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View Full Version : 04' Suzuki Z400/Kawi KFX400 Frame Cracks



wrewster
03-02-2004, 09:55 AM
Does anyone out there own an 04' Suzuki Z400/ Kawi KFX400 and have the noted upper shock mount stress cracks in there frame just like the 03's did? I am just curious. I had one of the original batch 03's and experienced no problems whatsoever with my frame but I didn't jump it all that much. I sold it and I am going to buy the new 04' and I called Suzuki customer relations and they say the problem was taken care of. I also spoke with John Arens who makes frame support brackets to fix the problem and he says I still need his bracket for the 04' models and that nothing was changed between either of these model years. I just wondered if the problem is still widespread like the early 03' models???

4TraxRider
03-02-2004, 10:03 AM
I've got an 03 Z and it cracked in multiple places. I was riding with an 04' KFX the other day and he's had it for a month or so, and the paint was chipping at the front shock mounts, but it wasn't cracked. I heard they took precautions to help it but I'm not too sure it was very successful.

jarsong
03-04-2004, 07:14 AM
Originally posted by wrewster
Does anyone out there own an 04' Suzuki Z400/ Kawi KFX400 and have the noted upper shock mount stress cracks in there frame just like the 03's did? I am just curious. I had one of the original batch 03's and experienced no problems whatsoever with my frame but I didn't jump it all that much. I sold it and I am going to buy the new 04' and I called Suzuki customer relations and they say the problem was taken care of. I also spoke with John Arens who makes frame support brackets to fix the problem and he says I still need his bracket for the 04' models and that nothing was changed between either of these model years. I just wondered if the problem is still widespread like the early 03' models???

From my research It appears to have been a rolling line fix that occured Dec02 / Jan03 or there about... You'll have a tough time finding a chronic broken frame problem on any Z400 sold after say March of 03. I have compaired my "Sept. 03" frame with the 04's and they are the same. Doesn't mean they won't break but it's no more likely than any other bike being put through the same abuse. My late 03 has ZERO frame problems and it's been put through the ringer a few times....
jarsong

wrewster
03-04-2004, 09:15 AM
Originally posted by jarsong
From my research It appears to have been a rolling line fix that occured Dec02 / Jan03 or there about... You'll have a tough time finding a chronic broken frame problem on any Z400 sold after say March of 03. I have compaired my "Sept. 03" frame with the 04's and they are the same. Doesn't mean they won't break but it's no more likely than any other bike being put through the same abuse. My late 03 has ZERO frame problems and it's been put through the ringer a few times....
jarsong

**Thanks Jarsong, that's the input I am looking for. I owned the first release 03' Z400 and didn't have any paint flaking off the frame or stress cracks and figured it was only occuring on machines that were jumped quite hard. I jumped mine several feet 6 or 7 feet high and 15 to 20 feet distance with no problems whatsoever, but my friend ( who bought his at the same time) jumped a little further and higher than myself and he did get some paint flakes and cracks in his frame. I have been having a dialogue with John Arens about this and as an extra precaution I am going to get his frame brace. He says that they are extremely pleased to report no problems since this has been tested. I treat this no different than saying that all stock skid plates aren't strong enough for my needs so I buy an aftermarket one because it is stronger than stock and ios an easy bolt on. No different than just buying this brace to add strength to the frame if you ever question about jumping. It annoys me when people are too quick to call something junk just because they are relentless about abusing there machines way past what they are supposed to be doing. I do wish the companies would offer a full on race machine that leaves no room for the aftermarket to improve anywhere but I know it would be big dollars.

wrewster
03-04-2004, 09:50 AM
Here is some interesting reading for all of you to check out on the Z400 frame fix;

Suzuki and Kawasaki teamed up last year to turn the sport ATV industry upside down. Basing their machines design on the ever-popular 400ex frame, which is known to highly resemble one of the best geometries designed to date, the 250R. Not unlike most first year quads however the LTZ400 and the KFX400 had some minor growing pains. Approximately 90% of the Suzuki frame is machine welded, meaning that a computer controlled welding arm has done the welding. These are easy to spot, as they are a very smooth and consistent bead. However a few select items on the frame were welded by hand. Although these are not all together bad welds their inconsistency makes for stress risers.
After approximately 6 months of release the first couple signs of a frame problem began to surface, initially ruled out as minor defects/flaws or constant abuse. However after several more months the cracking problem grew at an undeniable rate. At one point we were seeing a new crack, break or bend pop up every other day on the forum scene.

The cracks are generally focused around the front upper shock mount right where the channel mounts to the frame, as seen in the pictures above. The break usually starts with a small rusting crack and proceeds to grow until either the tube gives or the weld breaks. Until now the only choices that you had were to wait for the break to happen and pray that your dealer would try and get it replaced under warrantee, or strip the machine down and have it gusseted before the problem ever begins. Thanks to the people at Arens Brothers Inc., namely John Arens there is something you can do ahead of time to try and stop the inevitable.

