Cracked case

[comander420]

So I looked on the back of the engine near between the sprocket and rear mount and there is a hairline crack. Has anyone else had this happen and what did you do to fix it, buy a new case or tig weld it?

[jjames/jlawson]

We have a motor for sale ???? Cheap......
Thanks
Jackie

[draygarcia]

how cheap is cheap

[ZX11]

I know the cases can be had online from OEM suppliers for $540. That gets you both sides. I didn't see just the right side listed. The problem is getting the 2010 versions which are not supposed to crack.

I checked around since I didn't get the long term warrantee for my 08. Post how you wind up fixing the problem.

[TNT]

Post a PIC of it I'll tell you how to fix it if you want. I just need to see the exact area not a real close up of the cracks.

[BCS Performance]

Well unfortunately this is a problem that the DS does have. There is a lot of flex in the chassis in the back down by the pivot area which causes a little stress in this area. There is a fix that is coming that will cure this problem right now. As for now what everyone in the New England area has been doing is putting a couple of layers of JB weld on the case. Now I know this sounds crazy and like a hack but believe me this will get you buy until the fix is available. We have been testing a couple of different things to cure the problem and have been quite successful. Now as far as JB weld goes you will be fine for as long as you own the machine with just that. Like I said this will get you by without hurting anything until the fix is available. You would not want to buy new cases and have the same exact thing happen.

If you are looking to buy cases though, we do have them in stock.

[blaster99]

mine cracked, I put some jb weld on it to just get me through a weekend... this was in august, and they case is fine. If you look at were its cracking, even if it does crack all the way through, the swing arm is going to stay on the quad, so the jb weld is really just preventing and oil leak.

[TNT]

Best way to fix this is shotpeening with a ball peen hammer lightly, after surface grinding the area. This is what you do for gouges in metal too to keep them from cracking. Anyone cares to know why if so read further.....

See hairline cracks occur from fatigue on the surface in tension (pulling apart). When you shotpeen a concave in the surface it goes into compression on the inside of the hole and tension internally, the compression instead of tension on the surface keeps the tension away that started the crack to begin with. The internal tension created by the shot peen deep in the part is not a problem since cracks don’t start internally. The grinding for deeper cracks will cold work the metal and strengthen it prior to shotpeening. .

Sorry JB weld won’t cut the mustard! :D

[comander420]

would tig welding it work? Welds are stronger than the base material.

[TNT]

Originally posted by comander420
would tig welding it work? Welds are stronger than the base material.

Stronger only at the weld but you put a heat cycle around the weld that weakens the base metal. Again, shot peen the weld and surrounding area to relieve internal stress and your good to go!

[ZX11]

So there is a lot of flex in a pyramid aluminum frame? haha. I guess the intro videos from can-am were off base.

does the JB weld help the area before it cracks? Mine hasn't cracked yet but the postings are indicating that it will.

I thought the 2010 cases were the solution. But now it sounds like they will crack also.

[comander420]

look real hard, mine just looked like a casting mark but when I look real close I can see it is a crack. Mine cracked with less than 8 hours on the quad.

TNT when you say peen with a hammer are you saying just tap the area with a ball peen hammer and cold work it? I'm just afraid to knock a hole in the case.

This winter I think I might just have a buddy lay some welds around that area

[TNT]

JB weld will do absolutely nothing in the case of bonding surface cracks due to high levels of surface tension. Might make it worse.

ZX11 - The pyramid extruded AL cross section is very strong compared to castings and weldments other quads use; doubt you see many cracks in those areas that’s not the issue. All frames flex according to the Modulus of Elasticity of the metals used. It’s VERY difficult determining the overall load case on the quad, often times when you place a strong section in the frame assy it can cause problems in other locations. As much time as is spent determining loads from test data, stress-strain gages and computerized NASTRAN models, still the loads that were used in the model will need to be developed further from all the field testing and different riders/tracks.

