Stalling off Idle (am I lean or rich?) - Sportbike Addicts

Bster13 · 03-27-2006, 10:58 AM

Bike (00' SV650) never seemed to be jetted correctly, with the rear cylinder running way rich. Bike would fire on both cylinders until 5kRPM with a loud backfire (unburnt fuel igniting I suppose) and then u'd get two cylinders at 5k+ RPM. Also when moving off idle normally, quickly, anything but moving very slowly, the bike stalls.

-Installed FactoryPro Race kit with BMC Pod Filters for Full exhaust.
-Bike now runs on both cylinders throughout rev range but still stalls off Idle....u can feel it starting to die at that position just off idle as u slow roll on, but if u go slowly enough it gets through that spot and runs fine.

Am I lean or rich? (I would think lean, right?) How do I correct this?

Thanks,

Bryce

Xracer264 · 03-27-2006, 11:22 AM

What do you have the idle set at? On the TL I used to own I set idle at about 12-1300 RPM.

**Rev** · 03-27-2006, 11:23 AM

just set your idle higher...

Bster13 · 03-27-2006, 11:23 AM

No tach...broke that already haha.

I was thinking of adjusting the idle....the bike will idle and start fine (with some choke) but will bumping the idle speed slightly help this just off idle problem? thx.

Bster13 · 03-27-2006, 11:25 AM

ok, I'll try bumping the idle...but if I am having just off idle problems and the bike idles fine, I'm not sure if bumping the idle is going to solve this?

***Cakes206*** · 03-27-2006, 11:46 AM

Quote:

Originally Posted by Bster13

ok, I'll try bumping the idle...but if I am having just off idle problems and the bike idles fine, I'm not sure if bumping the idle is going to solve this?

Whats the idle set at now?

Was it cold outside when you were getting the back firing? The jetting/air temp might be fighting with each other. Are you 100% sure both cyl. are firing? I had somewhat of a similar issue a couple winters ago, where it would run and 5 min later it would start back firing like crazy, then stall. Ended up being that the front cyl. wasn't firing...due to flooding from the jetting/spark plug combination being off. Fixed the jetting, put the right plugs in(from a 9e to an 8e) and she purred like a

should. Had to do an oil change too because of all the unburnt fuel mixing with the oil.

High_Revs_17 · 03-27-2006, 11:54 AM

Quote:

Originally Posted by Bster13

ok, I'll try bumping the idle...but if I am having just off idle problems and the bike idles fine, I'm not sure if bumping the idle is going to solve this?

This doesn't seem to be a stunt bike so bumping the idle to make up for a fuel/air mixture and/or carb. problem isn't a great idea, unless you don't plan on keep that motor for long. If you can't fix the problem yourself, or don't know how and live in NJ call these guys, www.washingtoncycleworks.com they're a very reputable shop that'll get you back on track.

MrQuickR1 · 03-27-2006, 12:47 PM

check/replace your plugs. Could be fouling or fouled out.
Do you have a power commander? If so check the map and make sure it didn't go haywire and delete the map that was in it.
I wouldn't fuck with the idle...doesn't sound like it.

***Cakes206*** · 03-27-2006, 12:52 PM

Quote:

Originally Posted by MrQuickR6

check/replace your plugs. Could be fouling or fouled out.
Do you have a power commander? If so check the map and make sure it didn't go haywire and delete the map that was in it.
I wouldn't fuck with the idle...doesn't sound like it.

Carb'd bike, no PC.

on the plugs too.

DougZ · 03-27-2006, 02:22 PM

Well, Knucklehead, since you just did the jetting..sounds like you went too big and are running rich. I don't know where you can get that thing out to run down the road, but if you can, do this.

Get up to a good cruising speed, say 50 - 60. Roll on the trottle full bore to get going in a high gear 5th or 6th. After accelerating full throttle, roll off just a hair. If the bike speeds up when you do that, you are rich and need to go back one size on the jets. If not, the jets are fine.

SPRHK · 03-27-2006, 07:24 PM

Step 1, replace your plugs. if they are really light in color, you are running lean. If they are black and sooty, you are running rich.
Step 2, if you still have an off idle glitch, you probably need to adjust your needles.

you need to look through the directions of your jet kit. make sure you set it up right. they usually give you multiple starting points to coinside with various state of tune.(slip-on, aftermarket A.F., and so on. Another way to tell if you are lean or rich is a less-air test. Tape over 1/2 of your airbox opening. if the bike runs better, you're lean. If it runs worse, you're rich.

Roberts · 04-19-2006, 09:06 AM

Sounds like the pilot or idle jet circuit is restricted. Main circuit doesn't play a huge part within the first 1/8 to about 1/4 of the throttle opening.

jcblitz · 04-19-2006, 09:10 AM

Quote:

Originally Posted by DougZ

Well, Knucklehead, since you just did the jetting..sounds like you went too big and are running rich. I don't know where you can get that thing out to run down the road, but if you can, do this.

Get up to a good cruising speed, say 50 - 60. Roll on the trottle full bore to get going in a high gear 5th or 6th. After accelerating full throttle, roll off just a hair. If the bike speeds up when you do that, you are rich and need to go back one size on the jets. If not, the jets are fine.

changing the jets doesn't affect the idle, they're a different set. But it could indirectly affect it like others are saying, could be to rich and fouling some plugs.