hello to all
i bought a use 97 cbr 600 f3 front upper fairing section damage and not starting it came with no muffler the guy sold it and the guy gave him his
ok his must of being a newer bike this is an oem muffler has a o2 sensor and catalyst so for now i plug the o2 sensoe hole then i gutted the inside part to get the honey comb out for the catalyst part i have it on the bike sounds good and quiet but if the bike had an after market exhaust it should have been jetted rite.???? if so now that i have this oem muffler should i need to re jet bike runs good except for idle it smells rich and either stall or goes high then low but it won't stay idle for more than a minute at a steady rpm .thanks

 

Diagnosis of this type of problem can be a real pain. For one, you have no idea how the bike ran before. You may end up chasing things that aren't even the problem.

From the description, it sounds like the carbs are out of sync. But,
without the proper muffler on there, you may never get the bike to idle correctly. The reason being that most mufflers are tuned for a specific engine. They actually scavenge the exhaust and help the gasses escape quicker. When you have a muffler that is not tuned for your engine, the exhaust pulses sort of run into each other and they slow each other down, then they group up and go out the pipe. This is why you get a high to low rpm. There is quite a bit of time spent on muffler design and each engine has different characteristics. Some engines have a lot of backpressure while others do not. It all depends on what the bike was intended for.

If the bike had an aftermarket exhaust on it previously, it doesnt mean it was jetted. A lot of times a jet kit is not needed. A jet kit can help the bike to gain some more power or richen a lean condition for the muffler, but most slip ons don't require fuel modifications.

My suggestion would be to get a muffler on there that is intended for that bike and start from there. You could end up trying to get the carbs synced and leaned out for the exhaust you have, but it may never run right and there will be a lot of time and money wasted.

 

what would be a good muffler for this type of bike that would not brake your wallet

 

If you want to remain quiet, find an oem muffler. Ebay will usually have one or two of them and usually can be had for around 50 bucks or less. I might be mistaken, but I think the F2 and F3 mufflers are the same, so that should give you a little range to find one.

If you want to go aftermarket, I run a yoshimura. Some others would be two brothers, Micron, Jardine, scorpion, Leo Vince. Those are all decent quality slip ons that are on the lower end of the price scale. their are cheaper chinese slip ons out there, but I think I would stay away from them. Just remember these slipons will be significantly louder than stock. if you want to have a quiet bike, then find an oem one. Oh yeah, I would have suggested D&D, but they are rediculously loud, unless thats what you want. they are a decent quality pipe, just obnoxious.

Also, your going to want to stay away from custom "shorty" or "gutted" exhaust. Its almost impossible to tune your bike for set up like that.

Just remember that placing a new slip-on on the bike may not cure your issue, but will certainly make it easier to diagnosis the problem if it doesnt fix it. I would still be leaning towards the carbs not synced correctly, but there just isnt a good way to know until you get a proper muffler.

 

My bike came with a D&D, it was the most godawful thing I've heard since my Civic broke its timing belt and the resulting series of backfires blew the muffler in half

Put a stock exhaust back on and I swear it's quieter at 5000 rpm than the D&D was at idle.