Calvin Mileage Dropoff and Fuel Light Problem (New Questions)

[JC85]

So the mileage on my 2007 Calvin has recently taken a dump. Over the last few weeks, it's gone from 40+mpg to 35mpg. It happened suddenly on a weekend trip up to Lawrence to see some friends. I got about 40 on the way there, then got 35 on the way back. At first I thought maybe some crappy gas. But after filling up here at home, it's still at around 35.

The second issue is that the low fuel warning light is coming on at about 100-110 miles. Now, I've been told and am aware that the low fuel light on a Calvin comes on when the tank still has1.5 gallons of fuel in it. Still, even with the bad mileage I'm getting, it came on when I'd only used 3.112 gallons, today.  So if it is coming on with 1.5 left, then that's only about 4.4 gallons, total, which is nearly a full gallon less than Guzzi's stated 5.5 gallon capacity. Anyone else had these issues or have any tips?

P.S. I run nothing but premium, and nothing about my riding habits or the amount of highway vs in town miles has changed, recently.

Thanks in advance.

[guzzisteve]

Just so you know WE didn't make the thing. Maybe call the 800# and tell the mfg. but look at what you haven't looked at yet. Have you actually cleaned the TB's and removed the air bleed screw and cleaned them? I do mine every 10K mi. How about setting the TPS? How about the air filter or fuel filter? When was the last time anything got attention? I know how all the cheap suspender snappers are, do nothing and expect things to run forever.

The CalVin should be getting 50 mpg or it's not tuned correctly. AND I'm not trying to give you any grief about it. It's your bike.

[JC85]

Just so you know WE didn't make the thing. Maybe call the 800# and tell the mfg. but look at what you haven't looked at yet. Have you actually cleaned the TB's and removed the air bleed screw and cleaned them? I do mine every 10K mi. How about setting the TPS? How about the air filter or fuel filter? When was the last time anything got attention? I know how all the cheap suspender snappers are, do nothing and expect things to run forever.

The CalVin should be getting 50 mpg or it's not tuned correctly. AND I'm not trying to give you any grief about it. It's your bike.

It never ceases to amaze me how some people on this board get nasty when someone asks for advice and input. As if that wasn't one of the purposes of the board, in the first place. I'm already planning on checking a few things. But I have limited mechanical knowledge, especially with modern bikes that have fuel injection and computers, so I was simply wondering if anyone had any specific experience with these issues and might have some suggestions.

Next!

[Guzzidad]

   I don't think Steve was getting snarky at all. He gave you some very good tips to address your issue, free. These are all things even someone with limited mechanical ability can accomplish.

[lazlokovacs]

The CalVin is dual plugged.

It could be that one or more of your plugs isn't firing. The bike wouldn't run much differently, but the burn could be much less efficient if say one cylinder is only firing one plug.

Do you have Guzzidaig?

I would connect it and try the spark plug firing test and make sure you're getting a fat spark at all 4 plugs.

Are there any other symptoms? Any oil leaks? Even slight ones?

Please keep me updated, I've got over 100,000 miles on Calvins and had them apart and back together many times. We'll get you sorted.

[lazlokovacs]

Have you actually cleaned the TB's and removed the air bleed screw and cleaned them? I do mine every 10K mi. How about setting the TPS? How about the air filter or fuel filter?

I have a lot of respect for GuzziSteve, but I don't feel confident that any of these factors would lead to a sudden drop in mileage as described.

I could be wrong but...

[JC85]

Ok. Steve, I do apologize for getting a bit testy. The tone of your message struck me the wrong way. That being said, thank you for your suggestions. Now, I'd like you to know a few things about me. I'm a relatively younger guy who, though I grew up with them, has only been riding and working on Guzzis for a few years, now. I genuinely enjoy working on and maintaining my own bikes, and am happy to do so, but as I said, I have limited knowledge, so I'm learning as I go. I'm not at all someone who just let's things go and gets upset, when they don't run right. It took me several years of hard work and research to get my dad's old Eldo sorted and gain the knowledge to do so, and this Calvin (which I just bought in October of last year) is my first modern bike. So now I'm sort of back to being lost, when it comes to issues and fixes. That's why this board and the collective knowledge of the people on it are such an invaluable resource for me, and why I come here for advice.

