As tank gets.empty performance boosts

My bravo is a beauty but a slow beauty...I'm always wondering should I downjet to keep it in the pipe to get higher rpms. Yesterday on the way over to my buddy's garage I was

Re: As tank gets.empty performance boosts

Please , continue the story . ;)

Re: As tank gets.empty performance boosts

Dirty30 Dillon /

> P D Wrote:

> -------------------------------------------------------

> Please , continue the story . ;)

Re: As tank gets.empty performance boosts

He just was, now he is

Re: As tank gets.empty performance boosts

Mike Scouty McScoutington /

After seeing his profile pic I would say "he was" seems accurate.

Re: As tank gets.empty performance boosts

Marc loves to run lean then when

Re: As tank gets.empty performance boosts

What had happened was

Re: As tank gets.empty performance boosts

classic carl jepsen /

What's the deal with Supernurbs? Is that to use nurbs or is it a feature that turns into nurbs? Or does it have nothing to do with actual nurbs and is kind of like nano nurbs?

Re: As tank gets.empty performance boosts

Jesse Nordlander /

Despite the cutoff, the title brings some logic to fuel pressure being higher with a full tank. Something like 2psi/ft. I doubt it would ever be actually noticable.

Re: As tank gets.empty performance boosts

♣Slew Foot♣ /

Maybe the gas cap vent is clogged and when it gets too high It burps and then it runs great.

Re: As tank gets.empty performance boosts

Motors run best right before disaster screech

Re: As tank gets.empty performance boosts

As the carb runs dry the mixture in the engine changes to be lean with the starvation of fuel. The engine burns the oxygenated fuel better which does make your engine run a little more peppy, but without oil it will quickly lead to failure.

Running out of fuel is a good way to seize your engine.

Silly two strokes, why cant running out of fuel just mean the bike will stop rather than possibly kill itself.

Re: As tank gets.empty performance boosts

> pat splat Wrote:

> -------------------------------------------------------

> Motors run best right before disaster screech

Man, ain't that the truth, once I only had to think "blimey it's running like stink" and I chucked a rod

Re: As tank gets.empty performance boosts

♣Slew Foot♣ /

I had one rape a steep hill then 2 blocks away at a light hard seize new kit.

Timing was off a tad.

Re: As tank gets.empty performance boosts

Lean is mean, as the saying goes

Re: As tank gets.empty performance boosts

I've got one moped that just refuses to run true on any air filter. Couldn't get it running right and then when I was about to run out of fuel it suddenly got this boost of power you describe.

Took the air filter off at that point and that's when the ped started running an absolute dream. I have since jetted the shit out of it, tried 4 or 5 different types of air filter (mesh, foam, filter box, you name it). Whatever I do, whenever it's set up right using an air filter it just doesn't run as well as it should. Weak and joyless.

I now just run a velocity stack in stead of a filter and it is one of the best running peds I've ever owned in it's current state.

Not saying this is what you should do too, as this is usually just solved with proper jetting and fine tuning. But your opening statement reminded me of this case.

Re: As tank gets.empty performance boosts

> Roy De Koe Wrote:

> -------------------------------------------------------

> I've got one moped that just refuses to run true on any air filter.

> Couldn't get it running right and then when I was about to run out of

> fuel it suddenly got this boost of power you describe.

>

> Took the air filter off at that point and that's when the ped started

> running an absolute dream. I have since jetted the shit out of it, tried

> 4 or 5 different types of air filter (mesh, foam, filter box, you name

> it). Whatever I do, whenever it's set up right using an air filter it

> just doesn't run as well as it should. Weak and joyless.

>

> I now just run a velocity stack in stead of a filter and it is one of

> the best running peds I've ever owned in it's current state.

>

> Not saying this is what you should do too, as this is usually just

> solved with proper jetting and fine tuning. But your opening statement

> reminded me of this case.

Have you tried downjetting until it runs fine with the filter?

Re: As tank gets.empty performance boosts

I was/am aware that as a bike runs out of fuel the mix definitely often leans out...what I experienced is that the motor momentarily performed the way it was supposed to...it finally got far enough up onto the rpms to do what a proper vespa build with an anticipato crank and a polini 43 mm kit ( btw graham motzig actually built the motor for me ) should do...so yes I'm going to downjet , keep a temp.gauge on it and see if I drop a few jet sizes if all along it's basically in a rich bog.. so it's on my to do list.

Re: As tank gets.empty performance boosts

> Nick MBC Wrote:

> -------------------------------------------------------

> > Roy De Koe Wrote:

>

> > -------------------------------------------------------

>

> > I've got one moped that just refuses to run true on any air filter.

> Have you tried downjetting until it runs fine with the filter?

Yup, as stated, with several types of filters as well. It’ll run ‘fine’ with a filter on it. The difference in power and speed is just too big with any of them versus the velocity stack for example. The top speed alone drops by about 8 miles an hour when jetted properly to take a filter.

Re: As tank gets.empty performance boosts

They usually runs a lot better all of a sudden right before they seize and leave you in super sadsville

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