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California 1400 hanging throttle

Let me first state that overall I'm very happy with my 2014 Ca 1400 Touring. However the 2 second delay in throttle return is driving me nuts. I've been riding motorcycles for over 50 years and this is the first one that has a delay before the revs reduce after letting up on the throttle. It is also the first one with throttle by wire. I was starting to think that it was simply a symptom of throttle by wire but have since bought a Ducati with throttle by wire and it behaves normal. This is only noticeable when shifting, especially up shifting as it seems like I'm not letting up on the throttle to shift with an annoying rev between the gears. Downshift is not quite as bothersome since I usually rev match and blip the throttle anyways. Anyone else have this problem? Is there a fix? I've the thread on hanging throttle but this seems different, thankfully not as bad but still annoying.
 
Curt what "Engine Mapping" is showing on the instrument panel?
I tried PIOGGIA once, throttle response was definitely slower. So slow I think Guzzi should change the label to "vecchio bislacco" (geezer). Changed to Veloce within 5 miles. Before I had 50 miles on the odometer. Throttle response, opening and shutting, much more satisfying.

Installed the full GT-Rx fuel mod package, at around 4K miles, transformed the throttle response from satisfying to awesome.
 
Curt what "Engine Mapping" is showing on the instrument panel?
I tried PIOGGIA once, throttle response was definitely slower. So slow I think Guzzi should change the label to "vecchio bislacco" (geezer). Changed to Veloce within 5 miles. Before I had 50 miles on the odometer. Throttle response, opening and shutting, much more satisfying.

Installed the full GT-Rx fuel mod package, at around 4K miles, transformed the throttle response from satisfying to awesome.
I usually run in Veloce but occasionally touring. Never even tried Pioggia. Ha ha probably never will. Seems the GT-Rx fuel mod might be a good mod even if it doesn't fix it. Actually I'm considering his whole exhaust system to get rid of the tinny sounding exhaust shields anyways. Thanks for your input. Decisions, decisions ......
 
Curt, 'fraid Run in Veloce mode, and GT-Rx fuel mod was pretty much all I have to offer for slow throttle response. I'm contemplating Todd SS headers too, mostly due to bluing of the stock headers. I prefer the golden tone test SS headers usually take on.

The tinny heat shield rattle was solved with new OEM washers and a dab of white locktite. I don't anticipate removing the heat shields any time soon.
 
Hope you're right about the fuel mods Blakbird. I'm sitting at the sandwich shop next door to Todds shop while Todd is mounting his whole stainless exhaust system along with the fuel mods. Should be done in an hour. It's going to be a fun ride home!
 
Were you told why they thought the clutch was slipping?
The best guess was there was some water in the hydraulic fluid that would boil in extreme heat and pressurize the clutch line, partially disengaging the clutch. I have heard of similar things happening on the brake lines of race bikes due to extreme brake disc heating. I have never opened the clutch master cylinder, and have never pressure washed the bike, so it's hard to say how water got in there. There just aren't any other logical explanations. MG replaced the master cylinder and covered all the labor and testing. Just brought the bike home today, so I'll get a chance to ride it this weekend to make sure things are fixed. They also said the clutch switch checked out good, so I'll check the 3K engine breaking issue when I go down my favorite long hill.
 
Hope you're right about the fuel mods Blakbird. I'm sitting at the sandwich shop next door to Todds shop while Todd is mounting his whole stainless exhaust system along with the fuel mods. Should be done in an hour. It's going to be a fun ride home!

Well Curt, how's it hanging ?
 
Just to follow up on my clutch issue--I've put about 500 miles on the bike with no further clutch slippage. I don't know if they actually replaced the clutch switch when they changed the clutch master cylinder, but I've noticed improvement in the hanging throttle and engine braking issues that I've commented on before. Now when I come to a stop in gear with the clutch in, the revs drop to 1200-1300 right away--I don't have to shift into neutral and let the clutch out now. Also, on long downhills, the loss of engine braking at 3000 rpm is significantly better. I still notice a reduction in engine braking when revs drop to 3K, but I can still get some engine braking and deceleration below that. It used to feel like it was getting gas to keep it at 3K with the throttle rolled all the way off.
 
