• Ciao Guest - You’ve landed at the ultimate Guzzi site. NEW FORUM REGISTRATIONS REQUIRE EMAIL ACTIVATION - CHECK YOUR SPAM FOLDER - Use the CONTACT above if you need help. New to the forum? For all new members, we require ONE post in the Introductions section at the bottom, in order to post in most of the other sections. ALWAYS TRY A SEARCH BEFORE STARTING A NEW TOPIC - Most questions you may have, have likely been already answered. DON'T BE A DRIVE-BY POSTER: As a common courtesy, check back in and reply within 24 hours, or your post will be deleted. Note there's decades of heavily experienced Guzzi professionals on this site, all whom happily give endless amounts of their VALUABLE time for free; BE COURTEOUS AND RESPECTFUL!
  • There is ZERO tolerance on personal attacks and ANY HYPERLINKS to PRODUCT(S) or other competing website(s), including personal pages, social media or other Forums. This ALSO INCLUDES ECU DIAGnostic software, questions and mapping. We work very hard to offer commercially supported products and to keep info relevant here. First offense is a note, second is a warning, third time will get you banned from the site. We don't have the time to chase repeat (and ignorant) offenders. This is NOT a social media platform; It's an ad-free, privately funded website, in small help with user donations. Be sure to see the GTM STORE link above; ALL product purchases help support the site, or you can upgrade your Forum profile or DONATE via the link above.
  • Be sure to see the GTM STORE link also above for our 700+ product inventory, including OEM parts and many of our 100% Made-in-SoCal-USA GTM products and engine kits. In SoCal? Click the SERVICE tab above for the best in service, tires, tuning and installation of our products or custom work, and don't miss our GT MotoCycles® (not) art on the BUILDS tab above. WE'RE HERE ONLINE ONLY - NO PHONE CALLS MADE OR RECEIVED - DO NOT EMAIL AND ASK QUESTIONS OR ASK TO CALL YOU.
  • Like the new V100, GuzziTech is full throttle into the future! We're now running on an all-new server and we've updated our Forum software. The visual differences are obvious, but hopefully you'll notice the super-fast speed. If you notice any glitches or have any issues, please post on the Site Support section at the bottom. If you haven't yet, please upgrade your account which is covered in the Site Support section or via the DONATE tab above, which gives you full site access including the DOWNLOADS section. We really appreciate every $ and your support to keep this site ad-free. Create an account, sign in, upgrade your account, and enjoy. See you on the road in 2024.

V7 Classic running rich on one cylinder, stalling

C

ChrisH

Just got it firing!
Joined
Jun 15, 2010
Messages
9
Hi all,

My V7 Classic now has 7,500km on the clock and has developed a hot idle problem.

Starting and general running are fine and the engine idles at the correct 1100rpm when just warmed up. But after half an hour or more of riding, when the engine's up to proper working temperature, the idle becomes lumpy and the engine will eventually stall. As you can imagine, this is not good in city traffic ...

The problem seems to be the right cylinder—the plug is blacked up whereas the left cylinder is clean. There's also a smell of raw gas, so it's not getting burnt off properly in the right cylinder.

Swapping the plugs didn't solve the problem so it's not them. (Again, the righthand plug got fouled.) The valve clearances and the compression are checked and both fine. There are no fault codes on the Axone diagnostics. The bike runs just fine on the highway.

Has anyone here had a similar experience? Any ideas as to what it might be?

Thanks,

Chris
 
Thanks for the suggestions, Pete — I'll investigate. Not sure what you mean by 'Pack ETS' though?

Cheers,

Chris
 
Chris, checking the throttle body balance is a good idea. I'm surprised that one cylinder is running that rich and no problems are shown in Axone. Perhaps using the Axone to test/check each component?

Regardless, adjusting throttle body balance is something you can do yourself and may provide the solution without going back to the dealer. Here's a link to making your own manometer; http://www.obairlann.net/reaper/motorcycle/manometer.html

Let us know how it works out,
Joe
 
ChrisH said:
Thanks for the suggestions, Pete — I'll investigate. Not sure what you mean by 'Pack ETS' though?

Cheers,

Chris
Click to expand...

Pack ETS means to put a heat conductive paste on the engine temperature sensor. This is in many of the tuning topics for both small and big block bikes.
 
Thanks for clearing that up John — had me puzzled for a while there!

Chris
 
The right cylinder has the fuel enrichment/choke cable, see if it stuck in the on position at the throttle body
 
That's a good point—the 'choke' lever on the bike has never managed to stay fully on. I can pull it all the way to the end of its travel before feeling resistance in the last 5mm or so, when the revs will rise for about 10 seconds. And then you have to pull it again to keep the revs high. Something not right there.
 
sign216 said:
Chris, checking the throttle body balance is a good idea. I'm surprised that one cylinder is running that rich and no problems are shown in Axone. Perhaps using the Axone to test/check each component?

Regardless, adjusting throttle body balance is something you can do yourself and may provide the solution without going back to the dealer. Here's a link to making your own manometer; http://www.obairlann.net/reaper/motorcycle/manometer.html

Let us know how it works out,
Joe
Click to expand...

Yes you can balance yourself, but you must have VDSTS or the Guzzi software to reset the TPS. Balancing without resetting the TPS can make matters worse.
 