Arens saw the problems forming with the frame and decided to attack the largest problem directly. Around March of 2003 they developed an upper shock brace that is designed to distribute the loads placed on the channel and welds back to the surrounding tubing and distribute uneven loads placed on one shock to both. The brace, although fairly simple in concept, has some solid engineering basics supporting it. I will warn you however, the brace is not designed to fix broken frames nor will the cracks that have already began to form stop just from installing this brace. If you are simply looking for an easy to install solution to your worries of a cracked frame then this is the way to go.

John is a notorious stickler for details. His initial release of the brace was stifled by redesigns and alterations in an attempt to fit every LTZ and KFX produced. The frames front upper shock mounts have a tolerance zone that makes this task nearly impossible. But after installing the brace myself I must say that the Arens Bros. have done their homework. The brace not only installed in about 15 minutes but also required absolutely no alterations on my part. Zinc plating on all the components is an unexpected bonus as I feel paint or powder coating would chip or fleck off after initial installation exposing bare metal and inducing rust. I also felt that using the existing hole in the frame plate was a nice touch. Not causing any alterations to the frame and forcing you to install the brace correctly. Arens has also informed me that the currect tubular brace design is under a slight redesign. They are raising the tube another 1/8" and eliminating the 1/8" spacer, there by simplifying the installation even more.


**Now for the bottom line, you want to race MX and you want to know if this is the fix all save all solution. My answer to you would be NO. Racing is a whole different situation and I would say if you are serious to purchase yourself an aftermarket frame or at a minimum gusset your frame. Now for the weekend warriors and after work/school small to medium jumping riders, I would say this is the best route to keep your machine up and running with little to no interruption.**






_________________

jarsong
03-04-2004, 10:02 AM
Originally posted by wrewster
**Thanks Jarsong, that's the input I am looking for. I owned the first release 03' Z400 and didn't have any paint flaking off the frame or stress cracks and figured it was only occuring on machines that were jumped quite hard. I jumped mine several feet 6 or 7 feet high and 15 to 20 feet distance with no problems whatsoever, but my friend ( who bought his at the same time) jumped a little further and higher than myself and he did get some paint flakes and cracks in his frame. I have been having a dialogue with John Arens about this and as an extra precaution I am going to get his frame brace. He says that they are extremely pleased to report no problems since this has been tested. I treat this no different than saying that all stock skid plates aren't strong enough for my needs so I buy an aftermarket one because it is stronger than stock and ios an easy bolt on. No different than just buying this brace to add strength to the frame if you ever question about jumping. It annoys me when people are too quick to call something junk just because they are relentless about abusing there machines way past what they are supposed to be doing. I do wish the companies would offer a full on race machine that leaves no room for the aftermarket to improve anywhere but I know it would be big dollars.

I actually think it has more to do with the front shocks than the frame. I updated mine to the WORKS with Rezzies, way better now....
jarsong

86atc250r
03-04-2004, 10:49 AM
The problem can be attributed to a few things. First being that the factory shocks are not the greatest and allow the quad to bottom easily. This transfers the bulk of the stress to the upper shock mount.

This will also happen with aftermarket shocks, but it will take longer since they are less likely to bottom out violently.

The only real way to fix it is to strengthen the area and/or disperse the force over a larger area. From what I've seen of the Suzuki frames, they have not addressed the problems.

The rest of the LTZ's problem also lies in the frame construction. One very large problem area is just behind the rear lower control arm mount.

If you look at a Honda you will find this area heavily boxed in. If you look at a YFZ, you will also find this area has a box/tray section built in. On the LTZ this area is completely open and not supported in any way --- not only that, but you'll find where the tubes come together to create a natural pivot point for things to bend if they receive stress (like from hitting a tree with a front tire). On the Hondas and Yamahas you'll find that these are continuous tube which is stronger than the Suzuki design.

In my opinion, the LTZ chassis, while geometry is good - has some very serious design flaws that affect it's integrity that still need to be addressed from what I've seen.

In my experience having numerous friends that race LTZs - I have seen problems ranging from broken subframe mounts, to broken upper shock mounts, to front ends being knocked over several inches (from very mild hits), to other numerous cracks. If you have or want an LTZ, one of the first things you should do is buy a gusset kit as insurance.

jarsong
03-04-2004, 11:04 AM
Originally posted by 86atc250r
The problem can be attributed to a few things. First being that the factory shocks are not the greatest and allow the quad to bottom easily. This transfers the bulk of the stress to the upper shock mount.

This will also happen with aftermarket shocks, but it will take longer since they are less likely to bottom out violently.

The only real way to fix it is to strengthen the area and/or disperse the force over a larger area. From what I've seen of the Suzuki frames, they have not addressed the problems.

The rest of the LTZ's problem also lies in the frame construction. One very large problem area is just behind the rear lower control arm mount.

If you look at a Honda you will find this area heavily boxed in. If you look at a YFZ, you will also find this area has a box/tray section built in. On the LTZ this area is completely open and not supported in any way --- not only that, but you'll find where the tubes come together to create a natural pivot point for things to bend if they receive stress (like from hitting a tree with a front tire). On the Hondas and Yamahas you'll find that these are continuous tube which is stronger than the Suzuki design.

