phuel pump phizzle?

[Guest gooddog]

wel,l i got to use the $24 roadside assistance today. not that i'm exited about having to get a tow, but happy to have had the experience and report that it went without a hitch. actually a motorcycle trailer with slots for three bikes being pulled by an early 80's corolla wagon. he made a point to be there on time, was super careful with the bike and rushed through seattle traffic to get it to moto international before they closed. well worth the investment.

however....something fizzled out on me. i'd gone out for an expressway jaunt and to run some errands. after about an hour of riding, i'd stopped somewhere for about twenty minutes. when i hit the run switch to start it back up, the normal fuel pump noise sort of whined instead of whirred. as the ignition kicked in, the whine continued as it tried to rumble itself to life. it would idle horribly for about a minute, coughing and blowing back, then sputter out and die. upon last attempt, the rubber intake boot from the throttle body to the right cylinder came off in a cough pop.

i had to laugh to myself. as i rolled to the side of the rode, and was busy pulling the throttle body back onto the cylinder head, an old codger comes up to me and says,"now... that wouldn't happen to an old time bike!" he was only one of four different passersby who who stopped to marvel at my magestic goose. unfortunatly noone had any solid advice. anyway....i remember reading a thread sometime ago on the persistant whirr of the fuel pump, wondering what came of it.

any suggestions?

 

ray

[Admin Jaap]

Fuel pump problems? Justt a guess: a bad relay?

[al_roethlisberger]

Hard to say for sure, but if the pump was making the sound you describe... it sounds like it was pumping air, not fuel.

 

What year/model bike is this? Any chance you had a tank-suck condition, or a pre 2001/02 bike with the electric petcock that may have gone south? Just curious.

 

If it was running lean from this for a while before quitting completely, you could have overheated the head/intake, causing a detonation, blowing off the intake boot.

 

...it's just a theory

 

 

Let us know what you find out, as I'd like to hear the root-cause, and what failed.

 

al

[docc]

'02 LeMans ought to have a manual petcock. But it sure sounds like a fuel starvation. Not the dreaded 'vapor lock' in January?

[al_roethlisberger]

....probably not "vapor lock" but possibly tank-suck, or similar fuel starvation issue.

 

al

[Guest gooddog]

its an 02 lemans, now with 8300 miles on it. never had the vapor lock issue, and the tip over valve has long since been removed. i tried switching out the relays when it stalled out on me with no results. rest assured its usually the simple fixes, rather than serious mechanical failures.

the dip between 4 and 5k has been more pronounced as of recent, but i had thought that to be a result of its just running in and the colder, wetter weather. i have noticed a bit of a cough at steady throttle as of recent and have been hoping that a pc3 would solve some of these issues. i have been feeling guilty of pushing the limits of the rev range, punching it up to red and riding in the power range, usually 5 to 6k. why would you cruise at 4k where the throttle response is lagging? how much abuse can a guzzi take? i would imagine quite a bit.

micha at motoI was having issues with the diagnostic programs today so no news as of yet. we shall see.

 

thanks, ray

[Guest Buck]

wel,l i got to use the $24 roadside assistance today.  not that i'm exited about having to get a tow, but happy to have had  the experience and report that it went without a hitch.  actually a motorcycle trailer with slots for three bikes being pulled by an early 80's corolla wagon.  he made a point to be there on time, was super careful with the bike and rushed through seattle traffic to get it to moto international before they closed.  well worth the investment. 

    however....something fizzled out on me.  i'd gone out for an expressway jaunt and to run some errands.  after about an hour of riding, i'd stopped somewhere for about twenty minutes.  when i hit the run switch to start it back up, the normal fuel pump noise sort of whined instead of whirred.  as the ignition kicked in, the whine continued as it tried to rumble itself to life.  it would idle horribly for about a minute, coughing and blowing back, then sputter out and die.  upon last attempt, the rubber intake boot from the throttle body to the right cylinder came off in a cough pop.

      i had to laugh to myself.  as i rolled to the side of the rode, and was busy pulling the throttle body back onto the cylinder head, an old codger comes up to me and says,"now... that wouldn't happen to an old time bike!"  he was only one of four different passersby who  who stopped to marvel at my magestic goose.  unfortunatly noone had any solid advice.  anyway....i remember reading a thread sometime ago on the persistant whirr of the fuel pump, wondering what came of it.

any suggestions?

 

ray

Hi folks, haven't posted here in quite some time. Some of you might remember me as well as the ridiculous amount of problems I was having with my '02 Lemans, and the even more ridiculous problems I was having trying to get Moto Guzzi to help me. My '02 Lemans did exactly the same thing you are describing on multiple occasions when I was still riding it, even in cooler mid 50's temperatures. In my case it was definitely vapor lock. The dealer said they "richened" the mixture, but that alone told me they didn't understand the problem. Needless to say they've never been able to fix that problem, as well as a miriad of other issues.

