07 250r Revival

[Loganclark73]

Hey guys, I picked up an 07 250r a couple weeks ago and I'm looking to get back into track riding and local racing. The bike is low hours and hardly ridden by the two previous owners. Front tire still dates back to 07 even. Looking for any advice on model specific things to consider while I get this thing track ready aside from general maintenance. Thanks everyone

[mlatour]

Inner ICS piston seals and lower cartridge/rod seals are some weak spots of the Showa TC47 forks.

 

Both bikes from that era / design that I've service needed those seals replaced,

as the cartridges sucked in air and damping was mushy.

 

Check the valve clearance and note the sizes of the shims used, 

that might give an indication if they've been shimmed considerably.

 

Any past head/valve/timing chain & tensioner /piston maintenance history ?

Depending how hard you'll push this engine when racing it's a consideration knowing what is the condition of things before hand.

Edited August 14, 2017 by mlatour

[Loganclark73]

From what I can tell the engine has been untouched other than oil changes. No witness marks on anything. Fork seals are leaking some so I was planning on replacing those. Is there a specific brand of seals and bushings for the forks to avoid the internal leaks?

[mlatour]

For the internal ICS piston and cartridge seals, you'll have to purchase them thru a specialized suspension vendor.

I buy them thru Factory Connection. NOK brand seals are OEM and it's very much suggested you only use that brand to avoid problems.

 

There is a how-to video on YouTube on doing the lower cartridge seals, 

the piston seals are a bit tricky but a blind bearing puller is perhaps the easiest way to remove them.

 

For fork tube seals and bushings, there are a few aftermarket brands but again,

OEM parts are preferred if you don't want to re-do the job sooner than expected.

Edited August 14, 2017 by mlatour

[mlatour]

As you dis-assemble the fork, if

-the rebound rods don't extend on their own (not all the way but at least 3/4 out)

-the cartridge 'gurgles' excessively when you cycle the rod (cavitation)

-the rod gets 'sucked back in' a few inches when you pull it out all the way

 

those are signs the internal seals mentioned have likely gone bad.

Edited August 14, 2017 by mlatour

[Loganclark73]

Awesome information man I really appreciate it. I'll look over things and keep updating as I work my way through the bike. 

[Loganclark73]

Will I need to email factory connection to request the ICS piston and cartridge seals? I can't seem to find them anywhere. Or any seals under NOK. Needed or not I want to completely rebuild the forks while I'm in there to help maintain service intervals and such. 

[mlatour]

Yes you will need to contact them, 

copy/paste the following infos in your message:

 

2007 Honda CRF250R

Showa TC47 forks

-ICS piston inner seals

-lower cartridge/rod seals

(Genuine NOK / OEM seals required)

 

I've recently ordered from them and serviced both the bikes listed in my signature.

Cartridge/rod seals were easier to do on the CRF / Showa forks,

ICS piston seals were easier to do on the YZ / Kayaba forks.

Edited August 15, 2017 by mlatour

[lakeportmike]

best mod I did to my 07crf (still have it) was to replace the oem titanium valves with aftermarket sst valves. The stock valves beat up the valve seats and require constant shimming...the sst valves seem to last forever.