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Author Topic: 2019 Bolt Idle and Koso Meter Questions  (Read 723 times)

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Offline dcdshadow1

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2019 Bolt Idle and Koso Meter Questions
« on: May 24, 2020, 09:52:07 pm »
Hey guys, new member here.

So I just purchased a 2019 Yamaha Bolt R-Spec off the showroom floor (great deal) and Iíve already started modding it to my liking. Handlebars, saddlemen seat, V&H Comp Series Slip on Exhaust, Koso Meter, and more on the way. However Iím wondering from what Iíve seen if the 2019 Bolt differs from previous years.

First off, I had no issues when the bolt was stock, felt good, rode good, but I couldnít hear the exhaust for the life of me. I added the V&H exhaust which most people say is no problem on a stock Bolt, no idle issues, no lean issues, etc., I noticed some pops on decel but performance seems good. That doesnít bother me. The thing that Iím worried about is my idle ďbouncesĒ or ďsearchesĒ from 1000rpm to 900rpm and back every few seconds, from my understanding this is because the exhaust changed some things and added less restriction in the system. My only concern is that Iím running too lean or something, however I can definitely smell my fuel in the exhaust in the garage or when the bike is sitting and Iím behind it.

Havenít synced the carbs yet as the hoses were very hard to get off and I didnít want to rip them. Not sure if thatís something to try first. But others have said to get Ivanís flash and thatíll take care of everything. Just wanna see if anyone else has had this problem and what could be the cause, if itís the exhaust or not.

Lastly, my koso meter is awesome I love it, but since I installed it when I turn the key to the ďoffĒ position, a loud mechanical noise comes from the air box/cylinder area almost like the fuel pump. This never happened before. What does this mean?

Thanks you guys hope to hear from everyone!

- Dave



Offline srinath

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Re: 2019 Bolt Idle and Koso Meter Questions
« Reply #1 on: May 24, 2020, 10:27:49 pm »
That hunting for idle would be a sign that its lean. However the V&H still uses the stock O2 sensor ? If not, that may be your issue in your case. I dunno a fuel controller or a flash would fix that ? no idea.

Cool.
Srinath.

Offline dcdshadow1

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Re: 2019 Bolt Idle and Koso Meter Questions
« Reply #2 on: May 24, 2020, 11:48:01 pm »
So it IS a sign of lean. Could this damage my engine at all? Really donít want to risk that as I just got it brand new. Still not sure on a solution myself. Thinking of calling Ivan from Ivanís performance and see what he has to say. The exhaust does use the stock O2 sensor.

- Dave

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Offline srinath

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Re: 2019 Bolt Idle and Koso Meter Questions
« Reply #3 on: May 25, 2020, 12:17:18 am »
Well its really not likely to be lean if the o2 sensor and all other sensors are on.
Maybe your gauge is too sensitive.
So to put it in more carbureted bike terms - this is what it would do if you mod the intake or exhaust without rejetting it.
If you set the idle when cold, and you set it to say 1200. If the bike is lean, once it gets hot, it would idle at 1500 to 2000 and hunt for idle there - like it would rev up and drop down a bit on its own. If you're just having it fluctuate between 1000 and 900 hot or cold, I'll guess your gauge is just a bit fluttery.
You may just be fine, I don't know what my idle rpm is, but I can guess its not off more than a 100 or so between hot and cold and not more than a 100 of flutter - except I got no tach, stock gauge, so I am blissfully unaware.
Cool.
Srinath.

Offline dcdshadow1

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Re: 2019 Bolt Idle and Koso Meter Questions
« Reply #4 on: May 25, 2020, 12:39:20 am »
It hunted for the idle before the gauge was installed, I thought about it a lot but wasnít sure, the gauge just solidified my suspicion. Itís audible to hear it hunt in that small range. So itís not just the gauge reading off. Still think this is a problem? That makes sense for carbureted terms. What are you running as far as intake exhaust? It was pretty obvious for me to hear the change. As long as my engine isnít being damaged from being too lean I donít mind it, even though I like a smooth idle to know things are running well. Just wanna make sure Iím not hurting the cylinders etc.

- Dave

Offline lunkhead

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Re: 2019 Bolt Idle and Koso Meter Questions
« Reply #5 on: May 25, 2020, 01:10:23 am »
You need to sync the idle circuit. Could be way off as some have reported. Mine was good enough when checked with a cheap guage. Being out of sync is the most common reason for an unsteady idle. Ivan's flash bypasses the O2 sensor which will eliminate that as a problem.
C-SPƎC

Offline dcdshadow1

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Re: 2019 Bolt Idle and Koso Meter Questions
« Reply #6 on: May 25, 2020, 01:18:18 am »
Lunkhead, are you referring to the vacuum ports in the intake? If so then I will probably do that ASAP and report back on if it fixed anything. I heard Ivanís bypasses, I didnít know the synch worked in conjunction with the idle speed.