To do this thoroughly, you might wonder, would require hiring 100’s of different riders putting them on 100’s of different tracts to get the loads model you design to correct. As you might guess the cost to do that in pre-design would be too great to the end user so you release the design to the public as most quad frames are, and let the after-market industry handle it which BCS is and has, incorporate the squawks at the next OEM design change…it’s done in automotive, aircraft(to a less degree), most industries. Not everyone will experience the issue, just depends again on many factors. 2010 frame design we hope will address the load dump into the engine.

Commander - Don’t beat the thing to death lol; all you want is some minor surface indentations. Yes! To cold work and put the surface in compression! A layer of JB weld once the cracks are closed and in compression might not hurt to hold down the tension, flatten it out and make it look nicer cosmetically.


:D

[blaster99]

Originally posted by TNT
[B]JB weld will do absolutely nothing in the case of bonding surface cracks due to high levels of surface tension. Might make it worse.



If you read my post, I said the reason for JB weld was not to keep the cases together, it was to stop the oil leak caused by the crack.

[TNT]

Originally posted by blaster99
If you read my post, I said the reason for JB weld was not to keep the cases together, it was to stop the oil leak caused by the crack.

It won't last and one things for sure your cracks will grow, it cant take the pressure. You'd still be better off shot peening to close the gaps then put a layer of an epoxy based resin that takes compression better.

Theres some pretty strong aircraft grade sealants on the internet that do a much better job than JB weld at sealing if thats all your worried about. This stuff we use is incredible strong. I'll look at the spec when I get there later and post incase you all and BCS ever find a need. I just used a thin layer to bond in some shim that mated two big commercial aircraft barrels and it held up, about 10,000 psi. It's an air sealant too. Crazy glue I tell ya!

But yeah I will scarp any aircraft part that has a crack even a toilet paper holder, but can shot peen gouges just to give you an idea and I know this is not aircraft but a crack is crack once it starts it's not if but when it will open up all the way.

:D

[ZX11]

So yesterday my case was fine in that area. Today I have a crack in that area. It isn't leaking but I can't tell how far down it goes. It is only a month old so I will be taking it to the dealer for some new cases. I wonder if I should bother with the 5 hour oil change, haha?

Really?!! Can-am built this problem into their 08's and they still do not have engine cases available that won't crack?

[TNT]

Well I looked at the aircraft adhesive I was talking about above and it can only take 250 deg F. However the company is below we get it from and they have some high temp flexable adhesives that are good to 400 and can take 350 psi tension.

All I know is the P/S 890 we use is flexable, super strong, and is non-corrosive.

One could call this company which I think I will since we have some hair line cracks on a YAM leaking oil that are getting worse and see what they recommend.

http://corporateportal.ppg.com/NA/Aerospace/Sealants/Sealants_Products/

[Ex_Rider43]

Wait for the 2010 update kit you will have everything you need to keep going without any problems. it might be available right now i am not sure.

[X400EX]

2010 update kit? I guess new cases and what else?

Mine started leaking oil too..

[ZX11]

Yeah, tell us more about the kit.

I got to get this documented while I still have warrantee time left. I only have the standard 6 month warrantee with 5 months remaining. After getting it documented, I can wait for the kit as long as it doesn't leak oil or I can stop the leak with an epoxy.

BRP better get this right. I only bought this to tide me over until I can get a seadoo RXT 255hp next year. If I can't trust a 45hp rotax engine to stay together on land, I won't trust a 255hp supercharged rotax to stay together offshore. Hmm, turbo honda watercraft are cheap.

[Blizzard24]

Are the updated cases having the same issues?

My 08 had a crack in the case and Can Am replaced the cases w the 2010 cases saying they have seen problems w the 08 cases and revised them.

I just took a look at Can Ams parts list on theor website and the 08 cases have different model numbers than the 09 cases, 10' isnt listed yet.