In my opinion, the LTZ chassis, while geometry is good - has some very serious design flaws that affect it's integrity that still need to be addressed from what I've seen.

In my experience having numerous friends that race LTZs - I have seen problems ranging from broken subframe mounts, to broken upper shock mounts, to front ends being knocked over several inches (from very mild hits), to other numerous cracks. If you have or want an LTZ, one of the first things you should do is buy a gusset kit as insurance.

First off if you race all bets are off, don't care what you ride. Second where are the examples of non racing bikes braking frames with March 03 and new bikes? I posted this very same thing on the actual z400 web site, had over 500 views, ZERO broken bikes that weren't from flogged machines.... SOme things die hard...
jarsong

86atc250r
03-04-2004, 11:13 AM
Easy there. Just trying to provide help - no need to get all touchy.


In racing you can easily and directly compare how two quads will hold up, because they're both being pushed thru the same conditions - racers also tend to talk freely about thier quads and discuss problems they've had so they can try to get them solved.

Also most of my racing experience comes from a cross country environment - which is nothing more than an aggressive trail ride. I'm not talking about national level racers - most of my guys are local boys that trail ride far more than they race.

Secondly, one of my friends who's frame was practically totalled is a very non-aggressive trailrider who's never raced before in his life. He bumped off a tree while in 2nd gear - not even hard enough to extract him from the quad.

Check the areas I mentioned, and try being less touchy & you may learn something that will help you some day.

Pappy
03-04-2004, 11:17 AM
like it or not....the z400 if not attended to will crack up. ive seen 14 year old non aggressive riders with cracked frames. it is a design flaw period. and gabe is correct.....the z400 front area is really really weak.

jarsong
03-04-2004, 11:30 AM
Originally posted by 86atc250r
Easy there. Just trying to provide help - no need to get all touchy.


In racing you can easily and directly compare how two quads will hold up, because they're both being pushed thru the same conditions - racers also tend to talk freely about thier quads and discuss problems they've had so they can try to get them solved.

Also most of my racing experience comes from a cross country environment - which is nothing more than an aggressive trail ride. I'm not talking about national level racers - most of my guys are local boys that trail ride far more than they race.

Secondly, one of my friends who's frame was practically totalled is a very non-aggressive trailrider who's never raced before in his life. He bumped off a tree while in 2nd gear - not even hard enough to extract him from the quad.

Check the areas I mentioned, and try being less touchy & you may learn something that will help you some day.

Nah, no harm done. Just think the Z400 is still taking a needless hit on there frames on the late model bikes. The real problem is Suzuki hasn't been as up from with what they did to fix the issue leaving lots of room for the rumor mongers to get going..... jarsong

jarsong
03-04-2004, 11:35 AM
Originally posted by Pappy
like it or not....the z400 if not attended to will crack up. ive seen 14 year old non aggressive riders with cracked frames. it is a design flaw period. and gabe is correct.....the z400 front area is really really weak.

Understand what you are saying, buuuut, were still waiting for all those broken frames to show up on bikes produced after March of 2003????
Telling you, I've polled this on the Z400 site and had no takers other that from someone who either wrecked there quad of flogged the hell out of it. Even then there was I think one or two. Also one person had a frame replacement that broke but surely it was from earlier stock... If you race you quad, you should gusset it, doesn't matter what name is on the plastic....
jarsong

86atc250r
03-04-2004, 12:06 PM
Check the areas mentioned - if they haven't changed, the problem still exists.

Pappy
03-04-2004, 12:22 PM
lol...poll or not, i have personally seen 3 week old quads cracked. i yell at harlen everday about his z400's and if you search the non honda section, i predicted the areas that would be problematic before most folks even purchased a z;)


ive powdercoated 2004 z400 frames along with several 03 frames and i havent noticed any areas improved

popo
03-04-2004, 12:34 PM
I broke three frames, and I am slow. Bought an LRD Alum to solve the problem.

jarsong
03-04-2004, 12:42 PM
Originally posted by Pappy
lol...poll or not, i have personally seen 3 week old quads cracked. i yell at harlen everday about his z400's and if you search the non honda section, i predicted the areas that would be problematic before most folks even purchased a z;)


ive powdercoated 2004 z400 frames along with several 03 frames and i havent noticed any areas improved

From looking at the first gen frames against mine, the "Quality" of the welds appears to be the only difference.
jarsong

jarsong
03-04-2004, 12:58 PM
Originally posted by popo
I broke three frames, and I am slow. Bought an LRD Alum to solve the problem.

Looks like your a racer from your sig.
jarsong

wrewster
03-04-2004, 11:15 PM
Originally posted by Pappy
like it or not....the z400 if not attended to will crack up. ive seen 14 year old non aggressive riders with cracked frames. it is a design flaw period. and gabe is correct.....the z400 front area is really really weak.

Then just strengthen it with an Arens frame brace and it should be just fine and strong enough for most people. According to John under his testing it has proved to rectify the problem.