riding without a pipe

I do have a proven theory. Had an old MG 1200 sedan that I drove back and forth from home to Norfolk Va.,about an 8 hour trip. One night on the way home the car developed an exhaust leak. Little did I know that the leak was right after the manifold. Broken EX pipe. By the time I got home I was down to a twin cylinder.
Yanked the head off and found that #2&3 ex valves had a nice "V" carved into the seat area. Had the valves & seats replaced and reinforced the ex pipe with a big hunk of steel from the manifold to the first bend . Put another50,000 on that car with no prob. Proof ! Just a side note: When Racedad says "don't do it!" I can't inagine why you'd want to do it anyway or need proof. He knows what he's talkin' about. I hear he's pretty good at chasin' the puddle too.:up:

 

Yes, Rich it burnt a valve. less backpressure = leaner mixture = high cylinder temps = inability of valves to cool enough during closed period = melted area of contact between valve and head = high pressure of combustion displacing liquid metal of valve (remember, the valve does not cool while the seat does while open) = weak spot in valve sealing area = eventually a big 'ol hole. Proof, sure. Don't adjust your valves, it'll do the same thing. Headers ---- Good for power, mufflers ---- good for ears. Enough of this burnt valve nonsense. Think before you type people, you sound like my 13 year HS students. But then again, maybe some of you never made it that far.

Yes if you ride with no muffler a Stage III kit is what you need. Grin.

 

a little off subject, but can you run a gp 2stroke without a muffler? i had a can rattle loose the other day at a track day but was too worried about how it would effect the bike to take it off and run the bike without it. as what has been stated in earlier posts, at a minimum it sounds like you would need to richen up the jetting.

 

Old=carbureted vehicle. We're talking about a fuel injected bike that can at least somewhat compensate for fuel mixture.
Jet your carb to have NO exhaust leak. Pull the header off. See what happens. That's different.

 

You're totally right & just as an FYI, i was pointing out that even no exhaust at all would not bend a valve.

 

How does nitrous oxide injection work?

Gusts of cold air & bent valves.
I love this place...

 

You can run a two stroke with just a stinger. It will alter the jetting but it may also run quite a bit cooler without the muffler. Use caution but when strokers ruled in F1 and F2 I don't remember anyone seizing when they lost a muffler. OTOH- I may just not remember........