Breva won’t take throttle

[Phil/TX]

I replaced the fuel lines du to a leaking plastic fitting, replaced fitting with a brass one. I rode to get gas, 10 mile ride, ran smoothly, and accelerated fine. Filled up 3.5 gal of premium, on the way home, suddenly would not run above 5000 rpm. When I turned the throttle at 5000, it bogs down. The valves have been set recently, new spark plugs, battery charged, just normal guzzi reactions.......... ..i didn’t even say anything bad to her?

[Zoom Zoom]

Your description makes me think partially plugged fuel filter or a kinked line preventing adequate flow.

Zz

[Phil/TX]

I’m thinking that also Zoom zoom, but why it ran so good going to the gas station, and so poor coming home?

[Kiwi_Roy]

When it bogs down, does it misfire?
That could be bad plug leads.
If it just loses power but doesn't miss I would agree plugged filter.
Perhaps your fresh gas wasn't so fresh after all.
Does the Breva have a plastic or metal tank?
Internal or External pump/filter?

[Phil/TX]

May have found the problem, battery low, when I got it back, I put the charger on it and it is still not charged after an hour. Fortunately I had the for sight to order a battery about three days ago. When the battery is charged, I will monitor the voltage till the new battery gets here. Then I will check the charging system .

[malik]

I know a deteriorating battery can cause all sorts of weird effects, and it's definitely worth trying a new one, but I'd be looking at the fuel, being the last change before the trouble. Here, down under, fuel composition is different, and I have found that at least one brand of premium doesn't work very well in the 2TB. I presume that the additives in it, designed for high performance auto FI systems are not appropriate for our simpler systems, even presuming the fuel itself is clean. Then, FWIW, I have found that there is no significant difference in using unleaded 91 or 95 either. But different countries, different fuels. I thought one feature of the Heron head design was tolerance for poor quality fuels.

Do note that I have found that balancing the throttle bodies improves performance and fuel consumption. How long is it since yours has been done? While doing that, you could check the operation of the TPS for flat spots. The one on my Classic had a flat spot between 3,400 & 4,000rpm. Replacing the TPS got rid of the persistent missing at around 4,000.

Good luck.

[GeorgiaGuzzi]

Sounds like there may be excessive water in the stations fuel. Too much water / bad gas acts like it’s really leaned out. As least in my experience.

[moto-uno]

  ^ +1 , Peter

[lucky phil]

I replaced the fuel lines du to a leaking plastic fitting, replaced fitting with a brass one. I rode to get gas, 10 mile ride, ran smoothly, and accelerated fine. Filled up 3.5 gal of premium, on the way home, suddenly would not run above 5000 rpm. When I turned the throttle at 5000, it bogs down. The valves have been set recently, new spark plugs, battery charged, just normal guzzi reactions.......... ..i didn’t even say anything bad to her?

If the battery doesn't change the symptoms dont discount a kinked breather hose under the tank, although from my experience with a V11 Sport it usually causes the tank to pressurise and expand you never know. The topped up tank means less air in the tank so less capability to cope with a blocked breather hose. Just postulating since you've had the tank off.

Ciao

[Phil/TX]

Charged the battery, starts and takes throttle, but only 13.5 volt at the battery. So I think I should get 14.4 voltes when running. So is it:
A) the battery?
B) voltage regulator?
C) Alternator?

[malik]

13.5 sounds fine to me.

[guzzisteve]

It's fine until it starts dropping on you, ride it & watch it.

[lucky phil]

Charged the battery, starts and takes throttle, but only 13.5 volt at the battery. So I think I should get 14.4 voltes when running. So is it:
A) the battery?
B) voltage regulator?
C) Alternator?

No you should be getting 14.2-14.4 range revving the engine. 13.5 reg output is low. I dont think it will be causing your issue though. Sounds like the reg to me. Check all the reg connections esp to the alt. I've just replaced mine with a EME unit.
If your bike has a hard wired headlight take it for a ride with the headlight fuse pulled or if not have the lights off. That battery voltage should be fine to run normally so it should rev out ok.

Ciao

[Muzz]

13.5 sounds fine to me.

A bit low for me Mal.  13.6 can be just a fully charged good battery.  1.4.2 at least and 14.4 better (on a fully charged battery.  It will be lower if battery voltage is low to start with.)

[Muzz]

Phil, you obviously have had the tank off to replace the fitting.  If not the filter, I would strongly suspect kinked lines.

When it has the limited revs, opening the gas cap and trying again could eliminate a kinked breather.

[lucky phil]

Phil, you obviously have had the tank off to replace the fitting.  If not the filter, I would strongly suspect kinked lines.

When it has the limited revs, opening the gas cap and trying again could eliminate a kinked breather.

Yes should work.

Ciao 

[Bisbonian]

Charged the battery, starts and takes throttle, but only 13.5 volt at the battery. So I think I should get 14.4 voltes when running. So is it:
A) the battery?
B) voltage regulator?
C) Alternator?

Are you using a standard voltmeter or the one built into the bike?
The one on the bike reads about a volt low in my experience.