- Dave

Offline bedheadjulian

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Re: 2019 Bolt Idle and Koso Meter Questions
« Reply #7 on: May 25, 2020, 01:43:59 am »
Anyone who modifies their intake/exhaust should know how Yamaha has designed their ECU's to run in  order to make an informed decision. This has been a hotly debated topic but no one has discussed when and how the ECU checks fuel/air rations. The key factor is when the system runs in "open loop" and when it runs in "closed loop". When it runs in open loop it does not check the ratio, it just runs on the maps based mostly on throttle plate position. This video explains it clearly. Here's a link:

https://www.youtube.com/watch?v=fujeAFAjb4A


Offline lunkhead

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Re: 2019 Bolt Idle and Koso Meter Questions
« Reply #8 on: May 25, 2020, 03:28:08 am »
Quote from: dcdshadow1
I didnít know the synch worked in conjunction with the idle speed.

Anything out of sync between cylinders will affect steady idle speed. That's why it's important to check valve lash before syncing.
C-SPƎC

Offline srinath

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Re: 2019 Bolt Idle and Koso Meter Questions
« Reply #9 on: May 25, 2020, 09:47:09 am »
I got a cheapo ebay Chinese slip on. O2 sensor is intact as are all other sensors and stock air filter which has been blown clean a few times and never even got dirty.
Cool.
Srinath.

Offline dcdshadow1

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Re: 2019 Bolt Idle and Koso Meter Questions
« Reply #10 on: May 25, 2020, 11:14:00 am »
So Julian, I watched this video and it was very informative. But now understanding this is happening at open loop, would that mean syncing my cylinders, etc. will do nothing? It seems to me the only way to fix this is either a tune, fuel controller, or go back to stock exhaust. Which sucks because I paid good money for a nice pipe. What is the solution to this?

Lunk, this goes under the same thing. I am curious to synchronize the cylinders and all that, wouldnít be hard for me. Iím just wondering if that will fix the idle issue or not.

Srinath, you donít hear any idle difference on your bike at all? What year is it? I heard that they couldíve changed the ECU to latest models which makes it like aftermarket less.

- Dave

Offline lunkhead

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Re: 2019 Bolt Idle and Koso Meter Questions
« Reply #11 on: May 25, 2020, 12:28:00 pm »
The Bolt's intake timing is relatively early which is conducive to smooth idle regardless of exhaust (within a reasonable size, of course). If timing was designed late as with a hot cam, idle speed would be rougher and an exhaust change could influence it negatively by promoting reversion. If you don't sync everything, one cylinder will try to idle higher or lower than the other. If you change cam timing or have the wrong exhaust dimensions, it would just be rougher all around. Syncing is the ONLY maintenance item done specifically for good idle and it includes checking anything (valve lash, intake leaks, etc) that could make things uneven prior to a final TB sync. NO EXHAUST, INTAKE, FLASH, ETC CAN STABILIZE THE IDLE SPEED IF THE CYLINDERS AREN'T SYNCED.
C-SPƎC

Offline dcdshadow1

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Re: 2019 Bolt Idle and Koso Meter Questions
« Reply #12 on: May 25, 2020, 08:00:18 pm »
To Lunk and all else. I just used the ďcheap carb synch toolĒ and synched my cylinders. I will say this was WAY off when I checked it and it did smooth out the engine. However, the idle issue seems to remain, maybe a little less but it is still there. Possibly my gauge is very sensitive but if you listen closely you can hear the pitch change. From 1000 to 900 not so much, but at one point it dips below 900 and shoots up to 1000 to counter for it. Any thoughts? Am I just being OCD about my air cooled V-Twin? Here is an accompanied video.

(Ignore my fuel light coming on.)

https://youtu.be/s4aXahgqJVg

- Dave

Offline DrM

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Re: 2019 Bolt Idle and Koso Meter Questions
« Reply #13 on: May 25, 2020, 08:55:03 pm »
@ dcdshadow1 -- just my opinion, but I think you might be imagining a pitch change just because you're watching the KOSO tach needle move, which may have its own built-in errors.

Offline srinath

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Re: 2019 Bolt Idle and Koso Meter Questions
« Reply #14 on: May 25, 2020, 11:32:03 pm »
I have not synched or done valves or anything else on my bike in the 18 months I have owned it. Essentially mods - yes the relevant one has been the slip on from ebay, maintenance has been oil filter and oil and blowing air filter clean 3X in 8900 miles. It seems to have a steady idle, but I don't know if its fluttering the 100 rpm or not - other than seeing it on the tach do you hear it ? Cos I am sensitive to the way it would sound and feel, but I got no tach. To me it sounds and feels smooth.

Cool.
Srinath.