Nitro , expansion joints breaking , MCX

[Sleds R Fun]

Having trouble keeping expansion joints in MCX 270 Nitro. They seem to break when running 14#'s approximate tree riding in and out of throttle. Any suggestions why I'm breaking them so often? I'm not running an AF gauge , has anyone noticed a lean spot? Run 50/50 fuel.

 

[BBNytro]

That is a new one on me! Did you buy an aftermarket header or weld up the flange yourself? It sounds like you have some serious stresses on the expansion joints. As for fueling I have found the MCX to be a little on the rich side. I would suggest cutting the flange piece off and starting again making sure the turbo is tightened down after it is mocked up.

 

[Sleds R Fun]

Joints

Must be some stresses on the the joints! Seems like after every 2 rides I'm replacing a joint, all on various cyclinders. I'm going to mock a new system like you suggest unless there is some sort of beaded flex pipe (mesh)a person could purchase.

 

[Tuesday]

we have had them crack/break from heat and wear but not from stress of a few rides. To much pressure on them.

Daves header from redline eliminates the donuts that might help. You will need a new header eventually anway.

 

[dexter]

Sounds like movement is the problem. Check header brace on the tunnel. I have broken those rivets a few times. And I have also broken that support on header before. Put alpine header in and no problems since.

 

[BigFish BC]

your motor mounts tight almost sounds like the motor is twisting under load,of coarse you would think you would have belt probs too.

 

[sledheadd]

we have had them crack/break from heat and wear but not from stress of a few rides. To much pressure on them.

Daves header from redline eliminates the donuts that might help. You will need a new header eventually anway.

I went with Dave's header after finding all 3 bellows cracked and also the header was cracked at 2 different places.
Sled runs better then it ever did now.
I have been running the same clutching for 5 years, now since installing Daves header I'm now hitting the rev limiter @ 13 psi instead of 15 psi.

 

[Sleds R Fun]

Joints

It was #3 cylinder again, 2nd time this year. I have to "stretch" the expansion joint a little between the cylinder and clamp for a tight fit. Thinking these expansion joints don't want to be stretched but need to be in neutral position when installed. Otherwise header is in great shape. May have to modify slightly for tighter fit.

 

[SylvanLaker]

It was #3 cylinder again, 2nd time this year. I have to "stretch" the expansion joint a little between the cylinder and clamp for a tight fit. Thinking these expansion joints don't want to be stretched but need to be in neutral position when installed. Otherwise header is in great shape. May have to modify slightly for tighter fit.

Dave here at Redline. if they aren't lined up perfectly they fail sooner. You need to fix that header and make it perfectly straight or else you will break down again. I strongly suggest you remove the header brace that is midway along the header. it cases failures sooner. Our headers are perfectly lined up and the bellows will have a lot less stress on them.. Don't proceed to install it if it won't line up.. happy to help if you need advice. call the shop anytime.

 

[Wiskey7]

Broken Bellows.

I have the Red Line Header on my TNytro, it is lined up good, but have still broke 2 bellows? They did have alot of miles on them around 5000miles.

 

[Sleds R Fun]

Header

Thanks Dave for the input. Just curious why you feel the extra support can speed up failure? Are your headers pre wielded to an exact size when purchased? (Ie: do you require any existing pieces from my header)
It's out about 2-3/8th out , but its enough the clamp wont go on without stretching. I better get the weirder out!

 

[SylvanLaker]

well i did some testing when i designed them and the the engine moves about 1/8 under load max and the turbo bounces around too so to speak It doesn't uch but when fixed in the middle to the tunnel it has to resist movement on both sides. My system just mounts on each end so the header is free to "float" and not realize additional stresses. further the bellows dont see as much twisting stress. bottom line is you don't need the middle hanger anyway so why use it.. its kinda hard to explain but if you think about it it will make sense. Proof is in the results too, the bellows fail a lot less without the bracket. too bad nobody makes a better bellow..

PS our headers remove the donuts and are a tolerance slip on..