Anyways, no hard feelings on my end, and I hope there aren't any on yours.

[JC85]

The CalVin is dual plugged.

It could be that one or more of your plugs isn't firing. The bike wouldn't run much differently, but the burn could be much less efficient if say one cylinder is only firing one plug.

Do you have Guzzidaig?

I would connect it and try the spark plug firing test and make sure you're getting a fat spark at all 4 plugs.

Are there any other symptoms? Any oil leaks? Even slight ones?

Please keep me updated, I've got over 100,000 miles on Calvins and had them apart and back together many times. We'll get you sorted.

Thanks for the tip. My first thought was to check plugs and air filter. I'm going to pull and test the plugs, this weekend, and check the air filter, while I'm at it. No other symptoms that I can tell. Not a drop of oil on my shop floor, where I park it, power and torque seem to be as good as ever, no added engine vibration, etc.

I don't have Guzzidiag. Anything that can be wrenched on, I can handle, as long as I know or can find out how to do it. Vehicle computer issues are totally foreign to me.

[Kiwi_Roy]

The low fuel light is probably a thermistor or perhaps a float switch, Neither of these will suddenly move and operate at a different level.
Is the fuel pump making more racket all of a sudden, that could be a blocked fuel filter which would result in a higher consumption as the fuel pressure goes higher than normal.
It's normally about 40 psi but can go to 70 with a filter blocked.
If you remove the filter and pour some fuel into the outlet most of what's plugging it will run out the inlet port.

[guzzisteve]

There is an ultimate reason I did it that way, believe it or not.   It was not to be a personal attack, just to spice it up. BUT to get attention to all the questions. It was to draw attention to the thread, otherwise just will get mulled over.
If I'm a Richard then more riders will help you out.

[Chet Rugg]

JC was this after adding the top case? Seems like everytime I added something to rusty ( my 99 bassa)  it got less gas milage. Something to do with more wind drag. bags crash bars windshields . could have been more miles racking up as I was building and needed tuned too I dont know. Oh I also hooked a trailer behind it and that really changed things. Calvin is different than bassa open loop fuel injection a bit different than closed loop. You have 02 sensors I dont so guzzidag or what ever its called may be needed on yours for tweeking it on fuel milage.
Chet

[JC85]

There is an ultimate reason I did it that way, believe it or not.   It was not to be a personal attack, just to spice it up. BUT to get attention to all the questions. It was to draw attention to the thread, otherwise just will get mulled over.
If I'm a Richard then more riders will help you out.

Ok, I can appreciate that. And now that I have a feel for how you operate, I know not to take it personally, in the future. Again, no hard feelings on my end, and I hope there aren't any on yours.

[JC85]

The low fuel light is probably a thermistor or perhaps a float switch, either of these will suddenly move and operate at a different level.
Is the fuel pump making more racket all of a sudden, that could be a blocked fuel filter which would result in a higher consumption as the fuel pressure goes higher than normal.
It's normally about 40 psi but can go to 70 with a filter blocked.
If you remove the filter and pour some fuel into the outlet most of what's plugging it will run out the inlet port.

Thanks. I'll make a note of both of those.

[JC85]

JC was this after adding the top case? Seems like everytime I added something to rusty ( my 99 bassa)  it got less gas milage. Something to do with more wind drag. bags crash bars windshields . could have been more miles racking up as I was building and needed tuned too I dont know. Oh I also hooked a trailer behind it and that really changed things. Calvin is different than bassa open loop fuel injection a bit different than closed loop. You have 02 sensors I dont so guzzidag or what ever its called may be needed on yours for tweeking it on fuel milage.
Chet

Thanks for the info, Chet. It actually started, just before I added the top case.

[JC85]

Ok, guys. After reading and listening to everyone's advice, here are all of the things that I plan to check and replace, if necessary, in order:

Air filter
Plugs
Throttle bodies
TPS
Valve lash
Fuel filter

I'm also considering getting Guzzidiag and purchasing a Beetle map. Terry, the previous owner, wrote his own map for it, and I've just left it alone, as I have zero knowledge of these things. Now, a few questions:

First, can anyone tell me what fuel filter to purchase? I've looked on Mgcycle, and they're sold out of the metal ones, and I can't find the brand that they carry anywhere else. I've also read through several threads about the plastic filter issue, but haven't seen anyone mention a specific part number, brand, etc.

