Sputtering, frozen line? Vacuum leak?

NomadRip · 12-02-2004, 08:45 AM

Picture a moped at top acceleration

Lewdicrous · 12-02-2004, 09:35 AM

Quote:

Originally Posted by NomadRip

picture a moped at top acceleration

Thats how I always picture you

The same thing happened to my bike when it first got cold a few weeks ago and it turned out that over night my carbs went waaaayyyy outta wack.
:dunno

ABearden · 12-02-2004, 10:04 AM

Bike cover and a heater? Move to FI?

That sucks. Sounds similar to when I first pulled the tank off my 500 and put it back together...forgot to move the petcock back to ON. I could rev it in nuetral, but my max rpms under load slowly dropped until it died 1/2 block from my house. I'd check the vacuum line going to the gas tank/petcock, most bikes from what I'm told have a vacuum protection so gas won't flow unless the engine is on. Try running the bike on prime and see if that fixes it (I think I remember your Katana having 4 petcock positions).

Tryful · 12-02-2004, 12:37 PM

And all this occurance when I'm trying to help a fellow rider I saw your post on SCS and felt compelled to post. Well I will respond here to of course!

James, put it on a dyno and find out what the problem is fuel or air. My guess is its fuel it has GOTTEN cold and when the air gets colder it gets more dense so you need more fuel to burn the excess air. My bike was doing the same exact thing as yours. I tore apart the fuel pump and got to the fuel filter and cleaned the filter put it back together and presto instant 1st gear wheelies once again! :woot :happyb

Get in touch with me if you need some help i'm almost convinced this your problem bud.

Lewdicrous · 12-02-2004, 02:57 PM

your bike may not like the cold and may need a vacation to a warmer climate. I know thats what I need!

But fuel additive cleaner stuff sounds like an easy try too.

pulse · 12-03-2004, 03:54 PM

i am having problems with my bike hesitating and stuttering from a start adn once i get over about 2500-3000rpm it runs fine, and it runs fine once the bike is upto temp (about 180 degrees). turned out my ignition coil to the number one cylinder was bad. you bike sort of sounds like that could be a problem :headscratch

so i would say, check your plugs and clean up the carbs, if it still does it then i am betting it may be a coil.

NORTY · 12-06-2004, 11:27 AM

You may want to check for a crack in you carb slide diaphragm(s). Cold weather can make them brittle. Have you purged your carb fuel bowls of water lately? Something similar happened to a buddy of mine with his SC500, turns out a rat was making a home in the airbox. There must have been 300 pellets of dog food in there, perfectly stacked,arranged in rows! Damnest thing I've ever seen! I'm sure most of you don't know what an SC500 Yamaha is. It was a screamer (for it's time.) Imagine a dirtbike that turned 11's in the quarter (@ Carlsbad, no less!) Had a 4 speed tranny and we used 'em all!

Tryful · 12-11-2004, 11:01 PM

So did you ever find out what the problem was? I'm curious as to what it was :dunno

NomadRip · 12-12-2004, 09:08 PM

Quote:

Originally Posted by Tryful

So did you ever find out what the problem was? I'm curious as to what it was :dunno

Sorry Tyler, I thought I posted it already. I tried the fuel additive thing that Earl suggested somewhere else, and after about 80 miles on it, it seemed to clear it out. Think it was water/condensation in the lines or float bowls, but It had just started getting better right before I tore it apart for maint (track prep), and blew out the lines and carbs a bit. Worked well after that, and haven't had a problem since. I am runnign a bottle of that STP fuel additive in every other tank right now, as unfortunately it sits outside, and is pretty moist in the canyon I live in this time of year.

I've still gotta have it re-jetted and tuned by the Dyno-dude, and will hopefully get that done next weekend, so I can see what it will finally feel like when it runs right (dude put a slip-on on it, and didn't rejet, so it runs poorly anyway).

12-02-2004, 08:45 AM	#1
NomadRip Know It All Join Date: Jul 2004 Location: Calabasas, CA (Malibu Canyon) Age: 58 Posts: 401 iTrader: (0) Rep Power: 0 (22)	Sputtering, frozen line? Vacuum leak? Picture a moped at top acceleration Last edited by NomadRip : 03-20-2007 at 02:01 PM.

