engine hot = start problems

[Guest Ivan Priem]

Hi,

 

My name is Ivan Priem and I'm riding Guzzi since the very start (1st bike Lemans II, then Lemans IV and i have now a Daytona and a V11 Sport).

 

I have bought a V11 sport in February (green 2000 model). "It" had relais problems since the very start. My dealer in Belgium adjusted the relais' (now Bosch) and removed it downwards because the sadlle was iritating the 4 relais'. Problem solved. However, after a big trip to the French Pyrenees (now problems at all) and after a maintenance at the dealer (now 22.000kms) a new problem appears. Cold engine starts are not a big problem. But when the engine is hot and you leave for amount 15 minutes there will be a big chance that the fuel pump will not work (you all know the sound bzzzzzzzzzzzzzz). If you hit the big gray relais it started, are when you are squeezing in the rubber fuel pipes it started... very curious isn't it. Vapor locks are possible but a dealer in the German part of Belgium tells me that the relais box is shit and should be replaced by normal fueses like we all know.

Does anyone has experience with the problem. All my friends on Japanese bikes having great fun about my electronical problems...

[Guest Jaap]

If you replace the Siemens relais for Bosch ones (TLM Nijmegen has them on stock) your problem will probably be solved. It's a common problem on V11's

 

Good luck

Jaap

[Guest Ivan Priem]

If you replace the Siemens relais for Bosch ones (TLM Nijmegen has them on stock) your problem will probably be solved. It's a common problem on V11's

 

Good luck

Jaap

This has already been replaced but still...

My dealer has disconnect the start interruptor of the clutch, meaby something went wrong ???

[al_roethlisberger]

I think this is the common "Vapor Lock" issue reported on many 2000 V11 Sports, and some later models in hot climates. There have been several causes attributed, but most folks have found that the fuel supply line on the 2000s rests too close to the left head(sometimes touching), and after a long ride, then sitting, the fuel boils in the line making the pump ineffectual until the bike/head cools down.

 

The fix?? ...let the bike stand for 15-30 minutes to cool..... or a precautionary tactic.... move/mount/shield the fuel-line away from the head. The 2000+ bikes have the line covered in a metal braid, and installed a couple inches away. I moved my lines further away on my 2002, both on the fuel supply and FI return line, and so far(knock on wood) no "Vapor Lock".

 

The other big known issues with the 2000 models are certainly replacing the relays.

 

One final suspect on pre-2003 V11 Sport/LeMans is the fuel pump that is located above the left head. This is also exposed to some significant heat, although it is several inches away. Several folks have mentioned and thought about making a heat-sheild for it, but no one has yet confirmed that this problem is actually caused by overheating the pump/fuel, where some people have seem benefits from moving/shielding their fuel supply line. Certainly a well-made aluminum sheid for the pump "wouldn't hurt" though The 2003's will have an in-tank pump, so this should be a non-issue for them.

 

...as an aside, I wonder how much fuel capacity will be lost with the in-tank pump on the 2003's... hrmm...

 

I think Guzzi would really do the LeMans a favor if they could squeeze another useable gallon out of the tank.

 

al

 

 

P.S.

 

...oh, and as another "aside" since I'm thinking about fuel. I wonder why (and if it would be hard) Guzzi didn't include some sort of "balance tube" for the tank so we wouldn't waste fuel or have to "wiggle" the bike to get to fuel stuck on the right side of the frame/tank over to the left where the petcock/tap is. Seems silly. I wonder how hard it would be to pierce the tank and make one yourself... that is reliable and durable that is... esp given that the tank it plastic. Dunno if it would even be worth doing.

 

P.P.S.

 

.......ok, and one more "aside". I still haven't done my "run dry" test yet.... I know, I know... been talking about for months

 

But, anyone have any reliable data yet on how much fuel is left(Gallons/Liters) after our low-fuel light comes on? I think we all agree that ~130 miles is where it lights, but as far as I know, none of us know for sure how much fuel is actually available after that. Again, I'll be testing it personally at some point, but I just keep forgetting!

