popping exhaust at idle? - SV650.org

19-08-06, 09:56 PM

i have a 2000sv650 with a factory jet kit, bmc race air filter, and a slip on scorpion exhaust.

when the bike is idling every now and then it will pop. about 2x's a minute. the pops are noticeable.

the bike is an ex race bike

does anyone know what the prob is? is it running to lean or rich? is it a big deal?

thanks!

Kyle

19-08-06, 10:06 PM

i just read another thread about this.. will this popping at idle adversely affect the bike?

thanks guys!

20-08-06, 12:17 AM

Interesting...your bike is the same year, has almost the same mileage and mine appears to maybe have been an ex-race bike (lockwired drain plug and various bolts, frame sliders, and some minor crash damage on both sides). Mine hasn't been jetted though and mine backfired once or twice every few seconds.

Since yours was an ex race bike it might be a bent valve, but I doubt it. I'm gonna go with exhaust isn't sealing at all the fittings. How's the bikes starting? Does it need some choke for a short time to start and stay running or does it start right up and idle perfectly without any choke? If you answered yes to the former than it could be running lean at idle...the latter is obviously a slightly to moderately rich condition. I'd check the idle mixture screw which is relatively easy to get at. I'd remove the carbs and airbox anyway just to make sure the little coupling sleeves are properly mounted and aren't leaking.

If this doesn't solve your problem...go for a long ride then let it sit for a day and it should run perfect...at least that's my extent of experience with backfiring and the sv650.

20-08-06, 01:12 AM

hmmm if the engine is cold i use the choke it starts right up then after a min. i take the choke off. if the engine is warm i dont need choke. runs like normal. im thinkin when they tuned it for racing they didnt give a crap about how it idled just how it performed up top?

up top it really gets up and goes... down low i tend to get some surging while cruising at a constant speed at 5-5500rpm roughly. but that seems to be going away. i've only ridden it 100 miles since i've had it as of yesterday!

thankS!

20-08-06, 08:37 PM

If it's properly jetted and the carb needles and such are all set right then it should not run too lean or rich in any rpm. Are you sure it's jetted? My bike had a filter and full yoshi exhaust on it and it wasn't jetted and nothing on the carbs was adjusted...ran alright until you start getting used to the bike and realize things are quite as good as you thought they were.

You might want to consider just checking the carbs over to make sure the things that should have been adjusted are actually adjusted...

a good write up is here: http://www.geocities.com/catpoopman/Johns_bike.html

the shims for your carbs should still be on the needles (if you lose them or the previous owner chucked them you can purchase some from the site for like $4...) so both the air/fuel adjustment and needle shimming are free mods and definitely worth checking out to smooth your bike out and possibly avoid any lean/rich conditions that may exist.

21-08-06, 01:31 PM

im pretty sure the bike was jetted. the guy seemed trustworthy. i lowered the idle from 1700 to 1000 and the popping as gone away. when there isnt a load on the engine i get popping, or up to 3k i will get some popping, other than that the bike is running just fine.

i am not getting bluing of the pipes either so that's good.

19-08-06, 09:56 PM	#1
toyotafj40s Guest Posts: n/a	popping exhaust at idle? i have a 2000sv650 with a factory jet kit, bmc race air filter, and a slip on scorpion exhaust. when the bike is idling every now and then it will pop. about 2x's a minute. the pops are noticeable. the bike is an ex race bike does anyone know what the prob is? is it running to lean or rich? is it a big deal? thanks! Kyle

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19-08-06, 10:06 PM	#2
toyotafj40s Guest Posts: n/a	i just read another thread about this.. will this popping at idle adversely affect the bike? thanks guys!

20-08-06, 12:17 AM	#3
klohiq Guest Posts: n/a	Interesting...your bike is the same year, has almost the same mileage and mine appears to maybe have been an ex-race bike (lockwired drain plug and various bolts, frame sliders, and some minor crash damage on both sides). Mine hasn't been jetted though and mine backfired once or twice every few seconds. Since yours was an ex race bike it might be a bent valve, but I doubt it. I'm gonna go with exhaust isn't sealing at all the fittings. How's the bikes starting? Does it need some choke for a short time to start and stay running or does it start right up and idle perfectly without any choke? If you answered yes to the former than it could be running lean at idle...the latter is obviously a slightly to moderately rich condition. I'd check the idle mixture screw which is relatively easy to get at. I'd remove the carbs and airbox anyway just to make sure the little coupling sleeves are properly mounted and aren't leaking. If this doesn't solve your problem...go for a long ride then let it sit for a day and it should run perfect...at least that's my extent of experience with backfiring and the sv650.

20-08-06, 01:12 AM	#4
toyotafj40s Guest Posts: n/a	hmmm if the engine is cold i use the choke it starts right up then after a min. i take the choke off. if the engine is warm i dont need choke. runs like normal. im thinkin when they tuned it for racing they didnt give a crap about how it idled just how it performed up top? up top it really gets up and goes... down low i tend to get some surging while cruising at a constant speed at 5-5500rpm roughly. but that seems to be going away. i've only ridden it 100 miles since i've had it as of yesterday! thankS!

20-08-06, 08:37 PM	#5
klohiq Guest Posts: n/a	If it's properly jetted and the carb needles and such are all set right then it should not run too lean or rich in any rpm. Are you sure it's jetted? My bike had a filter and full yoshi exhaust on it and it wasn't jetted and nothing on the carbs was adjusted...ran alright until you start getting used to the bike and realize things are quite as good as you thought they were. You might want to consider just checking the carbs over to make sure the things that should have been adjusted are actually adjusted... a good write up is here: http://www.geocities.com/catpoopman/Johns_bike.html the shims for your carbs should still be on the needles (if you lose them or the previous owner chucked them you can purchase some from the site for like $4...) so both the air/fuel adjustment and needle shimming are free mods and definitely worth checking out to smooth your bike out and possibly avoid any lean/rich conditions that may exist.

21-08-06, 01:31 PM	#6
toyotafj40s Guest Posts: n/a	im pretty sure the bike was jetted. the guy seemed trustworthy. i lowered the idle from 1700 to 1000 and the popping as gone away. when there isnt a load on the engine i get popping, or up to 3k i will get some popping, other than that the bike is running just fine. i am not getting bluing of the pipes either so that's good.