4HW max RPM

[SpookDog]

Any owners please let me know what the max RPM is when riding. I'm trying to work out the best size carb to fit

CC x maxRPM divided by 3.456 to give the ideal Cubic Foot rating.

Also, what the standard barrel is on a 4HW? I have a 3MB~P to go on mine, though I read somewhere that a 4FU is fitted to some with a 32mm Delortto?!...

Any and all help is much appreciated 😜

[SeaR1ck]

My tzm 150 with it's lame mikuni VM 30mm carb tends to hit a wall at 10.5k

The 4dl with that cylinder had the 32mm dellorto. I've been thinking about putting a bigger carb on mine. Think it might help it up top with more rev's. Been looking at the vm 34mm just because I'd like to keep the airbox. It's funny how the 28 / 30mm has the same body dimensions as the 34mm. But the 32mm is different.

I wouldn't put a dellorto on it they are okay.
If I was going to drop coin on the ultimate setup.

It be a keihin pwk air striker/quad vent 35mm. The keihin is easier to jet and less bothered by temp changes vs mikuni.

On the dirt bike side of things I've been seeing a lot of positive things about the Stic metering bloc for the pwk's. Like increased power throughout with massive increases in torque and over rev.

I'd really like to try one first they aren't cheap though like $350 400 usd. Some negative feedback is it's to much and you really need to put a slower turning throttle tube in. Guys were hitting like max power with only quarter turn of the throttle.

https://youtu.be/Bv17qRAL1pI?si=nKYwe7xtrqnzGSV1

[Chris_]

Hi,

the oem standard barrel for the 125 cc TZR HX (FL in german) is the 4FU Cylinder with flat-top piston and special cylinder-head. It is possible to mount a Belgarda 3mboo kit (P stands for ported in Italy) but then you have to install a Dome-Piston (convex) and the right cylinder head ! Dont mix the parts.

On a Hx normally there is a 28 Mikuni mounted, on a DL there was installed a Dellorto 32 VHSA.

On my DL i can rev till 12 000 rpm´s ( with a jollymoto, peak at 11.500 rpms). With original LaFranconi exhaust normally the peak is 10 500 and you can rev till 11.000 rpms.
I never have ridden a hx but i can remember that the HX/FL rev 1000rpms more than the Dl´s. You can see it at the speedo, the rpm-red-line begins at 11k for the DL´s and  at the HX/FL speedo  the redline begins at 12 000....

Cheers