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Advice Needed - Low idle/stalling


angrygirafe

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Hey all. Bit of a problem. About a month ago, I dropped my 2016 off for service with 50k miles. Asked for a full service with valve adjustment, and asked them to look into my neutral indicator, which was failing to work about 10% of the time. Okay, sure. 
 

Picked it up a couple days later, tech remarks were that intake valves were good, most exhaust valves were loose, the battery is on its way out, and my clutch is super noisy. Okay, great. Didn’t care about the clutch; it’s always been noisy. 
 

For the next two days on my commute, after the bike got warmed up, the idle would be low when in neutral at stops, and once it stalled on me. Called the shop and told them and they said to bring it back. On the way back to the shop, it had the same weak idle problems, and revving it at one light to keep it from stalling, it hung at about 2k rpms.  Dropped it off and told the tech. They said they’d look into it in a couple days. 
 

Days go by. Get a text saying the bike runs fine, they can’t duplicate the problem. Text back instructions to go ride for twenty minutes, and then let it idle and observe it. I call and leave a voicemail saying the same thing because I didn’t get a response. Almost a week goes by and no response.

 

 I call for an update. Leave a voicemail. Call the next day. They say they still can’t duplicate the problem. I say I’ll be there the next day to demonstrate it. 
 

I show up, hop on the bike, and go ride a few miles. Stop and fill it up. Fire it back up and it’s immediately a weak idle and then stalls. The whole way back I have to give it throttle when idling to keep it from dying. Get back, and it stalls as I coast into the lot. 
 

I go find the shop manager, he grabs a tech and we come out. I described what happened, fire it up, and it idles fine. After a minute, it just dies without warning. I suspect that was related to the neutral switch problems. They say they’ll get it figured out. 
 

Get a text the next day the neutral switch is shorting. I tell them to replace it, and ask if that could also cause a weak idle. They say yes. Days go by. 
 

I got a text it was done, and managed to get there before closing, but enough time for a test ride. Fires up fine, and for 15 minutes, no problem. But after it’s warmed up, at a few light, it idles weak, like 500 rpm. Doesn’t stall, and doesn’t do it every time, but it’s definitely the same problem. 
 

My question: how likely is this related to the valves being off, or the throttle body sync being off? Does it sound like it would be damaging to keep riding it until a) I recover some of my 1600$, and b) get to a different shop to look at it?

 

Thanks for reading. Been a frustrating month. It’s starting to remind me of my Triumph 🤮

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Shim under bucket valves "in particular exhausts" going loose is almost unheard of. Did they provide the previous to new clearances on the paperwork and what all else they did? If it ran fine before they worked on it......very obvious they screwed something up.

Edited by Ride365
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This sounds very similar to a R1 I had to diagnose and it turned out someone had mixed up the plugs on the map sensor and the atmospheric pressure sensor. Might well be the same issue, all happened when a previous shop had done the valves as well. I’d get the fuel pressure tested too, as well as checking for water in the fuel.

Edited by Buggy Nate
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It's sad when you take it to the "pros" that happens. Then they have the audacity to charge $1600 for it.

Improper valve adjustmet, sync, and reassembly all can cause these problems. 

short of you redoing all the above I don't know what's wrong.

Very sad.

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1 hour ago, Ride365 said:

Shim under bucket valves "in particular exhausts" going loose is almost unheard of. Did they provide the previous to new clearances on the paperwork and what all else they did? If it ran fine before they worked on it......very obvious they screwed something up.

I do have some docs including a rough sketch with some measurements from the tech. I'll try and dig it up after work, but yes I was surprised to hear "loose" after literally everyone here has always had tight exhaust valves. Scares me he got it backwards and now they're super ultra mega tight.

1 hour ago, Buggy Nate said:

This sounds very similar to a R1 I had to diagnose and it turned out someone had mixed up the plugs on the map sensor and the atmospheric pressure sensor. Might well be the same issue, all happened when a previous shop had done the valves as well. I’d get the fuel pressure tested too, as well as checking for water in the fuel.

That sounds interesting. Maybe something I can check myself?

28 minutes ago, peteinpa said:

It's sad when you take it to the "pros" that happens. Then they have the audacity to charge $1600 for it.

Improper valve adjustmet, sync, and reassembly all can cause these problems. 

short of you redoing all the above I don't know what's wrong.

Very sad.

Yeah, I tried this shop (licensed dealer) because it was closer than the one I've used here in the past and had solid reviews. Still relatively new to Phoenix, so I haven't needed a lot of service done aside from oil which I do myself. Now I'm going to end up taking it to the smaller, father shop to have them verify/fix the work, and fight these guys to get some money back. Kinda wish I'd just bought a service manual and the few tools I don't already have and done it myself. But then, I don't have the time, which is why I paid them in the first place. Ugh.

