Indications of a bad fuel pump

[Steve G.]

So I go for a nice ride a few days ago, the bike running very nice. A short stop to sip a juice, and that old problem creeps up again. When it's hot, trying to make it run at anything other than idle, and it pops back and often stalls. If left for a couple hrs to cool, it starts and runs nicely. So I thought this was a vapour lock problem.

Well, this time I had to get back home soon, so did some side of the road fixing. first off, I noticed the fuel pump was making a different sound when it ramped up when you turn the key on, and that there was a gurgling sound around the hose that goes to the tank on the left side, with the key on. Turn the key off and the gurgling stopped. So with the key off, I loosened the hose there, and a spray of gas emitted from the loose hose, followed by probably 3 minutes of air. After the air has stopped, I tightened the clamp up, and the bike started as if no problem, and the fuel pump made it's usual ramp up sound, and no gurgling anywhere.

The nice fellow from MPH was offering his thoughts to me about this problem I'm having, down in Ojai, CA last weekend during the Laverda Rally. There he mentioned the possibility of a bad fuel pump.

Soooo, how is the air getting in there? Is this air making an otherwise good fuel pump cavitate, unable to pump? Would'nt the fuel return in the fuel delivery system return the air into the gas tank at some point quite soon?

Any other thoughts?

Ciao, Steve G.

[al_roethlisberger]

....sounds like classic vapor lock to me, the "air" being vaporized gas

 

 

Although, yes, technically if air is getting into the line/pump somehow, you would have similar symptoms.

 

al

[beauchemin]

The nice fellow from MPH was offering his thoughts to me about this problem I'm having, down in Ojai, CA last weekend during the Laverda Rally.

50590[/snapback]

 

 

What!? You rode your V11 Sport to the Laverda rally instead of your Jota? Are you getting soft?

[Mike Stewart]

.

The nice fellow from MPH was offering his thoughts to me about this problem I'm having, down in Ojai, CA last weekend during the Laverda Rally. There he mentioned the possibility of a bad fuel pump.

                                                                                Ciao, Steve G.

50590[/snapback]

 

 

Steve,

 

Did you happen to go to Guy Websters Italian bike collection while in Ojai?

 

Mike

[callison]

Back when the vapor lock thread was going full swing, I changed out my electric fuel petcock for the manual type when the electric one quit working. The electric one has an angle on the hose fitting of about 45 degrees where the manual one is ninety degrees from the body. I didn't re-route the hose and that put a more severe bend on the fuel line coming out of the petcock. Everything was normal until the engine area warmed up when the fuel line warmed up and softened a bit, then the fuel line collapsed at the additional bend and cut off the fuel. I re-routed the fuel line to avoid the kinking area and everthing was fine. Eventually, I re-built the electric petcock and returned to the original configuration.

[Steve G.]

Hi guys,

Getting soft is not yet in my vocabulary Chris. Indeed I rode my Laverda Jota to the Laverda rally. And back. When Pierro Laverda [THE guy] found out we had ridden our old tractors down there, he was quite emotional about it. So impressed that in absence of no long distance award for non-trailer queens, he and his son Giovanni awarded my bike best 180 deg triple and Robert's Mirage second best 180 triple, even though they were quite soiled looking from bugs and rain.

We did spend time at Guy Webster's place, absolutely outstanding. In fact Ojai has a bunch of collections hidden around. Funny what you will find in an area where there is a HUGE amount of money happening, and passionate enthusiasts who care about historic machinery. As well as Guy's collection, Mike Taggart has a warehouse in Ojai full of Italian and English classics. You know you are reaching motorcycle overload when 7 BSA Gold Stars in a row barely garner a second look, after checking out over 10 MV Agustas, some factory race bikes! The works Jaguar C type, and D type race cars, ho hum! Oh, and the son of the original importer of Triumph in America, Johnston Motors, who kindly rolled his collection out into the tarmac at Santa Monica Airport. Mind numbing works bikes, maybe 40 odd. The Solvang motorcycle collection[ with Rolly Free's famous Bonneville salt flats Vincent], The Otis Chandler collection, and of course hosts of the rally Allan Chalk and Bob Andren, who combined appear to have over 65 machines of very high regard.

