While working on the exhaust on my new powerhouse 50mm overbore, I popped an ear on the exhaust flange. I tried to JB Weld the stud back in, but am afraid to tighten it down like it should be, and I've got an exhaust leak. Now my powerhouse barely pulls out of the driveway.
Thoughts?
EDITED: Exhaust leak not the problem
Exhaust leak Not the Problem
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Exhaust leak Not the Problem
Last edited by Lunytune on Thu Jul 23, 2009 11:03 am, edited 1 time in total.
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scooterwerx
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Re: How serious is an exhaust leak?
2 strokes live because of exhaust principles. did the stud strip, pull out, or actually break the flange?
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Wheelman-111
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Re: How serious is an exhaust leak?
Greetings:
The wise Werx submitted:
JB weld works OK for moderate-heat locations in a liquid-cooled block, but it is plastic-based after all, and temps well above the 400-ish degree limit of the epoxy are likely to be encountered around the exhaust port and flange. A machine shop (or Mr. Werx) could weld the broken chunk back on, re-tap the stud threads and make a permanent repair. Option 2 is a new cylinder...
The wise Werx submitted:
I concur. However a minor leak would not necessarily cripple the Mighty Ruima to the stated degree. Are we talking a wisp of a leak or half-lungful? Might be something else. If a minor leak persisted long enough, it could scorch the rim of the port, melt a corner of the piston and lose ring seal. Dismantling for inspection is indicated.2 strokes live because of exhaust principles. did the stud strip, pull out, or actually break the flange?
JB weld works OK for moderate-heat locations in a liquid-cooled block, but it is plastic-based after all, and temps well above the 400-ish degree limit of the epoxy are likely to be encountered around the exhaust port and flange. A machine shop (or Mr. Werx) could weld the broken chunk back on, re-tap the stud threads and make a permanent repair. Option 2 is a new cylinder...
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Re: How serious is an exhaust leak?
Flange broke about 1/2 way across the hole. So I've got "some" threads to hold, and I Jb-Welded around it.scooterwerx wrote:2 strokes live because of exhaust principles. did the stud strip, pull out, or actually break the flange?
Wheelman, this is a Tazland kit, not a Ruima. I wrote Mark about it. Don't know what he will do about it. I really do believe it was poor casting or too thin of a flange. The leak is more than a whisper, but not really a lung full.
I saw a thread where a guy had doped up heat tolerant gasket dope around the donut gasket. Wonder if that would hold enough to solve it.
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Wheelman-111
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Re: How serious is an exhaust leak?
Greetings:
Quoth Tune:
It sounds like it's enough of a leak to explain lackluster performance fully. Hope so.
Dope and Plastic can't sustain the tensions across those studs, particularly heated to 800 degrees. Remember there's a fair bit of pressure pulling that headpipe out, too. I'd replace the jug or see if it can be welded. $0.02
Quoth Tune:
Uhh, whut's a Tazland? Linkage?Wheelman, this is a Tazland kit, not a Ruima. I wrote Mark about it. Don't know what he will do about it. I really do believe it was poor casting or too thin of a flange. The leak is more than a whisper, but not really a lung full.
It sounds like it's enough of a leak to explain lackluster performance fully. Hope so.
Dope and Plastic can't sustain the tensions across those studs, particularly heated to 800 degrees. Remember there's a fair bit of pressure pulling that headpipe out, too. I'd replace the jug or see if it can be welded. $0.02
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Re: How serious is an exhaust leak?
Tazland001 is a member of the forum, selling on eBay as "chopchop". He's the one with the overbore Spree kits, and several other scooter items.
I've used JB Weld very successfully in a lot of places, but never in a place with this much heat or in such a repair with so much stress. That "wisp" of a leak could very well be closer to a 1/2 lung, I don't know. I do know it was running fine until I had my exhaust problems. (muffler broke off due to support bolt coming lose and falling out. Weight and vibration broke pipe.) Now it runs similar to not having airbox on. Idles, but no power. I doubt I have a ring or piston problem, as it still takes pretty good kick to start it. Electric starter just won't crank it over. It's got a humdinger compression. But it starts on first kick.
