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TurboDon

Time to split the cases on the ole wr400. Worthwhile upgrade recommendations needed.

7 posts in this topic

Well I'm pretty certain the rod & rodbearing finally exceeded their wear limit last weekend on my 99 WR 400.

 

The bike has a lot of hours/ miles on it. I want to freshen it up, make some good upgrades and get it ready for another decade or so of abuse.

 

As it sits the bike's current mods engine wise are : grey wire, yz timed, dr.d pipe, and airbox mods, and that's basically it.

 

The power on this bike has always been ok and it has been a solid runner. starts first kick unchoked stone cold and will go right to idle.

 

So basically I'm wondering what upgrades are recommended to be done while I have this thing torn down.

 

Here's what I had in mind.

 

have a new 426 rod pressed on the crank.

 

bore cylinder to 95mm.

 

13.5:1 weisco 426cc piston.

 

freshen up the head, most likely do some porting or at least port clean up (myself).

 

was thinking of upgrading the carb to something off a newer 426 or 450 (thoughts on this?)

 

should I change any bearings out?

 

should the clutch be upgraded for the increased power?

 

any other tips/ tricks/ suggestions?

 

Thanks.

 

-Donald

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Personally, I'd not invest the money and time in it and I'd get a later model for the better handling

Even if you replace every bearing and worn out part you are still gonna have a 15 year old bike with handling of a bike from the nineties

the al frame bikes were a good step forward in term of hanlding, over the steel framed 400/426/450 bikes

 

If you really do want to keep then replace rod, main bearings, any of the gears with pitting on the faces of the teeth, piston, rings & valve seals.

Sorry can't advise on the specifics, as I'm not that familiar with the 400/426 variants

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Ya I want to keep it for sure.

 

The 6 hundred dollars or so for an overhaul is a small price to pay compared to scrapping it and buying a new bike.

 

Being as its plated in California makes it a pretty desirable.

 

I'm a pretty experienced rider and am not ashamed to say I've been passed hard by older vets on XR400s out on the trails.

 

A newer bike isn't going to make me get from point A to B any faster..... That electric start would sure be nice tho!

 

Thanks!

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I actually have had 2 1999 wr400s. I love them. I still have one.

Have you heard of filing down the throttle stop?

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I actually have had 2 1999 wr400s. I love them. I still have one.

Have you heard of filing down the throttle stop?

 

Yeah I've heard of that one, For some reason when I checked mine out it seemed as though the slide opened to it's full potential without any modifications.

 

When I do this overhaul I have been contemplating putting on a newer carb off a YZ anyhow.

Edited by TurboDon

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Good to change the rod, iv seen a heap of wr 426 end up getting scraped after the rod failed, iv got one and they keep coming up on eBay in aus!

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