ChrisH said:
That's a good point—the 'choke' lever on the bike has never managed to stay fully on. I can pull it all the way to the end of its travel before feeling resistance in the last 5mm or so, when the revs will rise for about 10 seconds. And then you have to pull it again to keep the revs high. Something not right there.
Click to expand...


My Breva was exactly the same. The "choke" is just a fast idle bodger that moves the throttle on the "carb" body via a cam and roller. The return spring at the throttle body is ridiculously strong. I swapped mine for a lighter spring, and at least it stays on now. It also doesn't move very far, so you have to make sure the cable isn't adjusted too slack.
 
Check the resistance of the plug caps!! The "choke/enrichner" does neither. That control only controls idle speed, advancing it when cold allows the engine to keep running. I would be looking at things that the Axone can't see, plug caps, plug wires, ( chafed or shorted ) air flow restriction ( delamination of intake tube?? ) for starters. The plug cap thing is a constant problem on late model big block Guzzis, every time someone tells me that their bike won't idle when warm but runs ok when at higher RPMs I check plug caps. An open circuit cap sometimes allows spark at higher RPMs and none at idle speed.

Brian
 
I'll check that too, thanks.

The throttle sensor and the engine temp sensor both checked out okay, so the bike is going back to the workshop on Monday for more investigation, including the rhd fuel injector and the fuel pump.

Will let you know how it goes!

Thanks for all your suggestions,

Chris
 
Did you ever sort this?

My 750 Breva is doing the exact same thing now....
 
In the end, the workshop fitted a new throttle sensor, rebalanced the throttle bodies, took out the engine temp sensor and refitted it with a heat conductive paste, and raised the idle point a fraction. Then the bike went onto the dyno for a check.

It seems to have fixed 75% of the problem. On open road running the bike is fantastic, with really sharp throttle response. When it gets very hot after a long (hour or more) run, the idle isn't creamily smooth, and it occasionally stumbles. But it's nowhere near as bad as it was.

Hope this helps,

Chris
 
Thanks.

Following threads on here I have

Checked the cylinder balance: perfect @3000rpm, needed no adjustment.
Removed the engine temp sensor and packed with arctic silver heat conductive paste.
Checked the tappet clearances.
Changed the plug caps.
Changed the plugs.

Feels like a low tension circuit to me, the position/rpm sensor does the spark: maybe there is something wrong with it, or a corroded connection. It appears to be the right cylinder that misses, the vacuum gauge on that cylinder jumps like crazy on a stumble, the right doesn't. (Maybe it is valves?) Certainly the right plug is getting sooty.

If I can't fix it, it can go to the back of the shed and I'll trade it in next year on a new 'bike.
 
Facade said:
Thanks.

Following threads on here I have

Checked the cylinder balance: perfect @3000rpm, needed no adjustment.
Removed the engine temp sensor and packed with arctic silver heat conductive paste.
Checked the tappet clearances.
Changed the plug caps.
Changed the plugs.

Feels like a low tension circuit to me, the position/rpm sensor does the spark: maybe there is something wrong with it, or a corroded connection. It appears to be the right cylinder that misses, the vacuum gauge on that cylinder jumps like crazy on a stumble, the right doesn't. (Maybe it is valves?) Certainly the right plug is getting sooty.

If I can't fix it, it can go to the back of the shed and I'll trade it in next year on a new 'bike.
Click to expand...

Swap the coils. See if the miss goes to the other side. Has the TPS been reset? Alfalin_0 (with VDSTS) should be 3.1 degrees.
 
I can't reset the tps, but I haven't touched any base settings. If it needs doing that often (2 1/2 yrs old now 4500 miles) I really don't need the hassle. It should be set once then forget forever.

The nearest dealer is a good hour away, and only open when I'm at work, and I suspect 30 seconds with axione is not cheap.

Swapping the coils is a good idea, if there is only one pickup I would have expected both cylinders to missfire, bet the tank has to come off though.
 
Had the same problem with my Breva and found a leaking injector. You can swap the injectors and see if the problem follows.good luck
 
Facade said:
I can't reset the tps, but I haven't touched any base settings. If it needs doing that often (2 1/2 yrs old now 4500 miles) I really don't need the hassle. It should be set once then forget forever.

The nearest dealer is a good hour away, and only open when I'm at work, and I suspect 30 seconds with axione is not cheap.

Swapping the coils is a good idea, if there is only one pickup I would have expected both cylinders to missfire, bet the tank has to come off though.
Click to expand...

The TPS is a variable resistor. Over time and usage the values will drift. Doing a reset once a year or so is a good thing. Also when you do a throttle body balance, you need to reset the TPS. You can do the TPS reset yourself with VDSTS. Also run diagnostics on components to include coils, injectors furl pump....
 
Guess what,

today it ran as sweet as a nut, nary a stumble

Monday: fine.
Tuesday : bag of nails, stumbling & cutting out during gearchanges.
Wednesday: bag of mails, ditto.
Thursday, pretty much unrideable, worst its ever been.
Friday, purrs like a kitten.

It must be a connection somewhere.

It has done this since I've had it, fine for months, then terrible for a couple of days, then fine again.
 
You must log in or register to reply here.
Back
Top