If I set idle to spec RPM's won't come down when shifting

[WiVR]

Anybody run into this?

 

If I set the idle to 950-1000 with the adjuster screw, the RPMS are very slow to come back down after revving. When I ride, I shift and the RPMs stay prettty much where they were when I pulled in the clutch.

 

Running good otherwise.

[Rocket]

Anybody run into this?

 

If I set the idle to 950-1000 with the adjuster screw, the RPMS are very slow to come back down after revving. When I ride, I shift and the RPMs stay prettty much where they were when I pulled in the clutch.

 

Running good otherwise.

 

Sounds like the throttle cables need a good lubing (at the least). To do a good job of it & get at all the cables with a cable lubing tool, the left fairing will need to come off, to check & lube all the cables at the junction block.

[WiVR]

I'm sure they could use a lube.

 

What's weird is if I back the adjuster by the left side carbs out so it does not touch the cable, my idle is at about 400 but the rpms come back down just fine while riding or revving. Just hard to keep running at that low of an idle.

 

As soon as I turn in the adjuster to increase the idle, the rpms "float" down.

[Marcarl]

Try doing a good carb sync, often that will clear the problem you speak of. I'm not saying not to grease the cables, they do need it periodically, but it sounds to me like carb sync time.

[GeorgeS]

Also. the throttle plates on each carb, each end of their shaft's, use some light lubrication.

 

And lube all the moveing parts of all of the Throttle linkage assembly parts between all 4 carbs.

 

Also, listion carefully for any vaccume leaks.

 

But you might have to do a Re-Sync job.

[gscbertrand]

I just learned of a product called Jig-a-loo that people on a different motorcycle forum are giving very good results to. The products are available at lots of different stores like Zellars and Home Hardware... if your interested try going

www.jigaloo.com and check things out.

[BradT]

Dirty Carbs, they need a cleaning. Try some seafoam for a few tanks and it should get better assuming cables are not the problem.

 

Had this happen once before, cleaning the carbs did the trick

 

BRad

[Condor]

Try doing a good carb sync, often that will clear the problem you speak of. I'm not saying not to grease the cables, they do need it periodically, but it sounds to me like carb sync time.

 

[jasonm.]

simple question. whether running or not. But easier to hear when not. Do you hear the click at the carbs when you open the throttle then let go? The click is the idle stop screw contacting the throttle stop of the carbs. No click= bad(frayed cable) or needing a good lubing or adjusting to proper specs. Note: the Venture Cruise makes the lower cables are difficult to lube.With the Cruise design- There are 4 cables, 2 upper and 2 lower . The lower cables do fray. Mine went...I caught mine when only half the strands were there. Also there is both an upper and lower adjustment.

[WiVR]

The throttle snaps back without hesitation. Makes a sharp "click" when it bottoms. Checked while bike was off.

[dray]

my Vstar started to do that and i found it was a carb boot had poped off from the airbox just a thought you my want to look it over it would idle down but it took a lot longer than it should have 5+ seconds

[WiVR]

Boots are good. Looked at butterflys with the engine off and they snap back with the grip. If I pull in the clutch at 5k to shift RPM's stay at 5K until I let off the clutch. If I just hold in the clutch they float slooowwly back down.

[Marcarl]

Boots are good. Looked at butterflys with the engine off and they snap back with the grip. If I pull in the clutch at 5k to shift RPM's stay at 5K until I let off the clutch. If I just hold in the clutch they float slooowwly back down.

Have you done a carb sync yet? don't go by the throttle plates and just looking at them. I would say that you have one carb, a way out of sync.

[WiVR]

Carb synch done. Idle, 2000 and 3000. Very close.

[Marcarl]

Carb synch done. Idle, 2000 and 3000. Very close.

I don't quite understand this, but if I got it right you sync'd at 2000 rpm? You need to do it at 900 rpm.

[WiVR]

They are synched perfectly at 950. I also checked them at 2000 and 3000 and they are pretty close.

 

If I crank the idle adjuster knob all the way out, the idle will drop to about 400 and eventually die. But if I ride the bike like that, all is great. Just have to keep the grip twisted a little when I stop.