08 Case part #- 420685081
09 Case part #- 420685086

is anyone w an 09 or 10 seeing cracked cases? Since mine was replaced, I have had no issues (knock on wood)

[kellymi]

I haven't had a chance to look at my 09 yet, and I wont be able to for a couple of weeks. All I know is that it isn't leaking oil. I really hope the 09 cases don't have the same problem.

[ZX11]

Originally posted by Blizzard24
Are the updated cases having the same issues?

My 08 had a crack in the case and Can Am replaced the cases w the 2010 cases saying they have seen problems w the 08 cases and revised them.

How can they say they are 2010 cases if the part number doesn't seperate them from 2009's? A revision to fix the problem sounds great.

Hopefully Kelly's DS450 was built late in the year. I figure the early builds would have not had time to update parts from 08 lessons before they were assembled.

I wonder if the aluminum rim repair guys can fix the old case after can-am gets me new cases. Do they keep the cracked ones?

[TNT]

2009 will be the same part # for 2010 if it fixed the prob, 2008 part number is the bad one. For 09 owners it will be the engine # M...... when the change took effect, Since there are no bullitins we have no way of knowing when this got implemented on the line. I guess look at a 08 vs your 09 in the area. There are or were two down the street maybe I'll go look tomorrow.

[TNT]

Cr## I forgot we got 08 cases on a 09 from when we blew a rod out the case. Thanks for the great news guys! :eek:

I'm going down to the dealer to see one tomorrow. :mad:

Just got the motor back together today too.......Nice!

Ill figure this out.....:grr:

[Blizzard24]

Terry, I am just going by what the dealer had told me, it was a while ago so they may have said 2009-2010 cases when they told me what Can Am had done to fix the problem.

[TNT]

Originally posted by kellymi
I haven't had a chance to look at my 09 yet, and I wont be able to for a couple of weeks. All I know is that it isn't leaking oil. I really hope the 09 cases don't have the same problem.

Might be a good idea for those that have not crack to build up the area with some JB weld or Permatex has a good one with good tensile thermal properties.

JB weld
Tensile Strength: 3960
Adhesion: 1800
Flex Strength: 7320
Tensile Lap Shear: 1040
Shrinkage: 0.0%
Resistant to: 500° F

Permatex: http://www.permatex.com/documents/tds/Automotive/26346.pdf Tensile 4250, to 500F

Both at Advance Auto. Shotpeen a little first.

[ds450xracer]

TNT can you explain to me what shot peening the area is, i have a crack on my case but it is not all the way through yet and i would like to keep it that way
thanks

[TNT]

Sure! you get a ball peen hammer you know the one with a round end on one side and LIGHTLY tap the area. What that does is closes the crack puts a dome on the surface in compression and you cold work the surface which makes it stronger.

Here I did a quick drawing of what your trying to accomplish. This is an exploded section view of the engine by the crack.

In tight coners you may need some other tool like an auto-body hammer or any mandrel with a small dome on it. Afterward put some JB or Permatex to keep it in compression and keep the crack from growing or starting we hope! :D

http://i280.photobucket.com/albums/kk191/Terrylport/ShotPeen.jpg

[ds450xracer]

ok that helps me out alot, thank you very much and hopefully it will keep me from having to buy new cases

[ZX11]

BRP has decided not to change my cases until they start leaking oil. The dealer sent them pictures. The crack is very minor now. It doesn't extend down below the swingarm pivot. I am ok with that and will ride it until it becomes a problem. My warrantee runs out in 4 months ( it was the standard 6 month) and I wanted it documented as happening at the 5 hour mark. Is it normal for them to wait until it leaks? It is not like the crack will fix or stablize itself.

Is there any upgrade parts I should add when when they do finally tear down the motor to fix the cases? What is the oil nozzle?

[Blizzard24]

Change out the shift pawls to the updated part numbers, clutch update it if hasnt been done but thats about it.