 

My mileage has gotten a bit better, and is in the 36-37MPG range now instead of pegged at 35. I guess the engine is loosening up

 

I still want 40 though!

[Guest Scura Owner]

Al-My light starts to flicker after 4 gallons have been used. Usually between 160 to 180 miles in my case. My best gas mileage to date has been 46mpg. I have gone over 220 miles and and still had over .5 gallons left in the tank.

[Guest ivan]

Thanks for the answer. It could be a Vapor Lock because, and this is very strange, the fuel pump begin to work if you play around with the rubber fuel pipe by squeezing in it. My friends have a laugh because I had to squeeze 3 times because the engine starts (fuel pump).

 

About fuel capacitiy, it will be difficult to measure this because injected motorcycles will have a safety of ± 1/2 liter of fuel witch cannot be used but it will be in the tank. This prevension-methode will avoid damage in the injection system when you drive the Guzzi "dry".

 

I hope this can help you.

All the best and keep it save.

[Guest v11eric]

Ivan,

Whats the sence off having a half ltr left when the bike runs dry and stalls???

I one's ran my centauro dry and there I could tank 17ltr were they gave 19ltr as capacity, be carefull it could be a long walk to a gasstation.

 

Eric

 

01 V11 Lemans

[Guest ivan]

Well, the fuel line of an injector may not be run dry (could damage the electronical system) but don't worry, their will be some unuseful fuel left in the tank.

 

About technical figures, I have an official technical chart of the Guzzi factory of my Daytona, 23 Liters it tell's me. After pushing it to the gas station i could tank about 18.5 liter, there you are.

 

Best regards,

[callison]

I don't think that running out of fuel will damage the injectors or the electronics. With no fuel there isn't any point in continuing cranking the engine or anything, so the time firing the injectors while dry would be minimal. In any event, I don't think the injectors rely on the fuel for cooling or lubrication. On cars, the fuel pump is in the tank to keep the pump from burning up. For this reason, you would not want to run the bike dry, but again, if the engine quits from lack of fuel, you're going to turn off the key anyway. And push...

 

The 2003 V11 Sports apparently have the fuel pump in the tank. Probably to prevent vapor lock. I wonder how much tank volume was lost in an already undersized tank?

[Guest John Sears]

Hey Scura Owner, That's encouraging that you're getting such great mileage! Just wondering: how many miles are on your odometer?

 

I'm getting about 35mpg, with around 2600 mi on my '01 V11S with cf cans (think they're Mistral, but no brand on them), K&N pods, and PC III.

 

John S.

[Guest IanJ]

The reason they don't want the fuel injection (FI) system to run dry is that the pump is incapable of priming itself. At least, that's my understanding on FI cars and on the FI system on my family's diesel tractor -- if you run it out of diesel, you get to spend a happy half hour bleeding the fuel system of air bubbles before it'll start again. I assume they force the bike to quit with extra fuel in the tank so that you don't have to bleed the system before it'll start again, which would be a nearly impossible task on the road. Adding gas, on the other hand, is a simple fix, and I agree with their logic in leaving us the simpler rather than more complex solution.

 

I'm not sure that's the exact reasoning on a FI motorcycle, but it makes sense.

[Guest jlburgess]

Ivan said: It could be a Vapor Lock because, and this is very strange, the fuel pump begin to work if you play around with the rubber fuel pipe by squeezing in it.

 

I'm wondering if the problem is actually the fuel pump itself Ivan. If you really had a vapor lock I doubt this would fix it. Perhaps an intermittent electrical problem or suction leak on the pump intake side in being cured by you touching the hose??? There's probably a one way check valve somewhere in the pump too that could be leaking. Just a guess.

