Skip to content
View in the app

A better way to browse. Learn more.

Trials Central

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

My 4rt

Featured Replies

Panerai,

Fabulous Pics, I think it is great you are able to do all that engine work yourself.

Hope the bike is performing as you had hoped.

Baldilocks Posted Today, 06:33 PM

is this GasGasBens Uncle ?

:rotfl:

Ok ok, at first : i draw and make (with a friend) all the bolt ! not buy in a dealer. my engine power up kit have 270cc (bore is 80.00) piston "J.E" for CRF + cam shaft HRC + body throtle "two" mape + Termignoni exhaust titane. The resultat is : bof !!!! the "RPM" elevation is "slow", the torque is better, the power is better to, but news vibrations (not big, but........) because the piston is more heavy, it is not for a 4RT..... well, this is my sensation.

Franck.

How much did you mill off your 270cc piston? Is it to the same height as the standard piston?

  • Author

Hi, i cut the "wings" of the piston and the height is ~~ same... but it's not enough ! the top of the piston is cut to (for correct the compression ratio) all the kit for 4RT use a CRF'piston kit, never "special" for 4RT (except the HRC'260 kit, but the difference is just 1.5 mm bore) it's easy to see, the top of the piston have the valves' print and the valves of the CRF is bigger than 4RT.

Franck.

Ps: have you see "Forumty" ?? and what do you thinks ??

  • Author

You have in "Trials Central" a very great guys !! he a make himself lot of beautiful things (for 4RT and many other bikes) his name is "fantic303". In England it's fantic303 in French it's cotafan ! hello Bas !!

Franck.

thank you Franck, but you have also made a lot of nice things ! modification of the chain tensioner, your fuelpump bracket, pressure regulator etc, etc....

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.