WR400F radiator widths

Hi guys!

I just wanted to ask a quick question.

I recently purchased a new no-brand aftermarket radiator off of ebay for my old 2000 model WR400F that's been sitting in the shed being unused for the last couple of years (I upgraded to a new 2010 YZ450F a little while back). Anyway the original radiator on the bike was bent downwards on one side, so I decided to replace the whole thing since I've been cleaning the whole bike up and making her look and run like new again. Might I add, it's looking great now!

Anyway my problem here is that the new radiator panels I purchased (The fins that protect the front of the radiator) are too wide for the new radiator I now have on my bike. All the holes line up fine to fit the new panels, but the panels themselves are about half an inch too wide making them impossible to slot into the predrilled holes of the radiator. The panels I purchased are OEM and were designed for the 2000 model WR400F. The part number for each of them is "5BF-2172A-10-00".

Since I have the OEM radiator panels for my bike, I'm assuming the radiator I've purchased is actually designed for either the 98 or 99 WR/YZ400's and not for the 2000 model. I don't know this for sure, that's why I'm putting the question to the knowledgeable folk of TT! I don't want to buy the wrong panels again since I had to source them from the US and wait 3 weeks to get them here in Australia.

I've looked up the part numbers for the 98 and 99 model WR400F's radiator panels, and for both years they have the number "5BF-2172A-00-00". This is almost identical to the ones I purchased, but the 2000 model has a 1 for the 9th digit. The actual OEM radiator part numbers have a similar setup with only the 9th digit differing between the 98/99 models and the 2000 model. The microfiche picture for all three years shows identical panels, so I'm almost certain the 9th digit being different is merely because the radiator was slightly wider on the 2000 model.

Just to be sure I order the correct panels this time, is somebody able to verify this by letting me know the internal width (where the radiator panels go) of their radiators on their 98 or 99 model WR400F? I measured the internal width of each one of my radiator halves to be 107mm.

On another note, does anyone know if the YZ radiator panels differ in any way either? The part numbers for both 98 and 99 YZ400F's are "4EW-2172A-10-00", which is exactly the same as what I purchased but begins with "4EW" instead of "5BF".

For something so simple it's been driving me mad! I can't ride the old girl until I have the panels, so I'm hoping to get the right ones ASAP! I'm not even able to check against my old radiator because it was originally off of a YZ426 and had the diagonal mounts for the shrouds on the outter edge of the radiator.

Thanks a bunch for any help,


Edited by falkz89

It's probably your radiator that's the problem. I've never had any luck getting the roost guards to fit aftermarket radiators. So instead, I just use some radiator guards instead of the flimsy roost guards. Hope this helps!


Thanks for the reply Maniac. But I actually did a bit of research on Yamaha part numbers themselves, and I ended up coming across this:

"Design Code Number Data: XX0-X000X-X0-X0

The ninth and tenth digits of the part number indicates differences, corrections or modifications to the original part number. The ninth digit position (000-00000-X0-00) may be substituted with a letter. This position indicates variations thet may exist within a specific item, i.e.

1J7-12169-A1-00 – Pad Adjust 1J7-12169-E1-00 – Pad Adjust 1J7-12169-F1-00 – Pad Adjust

The tenth digit of the part number (000-00000-0X-00) indicates the number of times the design of the part has been changed."

Judging from what I've read there, I'm assuming this to be the reason why my panels are in fact slightly wider than the radiator itself and that the 98/99 model panels will be the correct size to fit my radiator. Since I plan on selling the old girl before long, The OEM panels should do me well for now. I'll order a new pair of panels now and let you know how I go!


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