test rode a WR400 today: why no bottom end?
Posted October 23, 2007 - 05:23 PM
I was suprised to find that while it runs very clean down low, It had a hard time pulling in the low and mid range: it really needed to rev out to pull each gear. And it was geared very low (55mph tops).
I suspect a worn piston/rings, as it had no decelleration resistance when the throttle was backed off (unlike my Honda CRF).
Is this basically the nature of the 400: a bit revy, and about 36 hp? That's what it felt like (compared to my uncorked DRZ 400).
I'm asking because I like the way the WR's handle the really tight trails, and there are several plated ones around here to look at.
Posted October 23, 2007 - 10:08 PM
Posted October 24, 2007 - 04:06 AM
Were oyu able to kick it without using the decomp. lever to get you past TDC for the kick - I'd expect that to be a sign of lower than normal compression.
Posted October 24, 2007 - 07:56 AM
Posted October 24, 2007 - 09:35 AM
I'm sure you can do it yourself!
Posted October 24, 2007 - 09:40 AM
My dad's WR426 is an animal. It is a little heavy but it definatly is no slouch. It flat gets up and goes!
Ride a different WR400 and feel the difference!
Posted October 24, 2007 - 12:49 PM
Posted October 24, 2007 - 02:09 PM
Definately something wrong with that bike...like you suspect, probably top end. Was it hard to start? Could you kick it through wihtout the decomp lever? If the valve train had been gone through, it's possible that the intake cam is timed wrong, as well. Will the owner let you run a compression check? My 444 puts out about 185 psi. I would expect a 400 in good shape will be somewhere between 165 and 180 psi as well. If the compresion is good, offer the guy a bit less, and work the issue. Maybe cam timing, maybe ignition. As you know, the plate is worth a bunch and you will love the bike once you get the low end worked out. I'm in Palmton and have a 426...available for parts swapping shotgun troubleshooting if you pick the sucker up.
Posted October 27, 2007 - 09:02 PM
The WR/YZ400 is the benchmark for all bikes since it's introduction. If your bike performs the way you say it does, something is wrong for sure. The only problem with the 400 IMHO is it's weight, the newer bikes are lighter especially the KTM's but I can't afford them.