n00b exhaust install question - heavy vibration

Hey everyone. I am a new rider, and I have a CBR 250. I bought my bike with a stainless steel Yoshimura exhaust pipe slip on installed. But I found it too loud, and I was getting distracted by it, so I wanted to install the stock one back on. So I pulled off the aftermarket, and put on the stock and now when I drive, at about 6-7000 RPM, the front of the bike is very heavy in vibration, and the sound is very throaty. Is this normal?

it seems to me, that an exhaust can't be the hardest thing to install, so I can't think of what I might've done wrong, but it does seem that the vibration is pretty heavy in the front of the bike now, with the stock exhaust back on. So, if I can't figure this out, I will likely just put the aftermarket one back on. I would rather not have to, because it is a bit loud for my area of town

please help!

Maybe exhaust leak where the header connects to the engine. It might also be that it needs new gaskets?

Ok - so I did forget to mention it, But I did feel underneath the bike and there is a little bit of heat coming through a tiny hole in the original stock pipe. But I believe this hole is intentionally there ( in other words, it isn't due to rust). Obviously I can't close off the hole with my hands to test it out because it's too hot, but there is a little gray rubbery ring (it's kinda like rubber but kinda like plastic, I can't describe it) that came around the muffler area that I just shoved into the pipe when mounting the stock muffler.

do you think this gray ring could be meant to cover that hole?

I also forgot to mention - that I wanted to go back to stock so that my insurer would cover it. State Farm said they would not cover the bike if there were any modifications which resulted in a performance increase done to it. I can't confirm the Yoshimura exhaust results in a performance increase. I read a few threads on this, did anyone ever confirm if a slip-on exhaust would be considered a performance increasing modification under insurance?

Meantime, I removed the exhaust pipe and reinstalled it again with the gasket in there hard, and unfortunately its making no difference So angry, just bought the bike and already an issue!

marktwothousand said:

I also forgot to mention - that I wanted to go back to stock so that my insurer would cover it. State Farm said they would not cover the bike if there were any modifications which resulted in a performance increase done to it. I can't confirm the Yoshimura exhaust results in a performance increase. I read a few threads on this, did anyone ever confirm if a slip-on exhaust would be considered a performance increasing modification under insurance?

Meantime, I removed the exhaust pipe and reinstalled it again with the gasket in there hard, and unfortunately its making no difference So angry, just bought the bike and already an issue!

Click to expand...

There's probably a loose mount somewhere in the exhaust system. There's that of the gasket isn't installed properly.. That small hole is a drain hole in the event rain water gets in the pipe.

Thank you very much Jimsun.

For now, I am going to have to say good riddance and put the aftermarket back on again I have to say, the overall bike just feels and handles better with the less weight - the change is significant. I'm just concerned for insurance because the Yoshi pipe specifically says FOR RACE TRACK USE ONLY.

I would really like to get the stock working properly though. In taking it off a second time, I destroyed the graphite/wiremesh gasket I am going to have to find another one, can I order these at any Honda automotive dealership or do I have to go to a powersports dealership? Ultimately, I will likely have to call in a mobile mechanic as I can't transport the stock to a garage with the bike, its just too heavy and unwieldly for a backpack

marktwothousand said:

I also forgot to mention - that I wanted to go back to stock so that my insurer would cover it. State Farm said they would not cover the bike if there were any modifications which resulted in a performance increase done to it. I can't confirm the Yoshimura exhaust results in a performance increase. I read a few threads on this, did anyone ever confirm if a slip-on exhaust would be considered a performance increasing modification under insurance?

Meantime, I removed the exhaust pipe and reinstalled it again with the gasket in there hard, and unfortunately its making no difference So angry, just bought the bike and already an issue!

Click to expand...

Lol exhaust and intake most definitely are not something to worry about insurance wise. Exhausts rot out all the time, and replacing with OEM is impractical at best on old bikes. They're concerned about superchargers, not 1hp gains from aspiration. If that were an issue, you couldn't run 91 octane if it happened to make your bike perform better.