[TNT]

The oil squirter is #9. Some have been cracking it. Would be a good idea to epoxy it in with permatex engine or last I heard BCS was working on a better one. If it breaks your crank gears are gunna grind and you'll need a couple hundred just in parts maybe more.

http://i280.photobucket.com/albums/kk191/Terrylport/Nozzle.gif

[X400EX]

TNT, I'm gonna rebuild my DS this winter and check out my oil squirter. I wonder if you would have a few minutes to make a little "howto" on that... Just to make sure I do it the good way when I'll be there!

Also, if you know anything else good to verify... I'd appreciate a lot to know!

Thanks for your time.

John

[TNT]

I wasn't there when the builder did it but it's just a matter of using a metal bond adhesive like permatex engine, scuff the mating surfaces up with scotch brite clean w/rubbing alcohol build up around it a little and the mating surface with glue and you'll be good to go. Its what we do in aircraft when we "fay surface and edge seal" parts in place.

Here's the deal talk to motoworks they never see them fail think it has to do with mechanics hitting them. Talk to BCS they have seen a few. My put bond it to be safe if it fails big bucks! Theres really nothing that hits them, the piston skirt does not unless it's a long one maybe....Our big bore doesn't so maybe motoworks is right someone hit it cracked it.....

Only other thing Motoworks brougt to our attention is the cam lobe @ TDC timing needs to be checked.....you may give them more call I was not there to fully see how our builder did it.

Other than that I'm putting some permatex on that area that has been cracking by the sproket and swing arm bolt and doing some shot peening first just to be safe.

Hope that helps and sorry I did not respond sooner it's been a nerve racking day racing. :D

[X400EX]

Originally posted by TNT
I wasn't there when the builder did it but it's just a matter of using a metal bond adhesive like permatex engine, scuff the mating surfaces up with scotch brite clean w/rubbing alcohol build up around it a little and the mating surface with glue and you'll be good to go. Its what we do in aircraft when we "fay surface and edge seal" parts in place.

Here's the deal talk to motoworks they never see them fail think it has to do with mechanics hitting them. Talk to BCS they have seen a few. My put bond it to be safe if it fails big bucks! Theres really nothing that hits them, the piston skirt does not unless it's a long one maybe....Our big bore doesn't so maybe motoworks is right someone hit it cracked it.....

Only other thing Motoworks brougt to our attention is the cam lobe @ TDC timing needs to be checked.....you may give them more call I was not there to fully see how our builder did it.

Other than that I'm putting some permatex on that area that has been cracking by the sproket and swing arm bolt and doing some shot peening first just to be safe.

Hope that helps and sorry I did not respond sooner it's been a nerve racking day racing. :D

Thanks Terry, you're always a great help!

[joedirt]

I was "shot peening" the crack on a friends quad and a chunk of the case broke out. Anyone know a good welder?

[TNT]

Originally posted by joedirt
I was "shot peening" the crack on a friends quad and a chunk of the case broke out. Anyone know a good welder?

That was more than a surface crack. :rolleyes:

Like I said it's more for gouges. DON'T BEAT ON A DEEP CRACK! I said all your trying to do is put the SURFACE in compression do it LIGHTLY!

Hope you can weld that allright! Anyway you look at though like I said once the crack has started it's not if it's when it will open up. We scrap aircraft parts that are cracked...New cases are best! A weld may not hold either. Just a bad design!

[comander420]

That is what I was afraid of, the case breaking. I think I'll just start with the welding and see what that gets me.

[TNT]

We'll have to see if the 2010 cases fixed this, looked like to me from the photo the location was a high load area, how the new aluminum cases will take it is TBD.

Back to the crack if it looks like it's any more than .030 deep don't shot peen it just put some Devcon on it our engine builder says it super strong has been using it on engines and it's better than JB weld.

http://www.itw-devcon.co.uk/index.php?/devcon_mro/epoxy_adhesive_systems/devcon_2_ton_clear_epoxy/

He processes about 10 engines a day so I'll trust him and try it but we don't have a crack yet! Knock on wood.

