125-200cc Building new race bike

ive had maxpower rpms do my engine in my yz250 and it was nothing short of perfection
turn around time was a little longer than expected mostly due to some OEM yamaha parts that were backordered but they shipped it back and i put it in and it was nuts, the engine was amazing and ran (and still does run) like it is brand new, id spend my money there again in a heartbeat

My WB165 ain't going anywhere, I was just wondering what the differences would be with a couple more cc's .

I know. Like I can use even more power! Like John said though.....wonder what the extra few cc's would be like? Someone get it done and post a ride report! Who is going to be the guinea pig??!! Or should I say.....who is going to spend the money!

Hot Damn!!! 1700!!!

WB165 = more bang for the buck !

Instead of riding 1 gear higher, you will have to ride 2 gears higher!

I say start with the WR125, put on the 144cc kit and send off the 125 topend to be converted to 165cc. You will have the larger tank and 18" rear wheel already. You will also have the ability to install lights if you like. Mine has the larger flywheel and I wouldn't change it for anything. Tons of torque and I rarely ever have to touch the clutch except for shifting gears and stopping.

Hey, i have been reading quite a bit about the WB 165 kit and was curious about how far out it would put me?

How far out in front??? quite a ways!!!


Or are you talking time setback for shipping? If so, contact Kelly at Motosportz to get a solid answer.

Haha! Well that's always good to hear. I appreciate the feedback on the shipping time, but was also curious about price too, ( sorry could have been more specific the first time).
Again thanks for the responses guys, i'm still debating financially more than how awesome it is!

I,ve put out a couple of videos of my 09 WR125 with the WB165 kit,so you can have an Idea how the bike runs,I,m happy with it.

Really great videos! appreciate them, and it looks like you've got quite the riding area too. Thank you! IT looks like your bike runs like a beast with the 165 kit on it.

has anyone tested the wb165 on a mx track against a 250f ? or would the 144 be a better choice for mx? i still say same rider on a 250f vs the 144 the 250f would win, i might be wrong though

Max Power turned my 60mm CR125 (167) cylinder into a $1500 doorstop and never made good on it. Botched the cylinder repair and stripped it too many times so it couldn't accept enough plating to get proper bore clearance. All they said was "sorry". I know the basics of their builds are good as Rick Peterson developed them and they simply bought the rights to his work. But they sure did me wrong. For that alone I'd put more faith in Walt's wb165.

Walt I'd like to talk to you about stroking these motors and rod length as you seem to be the man with these.

I haveposted many a race video showing how well the walt smith 165 works Plus in over 1000 miles it has
never let me down