Next, Terry also swapped the original pipes for a set of Harley pipes to eliminate the cats, in order to make it run cooler, and he removed the o2 sensor. If I do swap to a Beetle map, will I need to swap all of that back to original? I have all of those original parts, so it's within my means. I'm just wondering if it will be necessary. I do like the sound of the pipes that are on it and the idea of the engine running cooler, but don't want to change one thing without changing the rest, if it's going to create more problems. Again, thanks to everyone for their input.

[PJPR01]

Did you check tire pressures JC? 

Brakes?  Is one of the wheels dragging?  Maybe try spinning them and check for excessive rolling resistance?

Does the throttle response feel the same or “heavier”?

[JC85]

Did you check tire pressures JC? 

Brakes?  Is one of the wheels dragging?  Maybe try spinning them and check for excessive rolling resistance?

Does the throttle response feel the same or “heavier”?

I just had new tires put on it (after this issue started; no change,) and have been regularly checking pressure, since. I pulled and resintalled the wheels, myself, when I had the tires put on, so I can confirm that they spin freely with no drag. The throttle feels as responsive as ever.

[LowRyter]

My EV gets about 35, at one time it got 40+. 

[lazlokovacs]

Damn i thought I was the young guy on a Calvin round here! Time marches on...

Re your bike- It could also be that a sensor has stopped working...

If, say, the O2 lamda sensor packs up then the bike defaults to a slightly rich setting...

Could well be the same for the engine temperature sensor and maybe even the air pressure sensor, or ambient temp sensor...

Basically the sensors send a message to the ECU to 'trim' the fuel injection times, if the ECU receives a wide open or closed signal it defaults to a slighter richer setting.

If the PO has uploaded his own map the it's likely that the O2 Lamda sensor has been disabled.

so probably not that...

The engine temperature sensors have been known to fail.

I would suggest getting Guzzidiag, that way you can read what the engine temp and all the sensors are saying, which should help you eliminate a few things.

Keep updating us

[delrod]

JC I've got a set of cables. Do you have a laptop to run guzzidiag

[Wayne Orwig]

What color in the spark plug ceramic?

BTW, That is very unlikely to be a 5.5 gallon tank. Guzzi lied if they said it is .

[Dave_NWTrophy]

One thing to also check - make sure your odometer is reading correctly.  The ITI gauges are known to strip out the odometer drive gears.  It will start with one tooth skipping, then slowly eat others.   My Cal Titanium started recording mileage at about 5-10% less than traveled before stopping completely.

Dave

[guzzisteve]

Air Filter-- GU30113600
Fuel filter --Mahle KL-145
Plugs-- Outer BPR6ES   Inner--- NGK PMR8B or CR8EKB(dual electrode)
Valves-- .006" exhaust  .004" intake

Throttle body cleaning can be done by sliding intake tube back into airbox & use bent tooth brush.

[JC85]

JC I've got a set of cables. Do you have a laptop to run guzzidiag

Awesome, I may see if I can borrow them. I've got an old laptop that has no memory whatsoever, but I can load and run Guzzidiag from a thumb drive on it.

[JC85]

Air Filter-- GU30113600
Fuel filter --Mahle KL-145
Plugs-- Outer BPR6ES   Inner--- NGK PMR8B or CR8EKB(dual electrode)
Valves-- .006" exhaust  .004" intake

Throttle body cleaning can be done by sliding intake tube back into airbox & use bent tooth brush.

Thank you! For my own personal knowledge, what's the purpose of having two different plugs for inner and outer?

[nc43bsa]

Thank you! For my own personal knowledge, what's the purpose of having two different plugs for inner and outer?

I haven't seen this particular engine, but probably because a smaller inner plug was required to fit in the restricted space.

[John A]

Keep an eye out for fuel leaks. These tanks can leak from edges or can develop cracks in the tunnel. You’d think it would be obvious, and eventually it will be but they can hide for awhile

[guzzisteve]

That's it, space. Use PMR's if you like to remove, clean, regap. The CK's are cheaper and toss away but long life.