[TNT]

Call JSR John Stallworth he's been building quad engines that past 25 years....I think he said Devcon is what he uses and it works great! He can get ya some too...316-733-1936

[TNT]

http://www.nolansupply.com/bysubcategory.asp?category=Fluids+and+Lubes&supercategory=Repair+Putties&subcategory=Devcon+Aluminum+%26+Plastic+Steel&type=False&specs=True

[TNT]

Heres the shot peening we use on aircraft for gouges and surface cracks, to keep them from growing into larger cracks.

http://multimedia.3m.com/mws/mediawebserver?66666UuZjcFSLXTtlx&c58&tEVuQEcuZgVs6EVs6E666666--

It's a little involved..look at the photo's see the flap you put in your drill motor like a drill and slap the surface of the case with it. It has tungstun carbide beads that slap the metal and put it in compression like I told you. We do this after grinding goughes/cracks to get rid of surface stresses that can cause cracks and increase the fatigue life.

You really need someone that knows what they are doing to get this right. Aircraft mechanics have to be certified. You have to have the right drill speed, right flap, depends on what the crack or gouge depth is. Not sure if there are local shops in your area that can do this, but it may be less costly than new cases....I don't know.

I thought the very skilled could simulate this by taping lightly with a ball peen hammer to some degree then bond over it but since someone broke some case off bad idea!

We were doing some of this tonight and can take the flap to our skin it's that light.

Anyhow check out some of the photos, the surface you get it's kinda interesting if your into this sorta stuff. It be good on welds too if you had the tools.

Just buying the flap 3M recommends based on your crack, if you can get your drill speed right which is the most important thing might do it. We check our drill speed with a RPM tach. 3M can probably advise on that.

Sorry if I mis-lead anyone.

[nbm]

I got a few questions. Does anybody know what the purpose of updating the 08 to the larger sleeve in the engine case that the swingarm bolt goes thru? Was it to keep the case from cracking? The warranty bulletin says the mount itself will fail but I don't see how the sleeve itself would fail. Also does anybody know if they actually redesigned the case for the 09/10 model to to make it stronger in the area it's cracking? I know they are different part numbers but that could be due to a larger hole in the case to accomodate the larger sleeve.

[TNT]

Originally posted by nbm
I got a few questions. Does anybody know what the purpose of updating the 08 to the larger sleeve in the engine case that the swingarm bolt goes thru? Was it to keep the case from cracking? The warranty bulletin says the mount itself will fail but I don't see how the sleeve itself would fail. Also does anybody know if they actually redesigned the case for the 09/10 model to to make it stronger in the area it's cracking? I know they are different part numbers but that could be due to a larger hole in the case to accomodate the larger sleeve.

I can't speak for BRP but that larger sleeve would help in stabilizing the load the cases see.

[comander420]

So here is my fix for the case crack.

Also I have 2 black about 1/2" dia o-rings that I can't remember where they go. I think that they come off when I took the swing arm bolt out but now I can't remember. Does anyone know where these go?

[nbm]

I don't have to worry about it anymore because I was able to get rid of the biggest piece of crap I have ever owned. The best advice I could give anyone is to not buy one of these. When the ds450 came out, can am had videos with a pro rider saying he "beat this thing to death" and it held up. I call that a flat out lie as I have in no way abused my quad. I had to pay part of the clutch update even tho I complained about it when it was under warranty but at that time there was no fix. Now the case is cracked and they don't want to pay for that either. You can argue that the 2009/10 models are improved but it seems nodoby knows for sure about the engine case. Am I bitter? yes. Do I hope they discontinue the ds450 due to lack of sales? yes. Is this how I really feel about the situation? yes. I bought a 2010 yfz450x so feel free to bash on that if I hurt anybodies feelings. Just remember That I'm not I guy on the outside looking in. I owned one of these machines so I feel I have every right to voice my opinion.

