Throttle hangover - how to cure it.

[kecup]

Hello to everyone,

 

a local well known shop has done a big $$$ tune-up on my 1997 1100 Sport-i only to leave the bike with an idle so low that it does not idle at all half the time, and (more bothersome) a throttle hangover. This is manifested by the RPM hanging high for some 1-2 seconds after one fully closes the throttle. This feature practically eliminates the engine braking and makes the actual brake braking interesting as well since the bike wants to run when rider would like to stop (by closing the throttle and sqeezing the brake lever). Changing gears gets a bit funky at times since the gearbox is not quite unloaded when one closes the throttle to operate the clutch and change the gear.

 

Problem is that the local experts lost the ability - according to their own words- to deal with the new (just for 15years:) guzzi's fuel management so no possible fix there. Not mentioning the trust issues after the new paint job on the bike was mysteriously (since no one knows how it happened) scratched at two places while the bike was at the shop. Which leaves me on my own, if only I'd know what to do? Tried to manipulate the throttle position sensor but it is hard without actually knowing what to do.

 

Kecup

[gstallons]

Without knowing which continent you live on, we cannot help much.... Where do you live, what kind of $$$ tune-up was and has been done, and how long has this problem(s) existed? Did this problem come about after work was performed ?

We need to know if someone has (mis)adjusted anything simple or not. You will have to go in detail about the work history or we will bounce this around all summer before helping you.

[Skeeve]

a local well known shop has done a big $$$ tune-up on my 1997 1100 Sport-i only to leave the bike with an idle so low that it does not idle at all half the time, and (more bothersome) a throttle hangover. This is manifested by the RPM hanging high for some 1-2 seconds after one fully closes the throttle. This feature practically eliminates the engine braking and makes the actual brake braking interesting as well since the bike wants to run when rider would like to stop (by closing the throttle and sqeezing the brake lever). Changing gears gets a bit funky at times since the gearbox is not quite unloaded when one closes the throttle to operate the clutch and change the gear.

 

BTDTGTTS, only w/ my SV650 (curvy, so carb'd model.) In my case, it was clear that the shop droid who was using my bike for a track day [over 400 miles on my new tires, etc.] didn't know how to ride a v-twin so purposely adjusted the idle incorrectly to get i4 engine behavior. [A host of "did wrongs" I could go into, but irrelevant to this discussion.]

 

In your case, I submit that there is an air leak somewhere leading to the inability to idle, which in turn led the droids in your shop to adjust the idle as high as they could to get it to keep ticking over. This would account for the symptomology you're experiencing. Find the intake leak & fix it, & your idle should go way high; adjust the idle to where it should be, & your proper v2 engine braking will return.

 

Just my best guess, I'm no , but it seems to me that Ockham's razor points to this as the most likely explanation.

 

Mmm, hear that? It's the sound of the customer getting bent over by an unscrupulous shop w/o so much as some Vaseline or a courtesy reach around...

[mznyc]

Yup ,sounds like it could be an air leak.Check TB boots as those tend to be a weak point.

PS This thread should be in the "Older Models" section

[kecup]

Without knowing which continent you live on, we cannot help much.... Where do you live, what kind of $$$ tune-up was and has been done, and how long has this problem(s) existed? Did this problem come about after work was performed ?

We need to know if someone has (mis)adjusted anything simple or not. You will have to go in detail about the work history or we will bounce this around all summer before helping you.

 

I live in Los Angeles, the cylinder heads have been rebuilt with new valves installed and the bike was tuned up afterwards. The throttle position sensor has been adjusted - they told me they have cleaned it and repositioned it. The problem appeared AFTER the work has been done. Thanks for trying to help.

[gstallons]

I am going to help. I just needed to know some things first. Can you pm your cell # and I will call you around 8 pm cst. I am going out because this is the first good day to ride !

[kecup]

I am going to help. I just needed to know some things first. Can you pm your cell # and I will call you around 8 pm cst. I am going out because this is the first good day to ride !

 

PM sent, thank you.

[kecup]

Yup ,sounds like it could be an air leak.Check TB boots as those tend to be a weak point.

PS This thread should be in the "Older Models" section

 

 

Thanks for advice. If there is an airleak this would be permanent, correct? Meaning that the RPMs stays up all the time after I close the throttle. My problem is more time restricted, when you close the throttle at, say 3000RPM, it stays up for 1-2 seconds before slowly dropping to the idle. The bad idling may be just because the local expert who tuned up the bike set the idle to 800RPM. This guzzi just does not idle reliably at less than 1000RPM, cold or hot.

[gstallons]

Is there any way you can post a video of this on youtube so we can hear/see this action taking place. I am not sure if it is not the throttle hanging. I fell asleep last night is the reason I didn't call you back. How did your test ride turn out?

[kecup]

Is there any way you can post a video of this on youtube so we can hear/see this action taking place. I am not sure if it is not the throttle hanging. I fell asleep last night is the reason I didn't call you back. How did your test ride turn out?

 

I checked thoroughly if there is any throttle hanging but it seems not. The throttle snap closes and the bike holds the RPM and then slowly drops them long after the throttle mechanism at the TBs is fully closed. The problem gets worse when the bike runs hot. When one idles the bike at higher RPMs -so the engine gets hot, and then opens throttle to say 3000RPM, the bike holds that RPM all the time after the throttle is fully closed. When you turn off the engine and start again, the RPM respond to the throttle closing but with the usuall 2-3seconds lag. Think I need someone to tune the bike, what a crap.

 

Forgot to mention - I have power commander installed. I am not sure how this effect things but surely the local "expert" knew this when he played with the bike.

[Skeeve]

 

Forgot to mention - I have power commander installed. I am not sure how this effect things but surely the local "expert" knew this when he played with the bike.

 

1st step: disconnect the PC; they've been known to go haywire, leading to all sorts of unusual behaviour that cannot be properly diagnosed as long as it's in the circuit. So the correct modus operandi for resolving your issue is isolate (remove) the Power Commander, make certain the bike runs right w/o it, then splice the PC back in & make certain it is functioning correctly.

 

If you remove the PC and your problem goes away, well, you know where the problem lies!

[docc]

Good advice so far. With the Sport-i so similar to the V11 variants, I think we're in the right forum for this discussion. We might could all learn a thing or two from it.

 

You say when the bike is off, the throttle snaps back closed? No chance the cable or linkage is rubbing (have a look)?

[gstallons]

kecup,

Pacify us and disconnect the throttle cable at the left throttle body. Start the bike and blip the throttle on the portion of the throttle body where the inner cable was attached. It should return to idle immediately. If this "fixes" it, look at the throttle barrel to see if it works on the handle bar freely. It shoul be binding.If it is loosen the two Allen head screws and get things back in place.

There is no way the computer can keep the rpm up and cause this problem. Even if they screwed up the tps it should still work ok.

[Kiwi_Roy]

I might be out to lunch but I just went through the same symptoms with a Honda Goldwing the revs were several seconds behind the throttle.

It turned out the slow running jets were blocked and the idle adjustment had been wound in so it was idling on the main jet. After cleaning out the idle jets and backing off the throttle stops there is no comparison.

 

Now I know your bike is injected and mine is carbs but I thought it might trigger a thought like running way too rich. idle screws too far open or something similar.

Roy