I've used JB Weld very successfully in a lot of places, but never in a place with this much heat or in such a repair with so much stress. That "wisp" of a leak could very well be closer to a 1/2 lung, I don't know. I do know it was running fine until I had my exhaust problems. (muffler broke off due to support bolt coming lose and falling out. Weight and vibration broke pipe.) Now it runs similar to not having airbox on. Idles, but no power. I doubt I have a ring or piston problem, as it still takes pretty good kick to start it. Electric starter just won't crank it over. It's got a humdinger compression. But it starts on first kick.
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Wheelman-111
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Re: How serious is an exhaust leak?
Greetings:
Quoth Tune:
Quoth Tune:
I guess you can't blame the casting quality for that one. The muffler hanging at the end of that long headpipe can certainly break cast iron if you're riding it around. Bum luck or Severe Shortage of Loctite...(muffler broke off due to support bolt coming lose and falling out. Weight and vibration broke pipe.)
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Re: How serious is an exhaust leak?
No, it broke on the reinstall. Could be wrong but it felt solid when I pulled it to take to the welder.Wheelman-111 wrote:Quoth Tune:I guess you can't blame the casting quality for that one. The muffler hanging at the end of that long headpipe can certainly break cast iron if you're riding it around. Bum luck or Severe Shortage of Loctite...(muffler broke off due to support bolt coming lose and falling out. Weight and vibration broke pipe.)
As far as the original muffler problem, I think this bike may have been an abused pit bike in its former life. How are these aftermarket muffler?
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Re: How serious is an exhaust leak?
Sorry to here about you problem.Take it back to the welder.It can be welded with a nickel rod ,meant for cast iron.He will probably want to preheat the area . Then you will have to re-tap the hole.That would be the best way.Good luck.Carp
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and they all need lots of love !!!
Re: How serious is an exhaust leak?
Carp, the welder was the guy who welded the pipe and muffler back together. He's a muffler man. Doubt he could do what you're talking about. The only guys I know like that in this county are now dead. Two more steps and you fall off the edge of the world. Or as they say, "they pipe sunshine to us".
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mousewheels
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Re: How serious is an exhaust leak?
This is a cyl that came broken on a used bike. Guy had simply rigged it with a nut on the backside. Don't know how long he rode it for, but I rode it a month or 2 before replacing it. Didn't have any problems, but couldn't get to feeling good about leaving it.
Re: How serious is an exhaust leak?
That is very similar to what my cylinder would like like before the JB Weld. I didn't think about a nut on the backside, but that would be a consideration. It would need an all-thread to reach through that deep. No, maybe the original stud turned backwards might reach in that far. Worth a try if I can clean the JB-weld off. It just might salvage a new cylinder.mousewheels wrote:This is a cyl that came broken on a used bike. Guy had simply rigged it with a nut on the backside. Don't know how long he rode it for, but I rode it a month or 2 before replacing it. Didn't have any problems, but couldn't get to feeling good about leaving it.
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Re: Exhaust leak Not the Problem
It was "GSI do or die", so I loosened everything up, torqued the bad stud with JB Weld, then torqued the other side and finally the muffler mount. Problem still there.
Now for Paul Harvey's "the rest of the story", while down, I had ordered a filter and air box cover, and installed during the down time. That's the "all things equal" which messed up the factor.
I pulled the cover and filter... Banshee is back flying, full power. Put the airbox cover on without filter... bad... left the cover off, Power.
Who knows how long the JBWeld will last, but in the mieantime, Banshee is back in the race. When it breaks, I'll put a nut on back side of stud and braze it on. That's probably what I should have done instead of JB Weld.
Now for Paul Harvey's "the rest of the story", while down, I had ordered a filter and air box cover, and installed during the down time. That's the "all things equal" which messed up the factor.
I pulled the cover and filter... Banshee is back flying, full power. Put the airbox cover on without filter... bad... left the cover off, Power.
Who knows how long the JBWeld will last, but in the mieantime, Banshee is back in the race. When it breaks, I'll put a nut on back side of stud and braze it on. That's probably what I should have done instead of JB Weld.
Friends don't let friends buy Chinese bikes
Re: Exhaust leak Not the Problem
just get some exhaust studs. put them back in their original holes and weld them back up. easy fix...The real way would be to weld up the holes , then retap, but i would do the stud way, way faster and cheaper to do.
aloha
D
aloha
D
Re: Exhaust leak Not the Problem
Have you ever welded cast iron?tru72 wrote:just get some exhaust studs. put them back in their original holes and weld them back up. easy fix...The real way would be to weld up the holes , then retap, but i would do the stud way, way faster and cheaper to do.
aloha
D
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