoly +4 one. All new bearing in rear. New sprockets, chain, pulled it completely down and repainted. So in short a top end rebuild turned into a frame out resto. Son loves bike and it’s one of a kind. Thanks for all of y’all help. White pic is before pic. Black is after