Hi guys, thought I'd pass on my experiences on this & might save you some time & expense. But sorry, as yet no cure. My 3 year old 1400 touring (6.5k miles) suffers badly with the hanging throttle issue. The bike doesn't need to be particularly hot before behaving abnormally, once warm & running in cool ambient temperatures (50*f) the revs will hang. The symptoms: Decelerating on a closed throttle & with 100% engine braking above 3000 rpm once the revs drop below 3k, power (ie fuel) will come back in & the revs will either decrease very slowly, or just hang @3k until the throttle is blipped or the engine killed. The bike also hesitates while accelerating from low revs frequently.
Before anyone suggests Todds fuelling mods, I already have them & while the overall engine response is much improved they haven't helped this issue. This is not a problem with the fuel table.
All specs checkout as normal in Guzzdiag against the references in the manual & the throttle reset/learning have been done numerous times.
So far I've tried the following to attempt a cure: Replaced the clutch switch. Made no difference. I know some have reported success with this but to be honest I had my doubts. The switch only has two positions (in or out) & it's function can be checked in software. I replaced it anyway, to no avail.
Replaced the MAP (manifold absolute pressure) sensor. The above symptoms can replicate those of a failing pressure sensor but sadly it made no difference.
Removed & cleaned the throttle body, checked for air leaks & again no improvement.
I still think this is a manifold pressure issue rather than one of fueling or throttle synchronisation & still hope to find a resolution.
I love this bike, but this glitch makes riding it at anything other than cruising speeds a frustrating experience.
Jon
hello, just joined .. not sure how system works .. i have a 2014 california (bought new) .. witnessing the same throttle problem .. i always thought it was a built in feature to keep the throttle plate open to burn off HC's .. mid 70's cars did this by way of a damper on carburetor (EPA & SMOG .. if not .. why is there not a re-call by moto guzzi .. miss not having the back pressure before going into a turn as my other bikes have .. i just finished doing a 6200 mile service on bike .. valves were out of adjustment more than i thought they should be .. noticed someone wrote they felt miss adjustments of valves may be the cause of the problem .. have not ridden the bike since .. will post again after some test rides .. ride safe and be safe .. old-guy
 
Just got back from a 1 hr ride after doing the 'moaning whale fix' and no difference in the hanging throttle and in fact it seemed to idle higher than before (now at 3,000 rpm).

What I did notice I can do to stop it from happening is instead of down-shifting as you come to a stop as per normal procedure (ie. let the clutch lever back out after each downshift), is just to stay IN GEAR until the rpm's drop to 2,000 or below and then pull the clutch lever in, keep it in, and down shift with your foot all the way to 1st gear.

I never had the hanging throttle happen when I did this. Letting the revs climb down while in gear seems to work so far ...
 
Thought I'd chime in on the throttle issue, I just had the 20K service performed, a few days later I hit the road travelling from RI to FL via the Smoky's. I'm currently on my 4th day of the trip and the bike has run great. To rewind a bit, I had one throttle issue right after I purchased the bike when temps dipped into the 30's that was with 500 or so miles on the bike, I was at the bottom of an exit ramp and due to the weather being in the 30's my hands were freezing so I thought I had a death grip on the throttle, but after a couple attempts to bring the idle down from around 2500 / 3000 I had to shut the bike off and restart to reset.

At the 10K service I had the dealer check it out and they said it's not a know issue and they could find nothing wrong with the bike. Now, fast forward to 2017 and 12,000 miles later there has been no repeat throttle issue until tonight. I started the bike after dinner and the throttle went almost to red line. I immediately turned the bike off and restarted and everything was fine. I've got about 600 more miles to go to my final destination and hopefully this bike doesn't strand me. I hate to say it, but in the south-land Guzzi dealers are few and far between. My only option would be to roll it into a u Haul and take it to a dealer somewhere.

