Popping on Overrun

bmetcalf

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My Rap started popping on the overrun recently. Is that caused by air leaks? Carb and exhaust system?
 

davidd

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Bruce,

I am with Greg. I would check the exhaust gaskets and see if there is anything left.

David
 

bmetcalf

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Thanks for the exh nut/gasket suggestions. The nuts are tight, but I'll have the pipes off soon to adjust the shift mechanism so I can go from 4th to 3rd reliably, so I'll check the gaskets then and give the threads on the heads and nuts a good cleaning.

I rode to this event on Sunday http://nobodymotorcycleclub.blogspot.com/2009/06/blind-lizard-rally.html It is from '09, but gives the flavor. My Rap is behind the Indian in this pic http://2.bp.blogspot.com/__Do6TtvwN...Ac/9J_a9l7IQxI/s400/Blind+Lizard+2009+039.JPG The skies started threatening rain, so I left and once on the interstate highway, my throttle slipped and I was going 75 and wasn't able to wrestle it down until just before my exit.

The Triking at the bottom of the page is Steve Hamel's.
 

hrdsuper90

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Nothing really to wear out there but could try weakening a little with the air screw as fuels do change. Maybe slight flooding which could be worn feed needles.

Chris C.
 

b'knighted

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My twin developed a similar fault. A friend said following me was like being a fighter pilot following a rear gunner as my backfires were spitting flame at him. I believe the fault on my bike to be a result of the (t)rusty exhaust system developing a pinhole in the top of the siamese joint. About thirty years ago I paid Stuart Towner £8 for this exhaust and am loath to replace it while 99.9% is still sound. The (free) Goldie "silencer" had to be replaced for last years MoT as it had lost its twitter, along with a few square inches of steel from the lower inside. The half that showed under the rear cowl still looked OK but all the road muck had run from the inside of the cowl over the inside of the silencer. Similarly the right side panel drops any road dirt that hits its inside on the top of the front cylinder pipe and the top front of the joint is a collection point where muck can start the rust.
 

bmetcalf

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Flames? Cool!! I love those photos of turbo Porches at Le Mans with fireballs coming out of their exhausts.

I probably should see if the idle adjustment needs to be changed. After installing the Roy Price ATD, I'm not used to it idling on its own without a lot of macho throttle blipping.

My silencer is SS and the pipe is only 22 years old or so! But, I'll have the pipes off soon to make sure my last time of putting in the timed breather was on the right tooth. I can inspect things then.
 
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