EC250 Fork Swap (Marzocchi 45 to WP 43)
 

My Marzocchi 45mm forks on my 2004 EC250 are shot and I need a replacement. I found a set of WP 43mm forks from an earlier EC (not sure what year or displacement). The number on the top of the WP fork tube is 0550w709. These WPs come with the Triple Tree and the axle. Will the WP just bolt onto my 2004 EC frame? Is the front caliper compatible between the WP43 and the MZ45? Anybody done this? Thanks.

I would see no reason why not. I converted from 45 Zokes non USD to 43mm USD WP's. Direct swap from a 03 EC300 onto a 99 EC200. I bought complete end with axle and brakes.
I would assume that the new front end has a Nissin caliper, as your old front end had Nissin caliper as well. The only difference may be in the axle size, and so different spacers, bearings, and bushing may need to be used. All of those parts can be had from a GasGas dealer.

My WP forks are WP4357's.

Good Luck

Make sure they aren't KTM WP's, as there are slight (but important) differences in the bottom fittings. The caliper will bolt to either fork lower, but the lugs are thicker on the KTM base and move the caliper inboard, causing the caliper to ride against the rotor. Also, the axle wrench end (right side, with the hex) is smaller on the KTM version than the GasGas. This is comparing a set of 2002 GG 43mm USD WP's with a set of 2001 KTM 43mm USD WP's. I am at work tonight, but I can look at the foirks tomorrow and get you some part numbers, if you want.

Thanks for your help. I can't seem to find any info online about that WP model number (0550w709). I have heard that the earlier WP43 forks on GasGases (2000 or 1999?) were set up for brembo calipers and my 2004 EC has nissins. I don't know exactly what year bike the WP43 forks are coming off of, but it doesn't come with a caliper, so that's a concern. From another angle, I also found a set of forks off a 2003 FSE400, but I'm waiting to find out which ones they are (WP, MZ, or Ohlins). Have you had any experience with the Ohlin 43mm that GasGas used? I like the idea of using the WP because parts are so easy to find. Maybe Ohlins would also be a better choice.

The GG came with WP forks and nissin brakes, so if it's from a GG the caliper will fit.
Gmp is right about the ktm fork, they use different caliper and axle, but both forks fit into your stock triple clamp, the 43WP & 45Zokes have same clamping diameter, length and travel, so it's a easy swap.

WP usd
 

I have a front end off of a 2002 gas gas mc125 part # 050w707 45:01 that I want to fit to my ec250 I think they are WP`S but they meassure 43mm and on the top of the forks its got 45:01
Will this be do able?