12-02-2004, 12:37 PM	#4
Tryful Canyon Carver Join Date: Jun 2004 Location: Lakewood, Socal Posts: 515 iTrader: (0) Rep Power: 5 (10)	And all this occurance when I'm trying to help a fellow rider I saw your post on SCS and felt compelled to post. Well I will respond here to of course! James, put it on a dyno and find out what the problem is fuel or air. My guess is its fuel it has GOTTEN cold and when the air gets colder it gets more dense so you need more fuel to burn the excess air. My bike was doing the same exact thing as yours. I tore apart the fuel pump and got to the fuel filter and cleaned the filter put it back together and presto instant 1st gear wheelies once again! :woot :happyb Get in touch with me if you need some help i'm almost convinced this your problem bud. __________________ How do you know where you are? If you don't know where you started from? 2005 999 Duc- Black

12-02-2004, 02:57 PM	#5
Lewdicrous Canyon Carver Join Date: Jul 2004 Location: In my chair Posts: 601 iTrader: (0) Rep Power: 5 (10)	your bike may not like the cold and may need a vacation to a warmer climate. I know thats what I need! But fuel additive cleaner stuff sounds like an easy try too. __________________ If you aint got no cash, I aint got no wiener! SoCal Bike Nights -Jake :hump West Siieeeeede Newbury Park

12-03-2004, 03:54 PM	#6
pulse Know It All Join Date: Jul 2004 Location: San Diego Posts: 343 iTrader: (0) Rep Power: 5 (10)	i am having problems with my bike hesitating and stuttering from a start adn once i get over about 2500-3000rpm it runs fine, and it runs fine once the bike is upto temp (about 180 degrees). turned out my ignition coil to the number one cylinder was bad. you bike sort of sounds like that could be a problem :headscratch so i would say, check your plugs and clean up the carbs, if it still does it then i am betting it may be a coil. __________________ -Jared WSMC #822 Ti2TT - Control Rider TrackVideoz.com

12-06-2004, 11:27 AM	#7
NORTY Know It All Join Date: Oct 2004 Location: Carlsbad Posts: 327 iTrader: (0) Rep Power: 5 (21)	ALWAYS HAVE A GOOD DIAPHRAGM! You may want to check for a crack in you carb slide diaphragm(s). Cold weather can make them brittle. Have you purged your carb fuel bowls of water lately? Something similar happened to a buddy of mine with his SC500, turns out a rat was making a home in the airbox. There must have been 300 pellets of dog food in there, perfectly stacked,arranged in rows! Damnest thing I've ever seen! I'm sure most of you don't know what an SC500 Yamaha is. It was a screamer (for it's time.) Imagine a dirtbike that turned 11's in the quarter (@ Carlsbad, no less!) Had a 4 speed tranny and we used 'em all! __________________ "Let go of my ears darlin', I know what I'm doing!"

12-02-2004, 10:04 AM	#3
ABearden Canyon Carver Join Date: Jul 2004 Posts: 571 iTrader: (0) Rep Power: 5 (10)	Bike cover and a heater? Move to FI? That sucks. Sounds similar to when I first pulled the tank off my 500 and put it back together...forgot to move the petcock back to ON. I could rev it in nuetral, but my max rpms under load slowly dropped until it died 1/2 block from my house. I'd check the vacuum line going to the gas tank/petcock, most bikes from what I'm told have a vacuum protection so gas won't flow unless the engine is on. Try running the bike on prime and see if that fixes it (I think I remember your Katana having 4 petcock positions).

12-11-2004, 11:01 PM	#8
Tryful Canyon Carver Join Date: Jun 2004 Location: Lakewood, Socal Posts: 515 iTrader: (0) Rep Power: 5 (10)	So did you ever find out what the problem was? I'm curious as to what it was :dunno __________________ How do you know where you are? If you don't know where you started from? 2005 999 Duc- Black

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
'07 AMA team line up	SPACEBOY	Professional racing	3	12-29-2006 11:57 PM
British Press Leak Foils Ducati Plans For Worldwide Release	SPEED	General Sportbike Discussion	1	11-10-2006 01:56 PM
FS: PD Pro-line tire warmers SOLD	Shaggy	For Sale	9	10-25-2005 03:15 PM
More -2 and -3 brake line info pretty informative me thinks	Freakshow999	Wrenching/Tech Info & Discussion	0	03-31-2005 02:54 AM
Goodridge Brake Line Q&A	adospeed	General Sportbike Discussion	18	03-04-2005 05:30 PM