[al_roethlisberger]

Well, now I can officially join the "vapor lock" club... and as if I weren't convinced before(I was)... I am 100% convinced now that this is totally a heat-related issue with the fuel-line/pump after riding in very hot conditions and not quite giving the bike enough time to fully radiate the heat away.... causing the heat to "soak" into the pump/line as the heads radiate.

 

Scenario: This weekend, we took a ride up to Yosemite, and up at Glacier Point(~4000ft elevation) after climbing the mountains in ~100F degree weather, we stopped for about 20 minutes to take-in the view. Upon returning to my bike, I tried to start it, and although it fired off at first, it stumbled badly then quit, and I could hear the fuel-pump whirring a bit too much with the engine eventually dying.

 

Keeping in mind that I tried this several times over the next 10 minutes, and that the bike had been running extremely well all day, and it was hot as "heck" outside.... I figured this must be the "vapor lock" issue. So, since I knew it was cooler down the road in the trees, and if I could get some air flowing over the engine it would cool down more quickly, I just sent the rest of the group ahead and then coasted down the mountain for about 100 yards, and VROOM... it started right up!

 

But what's also interesting is that the following day we rode in some slightly warmer weather, stopped nowhere near shade

(were in the desert), left the bike to sit an even shorter time, but I never encountered this problem again?? I can only guess that a combination of heat and altitude/low-atsmospheric-pressure conspired to make this happen, and it was pretty mild as the bike "almost" ran.... just not quite. So maybe my efforts to move the lines further away from the heads, etc... have helped, but extreme conditions make it slightly vulnerable.

 

Anyway, so, it's not something I'm too terribly worried about as it never happened again, and isn't anything permanently disabling, but I might entertain making a heat-sheild for the pump this Winter when I work on a few other projects.

 

...oh, and completely as an aside, after putting on 1000+ miles in two days, I've really grown to appreciate that "pad" on top of the LeMans tank

 

al

[al_roethlisberger]

BTW, something someone posted to the MGCL list....

 

Heat Sheild Tape at JC Whitney

 

 

Perhaps this could be wrapped around the fuel supply line for some additional "insurance". I heard that one fella in Canada?? moved his fuel-pump to the rear of the bike, without much affect. So perhaps the heat is getting to the fuel-line more than the pump?? It's hard to say without additional experimentation.

 

But the tape above might be an easy bit of extra protection

 

al

[Guest voigtstr]

Hi I have a burgundy and grey Le Mans ( pics at http://users.bigpond.net.au/voigtstr ).

 

Yesterday I filled the bike with premium unleaded and then took it for about a 30 minute ride around St Kilda (Melbourne Australia). I was accelerating fairly aggressively taking the revs up to about 6 (it only has about 2500 Km's on the clock). I was noticing that if I gave the bike full throttle when in low revs still I was getting a lot of pinging. The temperature was about 25 degrees celcius on the day. I was doing a lot of short bursts of full throttle and then sitting at traffic lights and taking off again. When I got the bike home I noticed that the cylinder heads were radiating a lot of heat. Also it looks like the extra heat had encouraged an oil leak at the bottom rear of the engine and some drips had found their way onto where the pipes join up under the bike and causing a little bit of smoke.

 

In retrospect I think the pinging is what caused the extra heat (and the extra heat was causing more pinging?) basically from thrashing the bike (well not going over 6000 revs but riding the bike very aggresively).

 

When I tried to start the bike about 45 minutes later the bike was coughing and spluttering and sounded like it was backfiring through the intakes. It would stall rather than idle and would cough and splutter if reved to 3000 or so.

 

After reading here I conclude that this is vapour lock caused by the fuel lines getting to hot.

 

Today when I started the bike it idled perfectly.

 

Thoughts... perhaps the pinging was caused by fuel that might have been only about 94-96 ron and not 98 like some of the fuel companies produce here in Australia. Would a fuel additive to increase octane rating stop this pinging.

 

Am I corrent in thinking that the pinging caused by lower octane fuel would cause the bike to run hotter, and that the hotter the bike gets the more pinging would occur?