I'm going to try and stay positive and hope its just a fluke. If I do get stranded out here I'll most certainly trade it in at my earliest opportunity. Each time there was an issue the weather's been very cold, I don't believe its a cable or throttle body issue as shutting the bike down and restarting almost immediately remedies the issue. I'll post once I see what happens tomorrow on the road...
 
I bought an extremely low mileage 2015 Tour (270 miles) and discovered it had an idle problem. Everything was normal when it was cold and as it started to warm up. After that I would get the notorious hanging throttle @ 3,000rpm. We can all rest assured that Moto Guzzi didn’t design a motorcycle so that the idle would hang, nor did their test riders just miss that fact. I started reading all the posts to see if there was any info on this. Turns out there are many complaints like this. That's important to note because, as this was under warranty, the dealer, Piaggio USA, and Moto Guzzi Italy were all eventually involved. ALL of them claimed they had never heard of this before (even though it is easy to verify there were complaints back to model year 2014). As we all know, going to the internet is a real iffy way to fix anything as people who don't know what they are talking about freely diagnose your problem and tell you what to do even though they have never seen your bike or had this problem themselves. At the next level come the well intentioned folks that that have exactly the right cure if this problem was occurring on their old 1966 Chevy. Then we have the totally frustrated owner who has spent a lot of money on what he thinks is a superb motorcycle with just this one problem that greatly affects rideability and, apparently, with no real solution. Just guesses and shots in the dark about changing this, adjusting that, tell the dealer to do this, replacing something else or adding some aftermarket part or system that might be great but was never designed or intended to cure this particular problem. When it's all over they still can't say what caused the problem. Remember, we want to correct not cover up the problem. I found a very conscientious dealer that worked on it for almost two months after doing a fresh 1000 km service. Here is the result:

When there is warranty involved, it has to be addressed the way the factory wants the dealer to approach it. For instance even if he is right, an experienced MG mechanic can't go directly to what he might suspect the problem is. This led us to days and days of "check this reading, measure this, look for this, adjust that” and so on; with a test ride after each change or check. Interestingly this was almost all electrical in nature. (this is the same assumption driving most of the posts you see) At one point, the bikes running engine was linked to the mechanic's laptop to their WiFi to the internet through Piaggio USA and then direct to a mechanic in Mandello Del Lario. Once they had exhausted all other possibilities, the dealer was then allowed to go into the mechanical phase. Mechanical checks of lash, compression and leak-down were fine but the computer diagnostics of the left cylinder were still coming in oddly different than the readings on the right. Italy sent a completely assembled new head for the left cylinder (887163). When the dealer pulled the left head to start the install, they found the problem;

One of the two exhaust valves was not quite concentric with the seat. Because this is a well-designed and finely integrated engine, a LOT of things effect or are affected by multiple other components. Most all of the other “cures” that you see posted could be affected by this also. Heat changes the valve lash, the air temp sensing, the idle, and the mixture. Then the computer tries to compensate idle. It is trying to adjust one idle speed with two cylinders that are no longer balanced using a single throttle body for both cylinders and measuring the results with two separate lambda probes. It is getting input from anything that has any information on temp, vacuum, clutch position, O2 sensors, mapping, fueling and idle speed. To be sure, any of those extra items can make things worse if they are also incorrect but even when their replacement results in a change it may or may not be an improvement, but it is not a cure. This bike has now been extensively test ridden and is now pronounced cured by the dealer. I’m very confident they are right. I see no hint of the original problem. I can see a huge change and it does, indeed, seem totally correct now. For my own final pronouncement, after winter breaks, I still want to push the motor into temperature and altitude scenarios where I’ve never had it before. I doubt I’ll see any problems as they were testing it at temps and speed where the problem was very easily duplicated before and it is now gone. I just want that extra assurance for myself before the warranty expires. I am also posting a picture of the head with the two exhaust valves removed so you can see marks and coloring in that area. There have been a lot of hands on this part but you can still get a good idea of the situation. I’m sure Moto Guzzi had a pretty good idea of what this problem was but there were other possibilities in the head and their decision to replace the entire head was an instant success. If you are no longer under warranty, a good precise valve job might fix yours. Just consider the possibility that yours might be a different head problem, like a crack. With warranty it is cheaper for the factory to send you a head ready to go. I’m posting this now because I’ve seen nothing definitive on cause and there may be folks out there still as frustrated as I was. Once you have this motorcycle running like it was designed to, THEN you can start changing the aftermarket stuff from air cleaner to sensors to programs to fueling to exhaust or whatever makes your fun meter go up.