Helicopter Jim stopped by to introduce himself, when the rally moved out to Willow Spring Raceway for the last 2 days. Also a Laverda owner, and SFC 750, regarded as one of the most valuable and collectable bikes ever made. Of course the action on the track was noteworthy only because a works MV triple was screeming around, oh and a Britten was sonic booming around the track.

The whole rally was very special, in fact people there knew history was being experienced as Jack MacCormick walked into the banquet hall, and met Pierro Laverda in a huge greeting. What blew us away was Pierro asking us if he and Jack could sit down to dinner with us, saying he wanted to sit with his new Canadian friends. Wow! Later at the track, Pierro offered advice on my bike, saying that when he was testing my bike in early '81, along with factory test riders, he noted the bike would want to "fly like an airplane" at speeds over 125mph. He found that if the fairing was set forward 3 degrees, all would be good, and said I should do the same, as he didn't want to lose his new buddy, while patting me on the back. Personal advice from one of the two guys who made the bike. Yup, pretty damn cool.

Bob and Allan did good, they were responsible for this historic gathering.

The fellow who runs MPH in Houston showed up on a buddies Moto Guzzi Quota, and this is where I took advantage of the opportunity to talk to an expert on the V11 Sport.

Ciao, Steve G.

[jrt]

Wow, that is a one cool story, Steve!

 

 

Back to your original post- what do you mean by "3 minutes of air"? You had the ignition on so the pump was pumping air for 3 minutes, or was this just built-up pressure?

[beauchemin]

Wow Steve! It sounds like I missed an unforgettable rally. Unfortunately I was moving house that weekend... can you bring pictures to Wolfgang's place in July?

 

CB

[Steve G.]

Yeah, the roadside fix for the apparent vapour lock was done with the ignition off. There was quite a bit of pressure built up, and I was very carefull to let off the gasoline spitting out gradually, but when the residual gas was gone, the pressure build up was air, or as Al correctly mentioned, vapourized gasoline. This "hissing" of air lasted at least 2 minutes, then simply stopped. So I tightened up the hose, turned the ignition on, and the fuel pump sounded as it should, or at least how it has sounded since new. It was then that the bike started up just fine.

I was talking to the fine folks at Valley Moto Guzzi today, in particular Gord the head wrench over there. Great guy! He gave me advice that I will be doing. He said to wrap heat deflecting aluminium wrap much like under the fuel tank, around the external pump, and this will cure the heat vapour problem.

Ciao, Steve G.

[luhbo]

Hi guys,

Getting soft is not yet in my vocabulary Chris. Indeed I rode my Laverda Jota to the Laverda rally. And back. When Pierro Laverda [THE guy] found out we had ridden our old tractors down there, he was quite emotional about it. So impressed that in absence of no long distance award for non-trailer queens, he and his son Giovanni awarded my bike best 180 deg triple and Robert's Mirage second best 180 triple, even though they were quite soiled looking from bugs and rain. ....

50811[/snapback]

 

Meeting members of the Laverda family is always a very enriching experience. At this meeting he had the V6 with him and an original 750SFC also.

 

http://www.motalia.de/laverda-treffen_bild_1.html

 

Besides telling very interesting stories about the developement of this ship and lots of sometimes quite amusing episodes from racing it, he let the bike scream quite liberally throughout the night. He really made courses how to treat it. "You must pull up and then let the throttle snap, that's important....No, no, no, wrong, look, this way!" woah, woAH, WOAAAAHHHH! "OK, try again!" The V6 at 6000 min-1 in full endurance trim at 2 o'clock in the night!!

People were much too carefull with this icone, but for him it was not a museum inventory, maybe he himself was trying to get or to keep his memories alive.

 

I can say the same, great to get reminded to that.

 

Hubert