Solving the "Startus Interruptus" on my Moto Guzzi 1200 Sport
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- Опубліковано 24 сер 2024
- Thanks to my subscribers for the trouble shooting tips and Ronnie Moore for the link to Mph Cycles for the kit to fix my Moto Guzzi 1200 Breva Sport.
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The additional information you may find useful (which I also shared a long time ago on the GuzziTech forum):
I bought a Moto Guzzi Breva 1200 back in 2011. It is a 2008 model. For several years I did not experience any issues related to the starter. However, it finally popped up and started giving me grief, especially in situations where I least wanted to see it happening.
I am an engineer (electrical, software) in the automotive industry, so I decided to look into the issue after reading the extensive discussion on the subject online.
I checked the schematics and measured things, also with an oscilloscope (during crank) and got some interesting results. You see: there is no direct connection between the red start button and the starter relay. Instead, this button is wired to the ECU (or DSB, not sure now - but it isn't that important) and it is the module that recognizes the command from the rider to start the engine. However, it must check if the conditions for a safe crank are met. Specifically: the kick-stand, the neutral status, the clutch lever position and who knows what other conditions. Sure, those checks are super fast, and last only a fraction of a second to complete. Once all conditions are satisfied the controller module may activate the coil in the starter relay. In my case it did and it was clearly audible. However! The controller continues to operate and monitor the situation as it activates the crank cycle. My guess here is that it detects the voltage drop and is overly sensitive to it. So, the reaction is instant - the deactivation of the starter relay. So, the click is heard and the starter relay closes the main, high-current circuit to allow a crank, but before the crank happens it gives up and opens the circuit before the starter moves the crankshaft.
It is easy to simulate the action of the controller by touching the coil terminal which is normally wired to the module with a wire (fused, let's say) whose other end is connected to a positive terminal on the battery. It always gives a clean crank without any hesitation. BEWARE, though!! When you try that ALL THE SAFETY conditions are bypassed, so you may crank the engine whilst in gear (the computer checking everything is now your brain! Be extra careful and double check everything). Also, since it is a manual crank you must open the starter circuit as soon as the engine is started or the starter may be damaged. Normally it is the controller module that does it automatically based on the crankshaft's RPM sensor.
Now, this all means that it's not necessarily the bad contacts or faulty relay (yeah, those can happen, but if there is absolutely nothing wrong there, then.... see above) but rather the unfortunate system design:
when one looks at the schematics one can see the line from the battery that is monitored by the controller module branches off to all different parts here and there. In the physical world, it means that the distance from the battery terminal (just under the saddle) to the location of the electronic modules is quite long. My friend who designs electrical harnesses for vehicles said it is quite common to splice wiring inside the harness. I am sure the Guzzi harness has multiple splices on this particular line which may contribute to the problem (i.e. the central module sensing something it doesn't like during crank and aborting it). I wonder if routing a dedicated wire from the relay's coil all the way to the sensing pin on the controller module would also fix the starter issues for good. Who knows...
So, yet another perspective on this *Startus Interruptus* phenomenon.
I'll pin this. Many thanks.
@@flatcapcaferacer Sure, glad you find it useful.
Probably the best explanation I have received!
@@flatcapcaferacer Hah! I just found something that is a better one (and confirms my hypothesis):
ua-cam.com/video/dOIo3XpaOds/v-deo.html&lc=UgyIVks8ts8vf2fNG-54AaABAg
it seems the link does not point to the comment directly, so look for:
_There was an article in the Moto Guzzi magazine (Gambalunga) Dec 2023, regarding the "click no start" issue for CARC bikes. It seems that in the original wiring diagram by Moto Guzzi it shows a diode and capacitor which are there to provide a hold current to the ECU whilst pressing the starter button. Unfortunately for some reason Moto Guzzi decided to save a few pennies and not bother fitting them and instead just bypassing the places where the components should of been fitted with a simple jumper wire._
Glad you found a Cheapus Fixus for it!!
😅😅 My subscribers are the best Roger. I sure don't know everything and probably less every year so it is good to get some help.
This is a true Moto Guzzi owner type comment. The Moto Guzzi faithful are a pretty cheap bunch.
@@ronmoore1 😄😄
Please do NOT quit videoing!
Sorry but I started the count down already. I need Roy's help on two or three I left to do, and you and Rob to do the finale.
I'll keep doing regular videos when the inspiration comes up but I'm using the four videos I want to do as the measuring stick to wrap it up.
Looks like a simple job and a straight forward part. I like that kind of ingenuity.
Heck old buddy it takes two us to put on a Tiger Seat so the bar isn't set that high.🤣
Like the detective work finding the problem. Great solution 👌
Good thing some of my viewers are there to help me out.
Glad you found a way from Startus Interruptus to Startus Perfectus 👍😀
Me too Michael, I feel much better now.
Glad it solved your issue, if you want some clarifications on any points of this or any other Guzzi question I am easy to reach. Mike Haven, MPH Cycles. I developed the kit.
Thanks Mike for coming through so quickly with a resolution for my problem.
Great job. No more "ridus interuptus".
Credit goes to Ronnie Moore for getting me on the right track, Ken on Wild Guzzi and Mike and Kim for the part.
Jerry
When I saw startus interruptus, I was hoping the fix was not Viagra.
😆😆😆 me too.
Cialis works better for "that" kind of stuff. Don't ask me how I know.
After install, it sounded to me like the starter spun stronger.
I know on my Roadsters, increasing battery wires to #4 from OEM #8 made a huge improvement.
I thought it did too Steve but I thought it might have been my imagination.
I you and Rob are ready for Bonneville, only five or so weeks.
So, the bike did start without the fix and it also started with the "fix". But based on that one cannot tell for sure if the original issue is solved. This video is now 9 months old, so would you please share the status? Has the interruptus been gone since the installation of the additional circuitry?
Never came back again 👍
@@flatcapcaferacer Great result!
I hope that fixes your problem. Given the bike didn’t already have the fix makes me think your problem is likely solved. When someone says they have a well sorted Moto Guzzi these items are what they mean. Not major failures just annoyances.
I really appreciate your tip Ron👍👍
@@flatcapcaferacer Just to keep you in the loop, I traded the Moto Guzzi V85TT for a Yamaha Super Tenere. I always felt I was abusing the V85TT when crossing the country. I still have the MG V7III. I almost bought a Triumph Tiger 1200 Explorer GT but the dealer was just not very responsive.
There are a lot of dealers across all brands like that unfortunately. Congrats on the Super Tenere and sorry about losing the Guzzi but you do cover a lot of miles so that is understandable.
I hope you still drop in here occasionally, your advice and insights are always welcome.