You’ll be much happier when you start applying your modifications on top of what seems to be a really great motorcycle with one problem ……… that can be fixed!

What a great machine!

IMG 3129
 
A quick status update on the hanging throttle issue on my bike. Since I had the clutch slippage issue fixed, I have put 3000 miles on the bike without any significant hanging throttle or loss of engine breaking at 3K on deceleration. However, twice in the last 2 months the revs have hung up at 3-4K rpm when the clutch was pulled in. Both times it was after riding from Phoenix (1200 ft) up towards Prescott (6-7000 feet). Breaking in gear to drop the revs solves the immediate problem. If I stop and turn the bike off, the problem seems to go away, and I don't experience it again when descending back down the hill towards Phoenix. Sounds like an atmospheric pressure sensor problem that gets reset when the bike is turned off. Anyone else notice an altitude related component to their hanging throttle issue?
 
Fascinating post MotorGoose. I came to the conclusion this problem must be something mechanical. Having replaced or substituted virtually every electrical component to no avail & invested in Todd's fueling package the problem still persists. Before pulling the heads I'll do a leakdown test. I have a tester but haven't got round to modifying a spark plug enable fitment.

The photo shows an area of lighter colour between the exhaust valves, does this indicate where the valve wasn't sealing properly?

Thank you very much for the information.



Jon
 
You’ll be much happier when you start applying your modifications on top of what seems to be a really great motorcycle with one problem ……… that can be fixed! What a great machine!
As already stated, great first post, and thanks for taking the time to document it here. This is root of this website for data like this to help/direct informed owners. Yes, I also too often hear "never heard of this" from those that have the power to fix things and keep a customer happy. I'll be doing a compression test on all I see with a high idle problem from here on out.
 
Thanks guys. The dealer did all the work, not me. But I did the reporting. Just a heads up (no pun intended); we did a compression test and leak down on mine and everything was within parameters. It did NOT indicate a problem. One of the predominate problems with this issue that you see in the posts is that it happens at higher heat levels. With a very slight misalignment, the valves seat well enough for the engine to run cold or maybe even warm because it is running a richer mixture during these phases. The hanging shows up after the engine is thoroughly warmed up or hot. My belief (just my opinion) is the heat is a real important part of this equation. Your cylinders are aluminum. Your valve train is almost all steel. They do not heat up, expand, or dissipate heat at the same rate. That means that each system grows at a different rate. That's the reason you need valve lash in the first place. If I have a valve that is marginal in its fit/seal and then the motor starts to heat, the lash is reduced and more of the cam lift is transferred to the valve itself. All it takes is a tiny change and now the valve starts to allow a tiny amount of the charge to revert. I'm pretty sure this reversion is what the sensors are picking up and sending all the confusing info to the computer. The more you make it work; high temps, heavy traffic, pulling grades, heavy loads or throttle application, the sooner it shows up. When you stop and turn it off to reset or get it in the shop to measure, the temp differential between the steel and the aluminum has begun to equalize.
In the photo (sorry, it's the only one I got) look at the 7:00 to 8:00 position on the left hand exhaust valve as it is in the picture. You may be able to see where the shiny portion of the seat face (where the valve has been making contact) reduces to a knife edge.
If somebody else runs into this, I would be curious to hear if it is on the left cylinder as well.
 
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