Running with no exhaust

My son has a 97 VFR 750, and he insists on running it without the exhaust pipe on it. He says it sounds cool. Will this have any long term effects on the motor or valves, or will it just not run as good?

 

Yeah, this will have a long term effect on motorcyclists as your community demands that all bikes have stock exhaust, no aftermarket pipes. Then his bike will be junk as no more stock pipes.

He is young, and the loud exhaust is fun... until he has to go a long ride on a bike that has to ride next to the loud pipe. Maybe you can force that looong ride with him so he hears how "fun" the open pipe is. Better yet, get his riding buddy's to tell him it sounds cool, but is painfully loud.

Start to ignore his requests claiming your hearing has been damaged by his bike. example:
Son: Dad can I borrow $20?
Dad: Huh?

 

If he really wants to do that, I've got a modified '93 with a pipe that has been gutted and shortened, still better than leaving the back half off but not much. Sounds like a small block Chev V8 with no mufflers, which is cool for about a half hour before the headache sets in. With earplugs I'm good for about an hour before *they* give me a headache. It also ran like capital-C CRAP, ran about 15 degrees hot (lean) and got significantly worse mileage until I spent $300 getting a jet kit and having it installed and tuned, and it still runs worse than it did before. Sure, it's 10 pounds lighter but it sure doesn't add any performance.

I'd be happy to swap exhausts with him, or bikes for that matter just to get a nice quiet, headache free ride back.

 

I would not be surprised if he burns a valve ugg get him a pipe even after market.

 

A guy that used to be the Head Factory Mechanic for Harley's Scott Parker told me that Harleys run with the short shotgun/drag piped had a tendency to crack and shatter exhaust valves. This was due to eratic sound waves and cool air finding their way quickly back to the exhaust valve.
I would imagine this would apply to even Japaneese valves.
As far a power is concerned, the exhaust pulse is a very important factor in maintaining horsepower. The back pressure created by the pipe helps kep the fresh air/fuel charge in the cylinder during valve overlap.
The cost of repairing the engine after a valve shatters may not influence your son, but the loss of horsepower, that his friends will surely notice as they leave him in the dust, may be your best selling point here.
Good luck

 

I too chopped my stock pipe on my 93 Vfr750
I didnt notice any increase/decrease in power either way.
Though I think it would be helpful to install a Jet kit to smooth out my idle a bit...runs a little choppy on initial start up.

Does any one know where to get a "factory" jet kit?
after investigation, it seems everyone points to the "factory" kit as best.
I've heard mixed things about some of the others...Dyno, 2 Bros..etc., etc.

I cant seem to find anywhere that has factory kits for 90-93 VFR's

Thanks-
Steve

 

Factory Pro Racing http://www.factorypro.com/

Basically have to order from them for the VFR as no one in Canada at least stocks them.
I have a UMI (Dynojet) kit in mine and while it is better, it's not smooth as the bikes with Factory kits I've ridden. Your results may vary due to the skill of the tech setting it up.

 

Thanks for the feedback.