[ZX11]

The welds look strong enough to hold the oil in the case :D


nbm: DS 450's do have problems. Not covering the engine case's known issues is crap. I hope that YFZ450x is more reliable for you. What does the yamaha go for now days? $5,000?

[comander420]

It wasn't leaking yet. It was just a stress fracture but I wanted to catch it before it ruined the case.

[craigmacphee]

I'm looking at puting about $2500 in to my 09 motor. Before I do, will someone show me in a diagram or picture where I should be looking for these cracks. I'm not very motor savvy, so a circle around the problem area would be awesome. Thanks, Craig

[TNT]

You take the front sprocket off the case adjacent to the sprocket there is a protruding boss that has a corner radii where it cracks, I don't think u got to worry w/your 09, there were bushing changes maybe some case gage increase fixed it since the case # changed in 09/10, the 08's are cracking..theres a engine bushing mod I think will help it too.

Heres some interesting stuff....

http://www.aluminumrepair.com/

[comander420]

You would be able to see it from the back of the quad between where the swingarm goes through and the sprocket. Look at the picture where the weld is on mine and it would appear right in the middle where the case has a radius.

[ds450xracer]

Hey tnt you think that stuff would really be stronger then a weld?

[comander420]

I can't answer for sure but anything you stick on it will be bonding to the surface where welding is fusion. I don't see how applying anything on the surface will be better than a weld. But TNT may have a differnt view.

[TNT]

I dunno, I don't see any tested mechanical properties on the site, it says it melts @ (717-737) 500 below alum and I think al is 1200F or so it should be safe since our engines don't see over 500 Id think. I would not use it on exhaust, etc...This stuff is not a thermoset so it will melt once cured. I'm skeptic but you never know, I guess it's worth a try on some test peice it's not that expensive. I'm keeping it in the files just incase I get desperate. :D

[craigmacphee]

thanks

[X400EX]

comander420, is your case still ok?

I'm thinking about doing the same thing on mine, it has hairline cracks right there... and it's a 09.

[ThePhantomRider]

Originally posted by ZX11
So there is a lot of flex in a pyramid aluminum frame? haha. I guess the intro videos from can-am were off base.

does the JB weld help the area before it cracks? Mine hasn't cracked yet but the postings are indicating that it will.

I thought the 2010 cases were the solution. But now it sounds like they will crack also.

There's flex in every frame, there has to be or they would be brittle and really weak. That said, I have posted this before, the frame was not intended for the weight and torque of the 450 motor in there. It was made for a much lighter 250 two stroke so the forces acting on the frame and motor are greater than designed. Hence you get cracks in both caused by each other.

TNT's fix is the best I've seen short of replacement BTW, you guys can learn a lot about structure and strength from him. We've gone round and round on the motor issue and his understanding of force dynamics is outstanding.

TPR

[ThePhantomRider]

Originally posted by nbm
I don't have to worry about it anymore because I was able to get rid of the biggest piece of crap I have ever owned. The best advice I could give anyone is to not buy one of these. When the ds450 came out, can am had videos with a pro rider saying he "beat this thing to death" and it held up. I call that a flat out lie as I have in no way abused my quad. I had to pay part of the clutch update even tho I complained about it when it was under warranty but at that time there was no fix. Now the case is cracked and they don't want to pay for that either. You can argue that the 2009/10 models are improved but it seems nodoby knows for sure about the engine case. Am I bitter? yes. Do I hope they discontinue the ds450 due to lack of sales? yes. Is this how I really feel about the situation? yes. I bought a 2010 yfz450x so feel free to bash on that if I hurt anybodies feelings. Just remember That I'm not I guy on the outside looking in. I owned one of these machines so I feel I have every right to voice my opinion.