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Definitely buying a service manual and the few tools I don’t have for the next valve service. Tired of this garbage. I’m taking it to a shop I’ve used before to have them diagnose the issue. After calling the shop that did the work, they offered “to check the sensors”. Dude, you had it for three weeks. Should have checked them then. 

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Intake pressure sensor 1 is the sensor that measures manifold pressure and is connected to the three vacuum hoses by tee pieces. It should be connected to a plug with the Blue, Pink, and Black/Blue wires. The only difference being the pink which is pink/white on the atmospheric pressure sensor. Easy mistake to make. I always mark them though. Easy check too, tank and air box off. You do not need to take throttle bodies off to do the valves but I would check them out for cleanliness and tight clamps etc.

Edited by Buggy Nate
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I'm looking at the valve sheet going huh? and could we get more oil on the paperwork?

I've been doing ALL my own work on cars and bikes since the late 80s.

I dont think I could afford to ride at those prices.

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11 minutes ago, peteinpa said:

I'm looking at the valve sheet going huh? and could we get more oil on the paperwork?

I've been doing ALL my own work on cars and bikes since the late 80s.

I dont think I could afford to ride at those prices.

I wasn’t particularly soothed by the scratched out numbers. I only ever did valves on my Honda CB500X. That little twin was easy enough to figure out, but after the time and cash drain this last month has been, I think I’ll learn the triple. 

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Your tech mis-spoke.  Rest assured that your exhaust valves were TIGHT. The scratched out numbers are the shims that WERE installed, Un-scratched number is the shim size he installed to bring them into spec (in theory?).  The numbers marked are missing a decimal point, but are 0.15mm, 0.20mm, 0.28mm ETC. both EX and IN factory spec is noted, just missing the decimal point. 
 

#1 cyl LH exhaust valve number concerns me though... jumping from a 150 to a 145 shim isn’t enough to bring that tight of a lash into spec (.15mm measured is probably only jumping to 0.20mm with that small amt of a shim change - maybe that’s one he adjusted twice and he only recorded the second and third shim choices?

my other issue is that there are no AFTER measurements - how do we know the shim size selected was correct? Did he verify the lash afterword?

I’m 95% positive that your running issues are caused by a vacuum leak or the exhaust cam timing being off 1 tooth.  Pull the valve cover and check the cam timing.  

there are 2 identical Intake Air Pressure sensors on these bikes and you can check them quickly in your garage.  check operation on DIAG channel d03 and d04, the numbers on the display should fluctuate while cranking the engine (it doesn’t matter what they are exactly, they just need to change). Being that your battery is weak however, you may have trouble testing this in DIAG mode without a charger connected (the system “kicks” you out of DIAG mode if the battery voltage drops below a certain threshold). 

hate to say it, but someones gonna have to pull the valve cover and check the cam timing.

Keep us posted and good luck.

-skip

 


 

Edited by skipperT
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Thank you @skipperT! I’ll see if I can run the diag tomorrow. If I can’t, I’ll have the other shop do it. I noticed today my fairings weren’t even reinstalled correctly. Amazing.  I wish I had more time to dig into this, but I am moving this weekend. Bought a house last month and have been doing some remodeling, hence the hiring of “professionals” to do the bike service 🤦‍♂️

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  • 1 month later...

An update, over a month later. 
 

I did drop it off at a shop I have used before and trust. But it’s smaller, and between being small, holidays, and COVID, they didn’t get to look at it until this past weekend. 
 

He did a compression test, and got about 100psi on every cylinder. The bike does have 50k miles on it, but he was surprised it was that low, and as it wasn’t having problems before the last shop serviced it, he’s checking their work on the valves today. If I’m really lucky, I might have it back this week!

 

In other news, I’m looking at a 2018 Zero S because this type of headache isn’t worth it on a what is now just a commuter bike. If I was still canyon carving or cross country touring, I’d put up with it. Nothing against Yamaha; it’s been a great bike until I let someone else touch it. 

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Glad you got some more data. Don’t sweat the compression number, being a YCC-T engine, you’d have to MANUALLY prop open the throttle butterflies to get air in for good numbers AND connect a jumper battery.  I’m assuming he didn’t do that, because you should be pushing 175 or so in my mind. Though I should check mine for actual data....
Leakdown test and valve timing inspection will tell all. Fuel pressure check is a good idea too. 
Good luck. 
-Skip

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2 hours ago, skipperT said:

Glad you got some more data. Don’t sweat the compression number, being a YCC-T engine, you’d have to MANUALLY prop open the throttle butterflies to get air in for good numbers AND connect a jumper battery.  I’m assuming he didn’t do that, because you should be pushing 175 or so in my mind. Though I should check mine for actual data....
Leakdown test and valve timing inspection will tell all. Fuel pressure check is a good idea too. 
Good luck. 
-Skip

I will readily admit to being of no mechanical mind, so I have no idea how he did it 😂

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