Idle problems

[spydah]

I'm having a strange idle problem on the sv650. It was running crappy and rich so I took the carbs apart, blew everything out with compressed air, put it all back together. I also drained the gas and put some fresh gas in. Whatever was in there was at minimum borderline junk.

Now its back together and it seems smoother, but now there is an idle problem. It idles fine around 1300 rpms until it goes into high rpms, after coming off throttle it hangs around 3000 rpms for about 8 to 10 seconds before slowing down to normal idle again.

Things I've checked:

1. Cable adjustment
2. No loose hoses
3. Butterfly arm makes solid contact with idle adjust screw
4. disconnected the wire on the electronic thing on the carb (made no difference),

Any thoughts?

[OreoGaborio]

Hanging RPM's is usually a vacuum leak. Check all the boots & seals.

[spydah]

Hmm, I had a hunch it might be vacum related as everything physical seems kosher. I'll give that a shot. Thanks!

[GixerJockey]

Air leak. You probably didn't get the intake boots back on there securely after servicing the carbs. (the same thing happened to Oxx on his GF's blue SV at the last TTD)

Do you know how to check for air leaks?

Prop the tank. Start the bike and let it idle down. LIGHTLY spray some carb clean around the intake boots. One carb at a time. If the RPMs go up, you found your air leak. Basically, the combustable carb clean will provide extra fuel through the leak. If it's being sucked into the intake through a leak, the RPMs will raise.

[BostonSVkid]

Air leak. You probably didn't get the intake boots back on there securely after servicing the carbs. (the same thing happened to Oxx on his GF's blue SV at the last TTD)

Do you know how to check for air leaks?

Prop the tank. Start the bike and let it idle down. LIGHTLY spray some carb clean around the intake boots. One carb at a time. If the RPMs go up, you found your air leak. Basically, the combustable carb clean will provide extra fuel through the leak. If it's being sucked into the intake through a leak, the RPMs will raise.

+1 this is how i found my leak on my SV. i was also running rich at the time too.

[spydah]

I just totally yanked it apart and put it all back together being sure to properly seat the boots, and it still had the problem. Maybe the boots are bad? I'll try to carb cleaner trick. They shouldn't be bad, this thing is so clean it could be new. Its only got 1k miles on the odometer.

This is just dumb, there are only 3 potential places where air could get in, two of which are the boots, then the other is the vac line to the fuel valve. How come after taking it apart once it turns to crap?!?!?!

[spydah]

How do you get at the front cyl intake? That looks like a challenge. I'll have to make sure I buy the still with the hose.

[OreoGaborio]

or the throttle plate shaft seals... that's what were gone on Jenni's GS.

[GixerJockey]

How do you get at the front cyl intake? That looks like a challenge. I'll have to make sure I buy the still with the hose.

The same way you got to the carb to clean it. The intake boot is inbetween the carb and the motor...

[GixerJockey]

I just totally yanked it apart and put it all back together being sure to properly seat the boots, and it still had the problem. :

So did Oxx... And Seige was helping him get it back together. That's TWO MMI graduates working on the thing and an air leak still got past them.

Do the leak test I described before you do anything else. I'm almost sure you will locate the issue that way.

[Origin]

I think I have the same problem in my YZF600r, Very similar symptoms...and im not very mechanically savy...if i do the test you described to him, what would my next move be? would it be repairable or do i need to replace them.

[GixerJockey]

if i do the test you described to him, what would my next move be? .

Light the bike on fire... Watch it burn for a little while... Come see me and buy a Suzuki...

[Origin]

Light the bike on fire... Watch it burn for a little while... Come see me and buy a Suzuki...

Man, you have no friggin clue......

954-Electrical problems up the ass...There is a little gremlin in there just waiting for me to replace my regulator and then he slices a wire.

yamaha-The little fucker jumped into the yamaha now that ive been riding that...He slices a whole in my cover so its now leaking oil, and also sliced another whole somewhere inside the engine that is pissing out oil like a friggin racehorse.

I can not wait to unload these friggin bikes somehow and get my hands on a new one....mmmmmmmmmmmm warrenty

[TLRMan]

sync being off can cause it too....

[gsxr1000babe]

Have you checked the throttle body boot.. My boyfriend had pretty much the same problem on his tlr and the throttle body boot popped out and it cause a really high idle once he put it back into place it was fine...

[OreoGaborio]

Yer not just a pretty face, I see.... The carbs are the throttle bodies on carbureted bikes.

[rebelpacket]

sync being off can cause it too....

+1. Spent the better part of two weeks chasing down an air leak, only to find that the carb's we're way off from eachother, and the idle was too high.

Make one from a yard-stick, once 8-10ft peice of clear plastic tubing, and some 90w gear oil.

[spydah]

+1. Spent the better part of two weeks chasing down an air leak, only to find that the carb's we're way off from eachother, and the idle was too high.

Make one from a yard-stick, once 8-10ft peice of clear plastic tubing, and some 90w gear oil.

Holly MacGuyver!

This thing? $1.55 Carb Sync Tool by Marty Ignazito I guess that could work.

[rebelpacket]

Its not any motion-pro tool by any means, and many people may cringe at the thought, however its worked great for me. Make sure you get enough tubing so you can stand the yard-stick (I clamp it to my bench) straight up and down to get a good level reading.

Carolyn wrote up (in detail) the procedure, and a modification to make it easier in the future here:
bluepoof bikes - suzuki sv650s carb sync

She uses vacuum gauges, which I've tried as well, but don't find to be as precise or reliable as the tubing method. Your mileage may vary.

You can statically sync them as well, but I don't recommend it.

[gsxr1000babe]

Yer not just a pretty face, I see.... The carbs are the throttle bodies on carbureted bikes.

Lol I didn't know that haha Well now i do Thanks...

[TLRMan]

Its not any motion-pro tool by any means, and many people may cringe at the thought, however its worked great for me. Make sure you get enough tubing so you can stand the yard-stick (I clamp it to my bench) straight up and down to get a good level reading.

Carolyn wrote up (in detail) the procedure, and a modification to make it easier in the future here:
bluepoof bikes - suzuki sv650s carb sync

She uses vacuum gauges, which I've tried as well, but don't find to be as precise or reliable as the tubing method. Your mileage may vary.

You can statically sync them as well, but I don't recommend it.

I picked up the Morgan unit, no more mercury, and they work the balls...
But the yardstick method works well, just make sure you have both hoses hooked up before you start the bike!

[spydah]

The carb cleaner spray trick revealed nothing. Seemed to be pretty airtite. I made the trek down to home depot and got the stuff to make the MacGuyver tester. I'll give it a shot this evening.

[spydah]

I got the MacGuyver tester working and got everything nice and synced. It was significantly off. But the damned problem still has not gone away. I've checled for leakes like 10 times with the carb cleaner trick and idle does not change.

I sprayed a little cleaner directly into the intake to see what the idle change would be like. On the front carb it jumped up as expected. Doing the same on the rear carb stalled the bike. I'm spreaying the same amount in each carb and every time it dies. Why would they behave differently? Could this be indicative of a problem with the rear carb?