 

As for my LeMans its just sitting in the garage nowadays. Seems like a terrible waste of a really fun bike. If only it were reliable. I still don't know what I'm going to do with it or how its all going to turn out. Anyone got a match I can borrow?

[al_roethlisberger]

Well, if it is "vapor lock," we've pretty much settled that it's now an easy fix to relocate the fuel-pump. My not-so-scientific results and Gio's quite scientific showed significant fuel and fuel-line temperature decreases after relocating the fuel-pump above the spine where the air-box was. I have also heard similarly good results with moving the pump "out front" as on the Centauro and Sport1100i bikes(after rerouting the fuel supply line well away from the cylinders).

 

The issue is the underslung fuel-pump, or on some model fuel-filter, hanging under the spine close to the left jug.

 

Gio was experiencing constant vapor lock issues, in a variety of weather, but from what I understand now has no issues.

 

Another sure-fire fix for rough idling, in my case, was to switch to Raceco valve lash specs.

 

al

[Guest captain nemo]

Raceco valve lash specs.

 

???? Please enlighten me; I missed this. What do you mean? And what are the specs?

[docc]

Al,

 

Didn't Gio do some heat shielding at the same time the pump was moved? One or the other or maybe both methods fxed his trouble. Guzzi science.

[al_roethlisberger]

Perhaps he should answer for himself, but yes I believe he heat-shielded the supply line and fuel pump/filter as I had done:

 

Relocating Fuel Pump Thread - See end for photos of my relocation/shielding

 

Here is his thread:

 

Vapor Lock Thread - See end for Gio's test results

 

al

 

 

P.S.

 

http://www.raceco.com/tech.html

 

 

Tappet clearances for two and four valve engines

 

Two valve engines

 

Tappet clearances for the Guzzi big twins should be set to 0.20mm for the inlet and 0.25mm for the exhaust.  This also applies to the "modern" Guzzis such as the Sport 1100, Cali 1100i and V11.  The factory settings for these bikes are 0.10mm and 0.15mm respectively, but this is to try and reduce engine noise to meet US emissions regulations.  With tappets set this tight the engines have trouble ticking over and running cleanly at low revs.

 

 

 

...which was exactly my problem. After last Winter's modifications, my bike REFUSED to idle, and no one at Moto Italiano could get it to run. Even after I asked about the tappet lash settings, and trying the Raceco specs, it was to no avail. Later Mike Stewart came over and we found the lash waaay too tight, even for factory settings, and then set the lash to Raceco specs. ...ran like a clock

 

*sigh* .... if the dealer would have only listened to me, they wouldn't have pulled all their hair out, and maybe they could have gotten their 2002 demo LeMans to idle correctly

[Gio]

Hi,

 

From the initial description given this sounds very much like vapour lock to me. I have experienced this problem in a variety of climate conditions - originally only during hot (~25 to 30c) days but after the airbox mods (snorkels removed, lid drilled) at much cooler (5 to 10c) conditions (even in the rain). The problem only occurs after a relatively short stop (during which it is theorised that heat soak occurs).

 

Here is a summary of my expts. I used a fixed route and measurement intervals/points to compare results (only a few of which I posted)

 

1. 706.002 map (mistral cans, stock x-over)

2. V11TomH map (much richer - ran a little cooler but still VL)

3. Added insulation to pump and pimary line - still VL

(4. moved temp sensor - no effect)

5. Re-located pump above spine, re-routed primary line under airbox to feed pump from the right side and filter out front - No VL observed since.

 

Personally I think the primary culprit is the stock location of the pump. I now have a manual petcock ready to install and so may re-route the primary fuel line as stock (ie from the left) to see if this makes any difference. Filter needs to stay out front (or elsewhere) if you wish to retain the airbox body (as I did).

 

Hope this helps. Let me know if you need any further details.

 

Gio

 

(2000 V11S)

[Guest gooddog]

gio,

after how many miles and what mods did you start experiencing the VP?

[al_roethlisberger]

Dunno about Gio, but my VL experience was immediately upon riding in high-altitude and high-temp(our Yosemite trip).... a couple months into ownership....

 

 

al

[Guest gooddog]

hmmm. well, i read through all the vapor lock threads, and i'd say thats probably it. however, this is the first time ithas reared itself in 8000 miles and 8 mos. of riding. i am curious as to why it would start now, especially with the stock bike(as of yet), and in the wintertime. i've definately riddin in hotter weather and in higher altitudes, with no episodes. i'm going down to pick up my bike at motoI in a few, then i'll know a little more on the symtoms and results.