KTM450 - Fork Seals keep Blowing

[cloverdale]

I have a 03 KTM450EXC and continue to routinely blow the fork seals. I have owned/raced enduro bikes since the mid 70's with out ever having this problem with a bike. The seals are kept clean,etc. I took apart the forks and noticed the three bushings seemed loose on the main fork tube. I purchased new ones but there still seems to be a lot of slop @ the fork junctions. Any help would be appreciated!

 

[John Curea]

cloverdale

The 03 KTM fork seals have caused alot of concern and anguish, especiallyfor the off-road crowd. Last year was so muddy at the GNCC races, riders were having a hard time getting 3 or 4 races before leakage. The 03 KTM seals arent as good as they should be, and this is where basic bike maintenance is gospel. Try and keep the lower tubes clean in between rides or practice sessions, even wiping the dried water stains after washing helps alot.

Enough preaching....

You have a couple choices, use the 02 SX fork seal, this is the blue seal made in Germany, or use 48mm KYB seals. 48mm KYB (04 YZ, or 02 and newer KXs) are a bit tight to install in the upper tube, but this can be accomplished with a good quality seal driver. Caution: dont try to install these without a seal driver. Another plus is that they have 2 spring bands to help with sealing.

If you want minimul stiction and dont mind the constant upkeep, go with the blue 02 SX seals, if you done mind a very minimal amount of excess stiction and desire the prolonged seal life, go with the 48mm KYBs.

Take Care, John

 

[DEANSFASTWAY]

Howsit John? Sometimes I have a tough time with those seals on the 48s and the WPs double bushings also . The whole thing seems to go a bit better if you warm up the upper tube a bit.The first couple times I used the KYB seals (on WP)I shaved down the lower outer extrusion on the seal to help start the seal, now I just heat the tube, it helps with starting the thin upper bushing also . I was wondering a bit how the triple bushing setup could be losing seals so easily with 2 upper bushings for the oil to get past, maybe theyre actually trapping the oil.When they first came out I saw a set of modded forks with slots cut in the top upper bushing , i dont think it was effective for anything other than bleeding maybe.Usually its just dirt fouling the seals up. I also wondered why the KTM seals need to cost 24 bucks each whether theyre blue or black. Husky seals too come to think of it.