Modern Vespa

Update: it's already not good My new throttle body doesn't rattle. UPDATED: dying 🤬🤬🤬 (Post 2653133)

Huh what?

History (this is number 3):

First
idle went to hell. rattles. shaft moves a bit in/out very distinct gap around butterfly

Second
Installation: idle perfect. don't know if rattled. no shaft movement. no gap around butterfly
Now: same as first. (bad idle, rattles, shaft moves, butterfly gap).

Third
same as second at installation (no rattle) and presumably same as first when brand new.


So why the post? I only noticed the rattle in 1st+2nd recently when reinspecting before ordering the 3rd.


Strong suspicion that the rattle is something on the end of the shaft that is hidden behind the ecu that broke / came off (eg a nut worked itself loose) and since the return spring on the shaft has a slight outward pressure* this led to the shafting pushing outwards so the butterfly rubs against the side of the barrel giving very visible wear / gap.

So why the rattle? Was there missing loctite on the nut on the hidden end of the shaft? was there a plastic thingy that cracked and broke in there? Was the 60C air temp reported by the ecu for long periods related to this failure?

So ... the new one is slightly different. Previous were both 32M4/B and this new one is 32M4/C which I interpret as a hardware revision. Definitely a different cast mould (see pic). Also this one came with a white silicon/rubber cover of the ecu (have seen this on pics of other peoples hpe). Might be more robust if I'm lucky.

I'm currently a bit scared to install the new until I mount a fan in the engine bay. I am also currently testing a crude bracket to keep inwards pressure on the shaft on the 2nd


* I know the spring has outward pressure as I dismantled this part of the first.

crosslinks:
Saw tooth idle [SOLVED - worn throttle body]
T̶h̶i̶n̶k̶ I've a̶l̶m̶o̶s̶t̶ worn out another throttle body

It's natural to assume that the 'C' varient is an upgrade on the 'B' version, that and given the later manufacturing date. I've never heard of this modification before. Are you suggesting the failures of 1 & 2 are down to over-heating?

Maybe maybe. If the *air* temp reported is 60C then the temp in other parts of the ecu / throttle body that are more enclosed such as the location of where i think the rattle is could be even higher. Repeated expansion and contraction of parts in that area ...

Italy regularly sees 40c+ Summers, so I doubt they would of designed a product that struggles with heat.

Completely different setup, but my previous Elettrica had virtually no power in under 10c, but would unleash its full power non stop at 35c+, so the lithium battery insulation was clearly designed to cope with heat rather than the cold.

I would be more inclined to think it's dust / dirt particles getting through your air filter and wearing the internals.

What type of air filter are you running? Do you change it more often with your off-road riding?

What warranty do the parts have?

nah.

air temp: the air intake on australian bike is different to european and american. it has a long snorkle through the engine bay before entering the airbox unlike euro/usa where it's sucked directly into the airbox from near the cvt. the snorkle gets very hot and heats the air well before it has even reached the airbox. So don't compare the ambient air temp between when it's a differnt system. it's gonna be hotter in my scoot when in the same ambient temp.

trust piaggio design? Nah. the poorly designed start of the snorkel sucked part of it's air from the engine bay pulling in hot air and dust. I blocked the gaps with foam and now it doesn't (did this years ago). (plus shite load of other unrelated fails in the design of the bike)

dust: dust ain't gonna get into the enclosed area that is rattling so nope it won't have caused that fail. plus once I did the above mod it reduced the dust in the paper filter massively which I do change very frequently anyway (several thou kms)

little extra: I'm thinking I might remove the ecu in my first unit (probably requiring whipping out the Dremel) so I can see the end of the shaft and the rattle. maybe. the act of doing so my make it not obvious which bit was f'd ... trying to predict before acting

handy pic of the miug3 internals which I suspect will be same layout as the g4. note the g4 does not have that cover that appears to be removable instead that area is filed with black epoxy stuff

look at the green tps bit - that's where I suspect the rattle is (hard to tell exactly of course). This is the end of the shaft that is incorrectly moving. (and yes the tps is working). and what is that yellow pipe there?

With a 90° bend on one end, it's probably to demonstrate that there's a passageway leading between the throttle body and the stepper motor, but why it's shown lying in this location on the diagram, I really don't know.

Installing fans in GTS engine bay

btw here's pics of the spring (removed from old throttle body) that show the springiness.

not crazy but it's enough that when you undo the nut the black pulley does push out

update:

🤬🤬🤬

1200km* and crap load of movement with flap open. none yet with it closed but it's only a matter of time 🤬

But no rattle?

* didn't get around to installing it until late october

It's obviously the vibrations from those fans you installed doing the damage. Maybe.

You don't think it's the multiple trees I had to wrestle last weekend?

in this video you can see it move outwards as the butterfly is opened and then me pushing it back in again.

need to contrive a way to keep it in so it stops sliding on the side of the barrel which will over time result in gap like the previous two tb.

And my crude "bracket" (bent bit of wire) that reduces the outwards movement.

"but that'll wear on the throttle cable". Cables are cheaper than throttle bodies.