• 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.

2016 V7II - Surging after fuel filter change - found issue

hatchb4ck

Tuned and Synch'ed
Joined
Aug 25, 2017
Messages
34
Location
Overland Park, KS
I'm trying to keep my head up with regards to my 2016 V7II Stornello, but I'm struggling with it. Aside from the rough running and stalling when it rains, I have now introduced a new issue with my fuel filter change. I really wanted to order one from GT, but since I didn't have anything else to order, the shipping was about half the cost (no criticism here...just an deciding factor. I dig what GT offers us Guzzi owners) ...so using the parts cross reference, I picked up a Napa 3032 filter and some 11.3 Oetiker clamps.

Pulled the pump, uninstalled the stock filter, installed the new filter double and triple checking the flow direction, clamped it and reinstalled. Fired up the bike and it idles, rolled the throttle on and it revs for a second or two then the rpms decrease and it backfires. If I hold the throttle steady, it will rev up and down in a regular timing pattern.

I pulled the tank back off, pulled the new filter, reset the hoses, installed new clamps, pump back in the tank, and back on the bike... Naively hoping that maybe I didn't have the clamps on correctly the first time. Nope, still having the issue.

The behavior, to me, is a fuel pressure/volume issue. Thoughts?
 
Found the issue....the tank wasn't venting properly. I discovered it while leaning over the tank while lifting it from the rear. I heard an audible "venting" sound. So I popped the gas cap, checked all the vent lines and made sure everything is sorted. Started it up...no surging issue.

Hopefully this post helps remind others to check the tank vents after reinstalling the tank.
 
My $0.02: It's easy to pinch the vent hose closed when putting the tank back on. When you lifted the rear of the tank, the hose became unpniched. I suspect that many (maybe all) reports of tanks not venting properly are due to pinched vent hoses rather than anything being wrong with the venting valve.
 
What is going on with your surging? Like what does that mean?

I ask cause I"m trying to track down a demon right now and kind of just lost for words on what else I could possibly do to fix the issue. For about the last 1.5 years I've had "surging" and a gargling exhaust sound at specific times of the RPM range. I'll have a surge of power after a slight loss of power at 4500 rpm. I'll have a gargling exhaust if I come off the throttle then usually some slight back fires, then around 50% of the time, I'll have no power to take off - like can't get to 45mph unless i jump to 3rd gear and pull the throttle fairly close to wide - and then the power will be fine after that.

Replaced fuel filter, cleaned up oil in breather box, replaced spark plugs twice, replaced spark plug wire, replaced battery, replaced a head gasket thing that had created residual oil up by the spark plug.

Just kind of lost now what to do next, but wondering if I am having something similar to you. Don't hear any venting though, so maybe it's a different kind of surge?
 
What is going on with your surging? Like what does that mean?

I ask cause I"m trying to track down a demon right now and kind of just lost for words on what else I could possibly do to fix the issue. For about the last 1.5 years I've had "surging" and a gargling exhaust sound at specific times of the RPM range. I'll have a surge of power after a slight loss of power at 4500 rpm. I'll have a gargling exhaust if I come off the throttle then usually some slight back fires, then around 50% of the time, I'll have no power to take off - like can't get to 45mph unless i jump to 3rd gear and pull the throttle fairly close to wide - and then the power will be fine after that.

Replaced fuel filter, cleaned up oil in breather box, replaced spark plugs twice, replaced spark plug wire, replaced battery, replaced a head gasket thing that had created residual oil up by the spark plug.

Just kind of lost now what to do next, but wondering if I am having something similar to you. Don't hear any venting though, so maybe it's a different kind of surge?
Sounds like it’s running lean Are you still running the stock map?
 
Sounds like it’s running lean Are you still running the stock map?

I don’t think this is it, I am running a custom map built for this bike and exhaust. And it’s not consistently surging and not consistently losing power. If it randomly reseted back to the stock map would that actually be a sign, and why would it go back to normal sometimes?
 
I don’t think this is it, I am running a custom map built for this bike and exhaust. And it’s not consistently surging and not consistently losing power. If it randomly reseted back to the stock map would that actually be a sign, and why would it go back to normal sometimes?
Tyler, instead of fishing the net, just write me direct email. Too much misinformation posted... and I know your bike well outside of anything done when it’s not at my shop. ;)
The map cannot revert. Impossible.
It may be related to heat, sitting in the sun, or just traffic and riding conditions. These are air-cooled engines that can get cranky on warm weather. You may know enough to realize when this happens on other (farm) vehicles?
Your bike tested A-OK last we had it. No errors, no running issues.
 
What is going on with your surging? Like what does that mean?

I ask cause I"m trying to track down a demon right now and kind of just lost for words on what else I could possibly do to fix the issue. For about the last 1.5 years I've had "surging" and a gargling exhaust sound at specific times of the RPM range. I'll have a surge of power after a slight loss of power at 4500 rpm. I'll have a gargling exhaust if I come off the throttle then usually some slight back fires, then around 50% of the time, I'll have no power to take off - like can't get to 45mph unless i jump to 3rd gear and pull the throttle fairly close to wide - and then the power will be fine after that.

Replaced fuel filter, cleaned up oil in breather box, replaced spark plugs twice, replaced spark plug wire, replaced battery, replaced a head gasket thing that had created residual oil up by the spark plug.

Just kind of lost now what to do next, but wondering if I am having something similar to you. Don't hear any venting though, so maybe it's a different kind of surge?
I had a somewhat similar problem. Something to check: Are the connectors fully seated and clipped in properly? I had one that wasn't, and the vibration at different rpms would cause loss of power.
 
I had a somewhat similar problem. Something to check: Are the connectors fully seated and clipped in properly? I had one that wasn't, and the vibration at different rpms would cause loss of power.
I realized that I left out some detail: I was referring to the electrical connection to the fuel injector.
Dan
 
I realized that I left out some detail: I was referring to the electrical connection to the fuel injector.
Dan

Worth a check! I've been really trying to ride the bike non stop with just Chevron high end fuel too. I fear ethanol might have crystallized on the injectors from the bike sitting when I had a leak and couldn't fix at the moment. Since I started putting 70 miles on it per day that seems to really have cleared things up and made the issue very much more in frequent.
 
Back
Top