 

Only have the problem with the RPM slow drop down when I adjust the idle to 900/1000.

 

So I can get good idle but the RPMs wont come down (or very slowly) when shifting or a lousy idle and normal RPM behavior when shifting.

 

Revs fine in neutral. RPMs drop normally.

[GeorgeS]

Have you run a can of SEA-FOAM, or a good fuel injector cleaner ?

 

Also, did you pull the air cleaner and watch the pistons in each carb at idle, make sure they are all dancing back and forth.

 

Did you open the Drain line on each carb and drain the bowls, let fuel pump flush each bowl, one at a time ??

 

Have you ever completly drained the fuel tank on this bike. Good idea, to completly drain it, and start with All new fuel. Might be some crud and water in bottom of you tank.

 

A few witch hunt items, ???

[WiVR]

Like squeezing a ballon. Take care of one thing and another pops up.

 

Since I picked this up a few weeks ago, I have drained the tank, installed new diaphragms, soaked the carbs for seven straight days with seafoam straight from the can through the fuel pump, drained and flushed the carbs at least 10 times, changed the fuel filter, run 3 tanks of gas through with 1 can seafoam per tank, changed oil and filter, soldered the pins on the class controller and cleaned out the rear master bleeder hole. I know there's still more to do but I have spent more time working than riding. Weather is finally getting nice in WI and would like to get these couple issues resolved if poss.

 

Thanks for all the help. This is a great forum.

[GeorgeS]

Boy, I'm out of ideas on this one.

 

Just one more?? Does your Throttle " Pull " cable have at least 1/16 to 1/8 inch of Slack ?? before the linkage on the L Fwd Carb starts to move off idle ?

[WiVR]

It does. I adjusted that before I synched the carbs. I have kept a small amount of slack in the cable regardless of the idle adjustment.

 

I don't know what else to adjust/inspect/clean.

[Marcarl]

Just above the carbs on the left hand side, there is a cable coming from the top, it's the throttle pull cable, it has an adjuster on it, takes 2 10 mil wrenches, the maesurement from the last thread to the larger part of the adjuster (so the setting nut is not included) is .59 inches or 10 mil. Start by making sure that that is correct, then there is an adjuster at the top by the handle bar, you now adjust this one until you have 1\16 in play or so, or try to adjust so that things work well. Sometimes if you have worked on the handlebars, you may have twisted the cables and so they tie up on you. Take a look there and make sure that they are not binding up.

Keep coming with your comments,, we'll get it fixed somehow. Something is going to show up,,, it just has to,, there is no other way.

[GeorgeS]

Just above the carbs on the left hand side, there is a cable coming from the top, it's the throttle pull cable, it has an adjuster on it, takes 2 10 mil wrenches, the maesurement from the last thread to the larger part of the adjuster (so the setting nut is not included) is .59 inches or 10 mil. Start by making sure that that is correct, then there is an adjuster at the top by the handle bar, you now adjust this one until you have 1\16 in play or so, or try to adjust so that things work well. Sometimes if you have worked on the handlebars, you may have twisted the cables and so they tie up on you. Take a look there and make sure that they are not binding up.

Keep coming with your comments,, we'll get it fixed somehow. Something is going to show up,,, it just has to,, there is no other way.

 

Yes. Check to see if handle bar movement is haveing some effect on the Pull cable.

[mbrood]

A lean fuel condition can cause the rpm to be sluggish to drop... have you pulled the plugs to check the color is nice and light brown (not white and dusty.) ?

 

You have made some big changes... time to check the plugs and see how she's running.

[GeorgeS]

How about a vaccume leak, where the Intake Manifolds, mount to the Cylinder heads ??

 

I have heard of a few folks, removed them and replaced the O-Rings, and still have vaccume leaks,

 

Next fix, was remove them again, and apply gasket sealant.

[jasonm.]

WiVR is correct. The correct way is to sync (check) them at more than just idle. I also check at 3000. Reason for this is because of the linkages on the V4. You don't ride @idle.