Have a customer running UPP manifolds with the bigger VM's. What do you think is causing this? weight, heat, fuel, overtightened?
I've sold lots of these manifolds and haven't had this come up before.
(https://i1219.photobucket.com/albums/dd429/John_Rodenhiser/2%20Stroke%20World%20Tech%20Data/20190303_103421%20003_zpsnr38ytn0.png) (https://s1219.photobucket.com/user/John_Rodenhiser/media/2%20Stroke%20World%20Tech%20Data/20190303_103421%20003_zpsnr38ytn0.png.html)
I have no real answers but by the look of the picture I would say weight didn't cause the initial failure. Something else caused the rubber the crack/get brittle and then the weight of the carbs made them come off like that. It also looks like it happens to both sides in the picture.
How old are these manifolds?
they're about a year old, it's happened to him 3 times
Are his carbs a perfect fit for the manifolds, or is he forcing larger spigots into the manifolds, stretching the rubber?
I believe constant stress in the rubber will lead to premature failure. Also, what kind of gas is he running?
In any case, some kind of secondary support for carbs or filters could be useful, and fairly easy to do.
^ this may very well be true. I had some that tore finally after 6/7 years? but i had unsupported big body VM35's on it. The split along the intake suggests exactly what was said about.. maybe the carb is too big OD. Id def support the carb on the back, i did it on mine after the last set went. :twocents:
I don't know, I'm thinking it is either the fuel he is running or something he is spraying on the clean the bike with. You can see at the bottom of the manifold where the spigot meets the base there is a crack forming. I don't think one would form there like that from being over stretched but maybe.
Like Mark mention though, to crack along the length would suggest being stretched. He isn't running something like E85 for fuel is he?
also, how tight is he making the hose clamps? :umm: that will cause a shear line :twocents:
I'd suggest that the clamps are too wide and as they clamp down on the manifold, they are pushing the carbs backwards which may be the cause of that shearing.
Manifold and carb OD mismatch compounded by excessive thightening.
over Thightening. Bad for intakes. :dawg:
(sorry couldnt help it)
I'll throw this out there, I have the same issues with the UNI filters on my 350. I've been through two of them already and need another. The tear is pretty close to what is shown in John's picture. The UNI's are slightly larger than the PWK's but still clamp down tight on the carbs. I'm thinking that it may be a fuel thing, I don't always have the opportunity to get E free fuel around here. Maybe Gill is correct also with the excessive tightening.
Thanks for the feedback guys, much appreciated.
John
Interesting, I have never had that problem with Uni filters. Typically my Uni's are good for about 3 years and then the foam material starts to fall apart.
I run non-ethanol gas all the time.
Quote from: Hawaii-Mike on March 04, 2019, 02:05:54 PM
Interesting, I have never had that problem with Uni filters. Typically my Uni's are good for about 3 years and then the foam material starts to fall apart.
I run non-ethanol gas all the time.
same here.
Given the fact that there appears to be mud? packed on the backside of the cylinder, is the guy offroading with the bike? Lots of gravel roads?
Has he sent you any manifolds back?
What do the insides look like?
Is he steam cleaning the bike, using a pressure washer at a carwash perhaps?
I know guys in the sled world that run some alternative fuels, maybe he is using a special blend thats killing them?
Quote from: 2strokesforever on March 05, 2019, 10:44:09 PM
Given the fact that there appears to be mud? packed on the backside of the cylinder, is the guy offroading with the bike? Lots of gravel roads?
Has he sent you any manifolds back? No he's in Bali
What do the insides look like? haven't seen them
Is he steam cleaning the bike, using a pressure washer at a carwash perhaps? something is going on, they don't look quite right to me, heat or fuel or something got to them.
I know guys in the sled world that run some alternative fuels, maybe he is using a special blend thats killing them?
Thanks for all the feeback guys, very helpful. He may have had multiple issues going on, unsupported carbs, fuel, etc.
What is the material of the UPP manifolds?
Is it rubber or urethane?
urethane
Quote from: m in sc on March 06, 2019, 07:42:42 PM
urethane
I asked because where the two pieces separated looks like failed poly engine mounts.
The "mud" looks to be of wasp construction. Must be in the Southern half of the country. Those damn things love to inhabit motorcycles in the garage.
IR8D8R