It was not a lie, he did beat the quad to death...but it was a lighter 2 stroke. Plus having an experienced rider who can make the big jumps look easy are sometimes easier on quads than we are. Not criticizing your riding ability at all, but sometimes their "beatings" are nothing compared to ours. I mean generally they are lightweight jockeys to begin with, not a normal 200 pound guy.

TPR

[TNT]

Thanks for the kudo’s TPR.

I’ve been looking around the engine compartment lately, it’s seems as though the engine is too large for the engine mounting points, as if as you say a larger engine was an after-thought to the location of the swing arm, rear engine mount, and upper engine mount.

At the rear engine mount (go look at it everyone), you will see the swing arm axis through the engine. A steel sleeve was added to prevent this case crack the idea to put load into the sleeve and away from the case, flex load from the frame engine attach. It did not work, one thing we can do is make sure it is bonded in since there is a designed bond-line gap many including dealers don’t know about. Since there is not enough engine material surround this sleeve the larger hole you drill to install it causes the case gasket and engine material to be too thin causing oil leaks and potential case failure. I just suggested to a guy to build the area up w/epoxy and install an auxiliary gasket, put epoxy not only here but where the crack is/or developing in the fillet radius. If you look close at this area you will see two very small as-casted fillet radius adjacent to one another where it is cracking. You will then see what TPR is talking about, the radii are .060 at best. In structural design we don’t put that small radius adjacent to where large loads from a swing arm, you can see how the case design is extremely tight here as if the frame where designed for a smaller engine. What needs to happen here to fix this properly is move the swing arm axis back, provide adequate room for a proper case design, or reduce the size of the motor.

At the upper engine mount where we've seen case failures too, look at the amount of material that surrounds the bolt through the engine it’s insufficient for the same reason as the lower, the engine is too tall for the frame attach bracket, the case needs more material surrounding the bolt, but the frame rails will not allow it again eluding to the fact that this frame was designed for a smaller motor.

In general, as with the front frame members failing, BRP produced frame segments where major loads from a-arms and engine are induced. Extrustion’s are used and /or thin aluminum bent sheet metal that are .040-.060 thick at best. If you know what an extrusion is, they can be gage (thickness) increased by expensive machining in high load areas, but cost kills the concept. Again major redesign to fix this correctly cost effectively doing a sanity check on the use of extrusions that are expensive to gage change where needed. Not that welds are good, but this is where they come in handy(doublers, etc)....

So IMO it seems to all add up as TPR states to a designer that had no clue what they were doing or frame that was designed for a 250 two stroke smaller motor, I assume the later and Rotax 450 designer was given tight mounting contraints….I know a NASTRAN loads model would never show such small gages and radii in such high load areas good.

Not bashing the quad, many times the market changes in the design process as do the design requirements, I’ve seen this many times it’s not uncommon. :)

[ThePhantomRider]

God knows I love the tech in this quad, I championed it from day one, I was just bummed when I discovered the truth.

The reality is if they had designed the frame to fit the motor it would have been a little heavier to handle the new loads, but they totally could have pulled it off, and yes, market changes dictated the switch and they did the best with what they could given all the time and money already invested in it's development.

TPR

[comander420]

Yes x400, the weld is holding up so far. It only has about 2 hours on it since I had it welded last fall and no races yet. I hope to change that and get a few races in this month so time will tell. I don't think it will crack again in that area. It seems that was about the thinnest area and the fillet were just asking for a problem. I would recomend if you have a hailine crack like I had get it tigged up before it gets worse. If it works, great. If not then you are stuck buying the new cases you were going to anyway. Make sure you tig it not mig it as TIG doesn't produce as much heat as MIG and I threw a wet rag over the output shaft seal area to absorb any heat just in case but when the guy I had weld it got done it was cool to the touch.

[X400EX]

I finaly went with JB Weld a few days ago because I was unsure. If it still cracks, I'll have it welded.

Thanks for keeping us updated! :)

[400exc]

I must be a lucky one because i have a 2008 and yet to have a crack in that area. Hopefully it stays that way.