Re: Deristricting Vespa variator

i mean, jet where ever its happy but if you're over a 62 you might want to look hard for an air leak. decomp is pretty common on these.

Re: Deristricting Vespa variator

Yeah... I'm thinking I went overboard upsetting. I'm trying to learn too fast, but learning from my mistakes. The lowest in my kit is a 60, the weather here's been crappy. So I gotta wait for nice day to work. Rejet, New plug, and plug chop coming up.

Re: Deristricting Vespa variator

I put a lot of trust in your expertise, Graham. I don't know why mine jetted at 69, but I worked my way up to it. Maybe I need to lap my decomp. I was super green when I put my Bravo together, and maybe a little paranoid and didn't want to seize. I worked my way up in odd sizes Un till it four stroked, then down a size. It runs great, and tops out at 38 so I left it. Haven't touched it since. I'll delve into it deeper when it's turn comes up on the bench.

Re: Deristricting Vespa variator

what weight or drill bit size do people recommend?

Re: Deristricting Vespa variator

38 on a stock bravo is flying my man! great job. if its going 38 with that jetting don't touch anything and keep praying to whatever deity got you there.

Re: Deristricting Vespa variator

That wasn't gps or anything, just speedometer reading. But it felt like it was flying. The cylinder is stock, but I have a Proma Circuit pipe, 13.13 carb, and Polini variator. I lied, and said I haven't touched it since, but I forgot I have since changed contra spring to white, and changed weights to help on hills a bit, so only does 35 currently. Any faster is scary on a Bravo, for me. I can't see that fast.

This thing has always seemed pretty quick, for some reason. (edited)

Re: Deristricting Vespa variator

Have you redistricted your subframe? I didn't read that you had. Doing this can give you more options instead of buying different belts.

Knock off one of the soft aluminum rivits to expose the slotted motor mount hole allowing the motor to slide back and forth.

Re: Deristricting Vespa variator

No I haven't Cheetachrome. Gonna do that plug chop I totally forgot about first. I'm gonna WIKI the rivet tutorial first. 8)

Re: Deristricting Vespa variator

Your jetting is crazy graham.

For me, my general jetting for vespa (+3/-3 ) is:

Stock: 45

Stock w/ pipe : 60

43mm kit: 68

After that it gets weird

Re: Deristricting Vespa variator

Okay.. today I changed out the jet from #68 to # 64 ( I thought it was a #69). Went for a run. It didn't bog down or cut out when stopped. Tick over speed is good. Ordered some weights from Treats, and ill experiment with them. It's seems I'm getting the hang it.

Re: Deristricting Vespa variator

EH 📣FCC of the QCB /

> Graham Motzing Wrote:

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

> 67 seems crazy huge on a stock cylinder, seems pretty big even for a

> kit, i am at a 60 right now and probably need to go to a 56 or 58 on

> stock /ported proma circuit

65 jet on a 13:13 with Simo pipe and ported regular Polini 64cc Kit.

Re: Deristricting Vespa variator

43mm kits with 13:13, pipe, mazzi, no air leaks like the 66main that comes stock in the Sha 4 me.

Re: Deristricting Vespa variator

haha ok, as much as i hate talking jetting on line, vespa jetting for me has always been super predictable on these ultra basic setups. I also run malossi or mod stock air filters and drill my own carbs and open up the holes in the emuslsion tube/ bevel the slide to get them running perfecto.

43 dr or malossi, cut crank, proma circuit, 13 drilled SHA, air filter: 66 or 68

- same as above with calibratta- 70 or 72

Stock cylinder with pipe, drilled 13: 58- 62.

I just dug into that one i said needed to go down from a 60... its actually got a 62 and a leaky float needle, so 62 or 60 might be dead on.

i'm seeing a lot of people posting similar numbers so i don't think its just this pure, fresh, wisconsin air.

Re: Deristricting Vespa variator

okay, those numbers seem a lot more in line with my jetting compared to what you posted previously.

my bravo is STILL lean at 106- i need to buy bigger jets. and im not chasing an air leak.

speed case/OG deps with 30mm flange/ janus pipe/ 19pgbg

Re: Deristricting Vespa variator

yeah the only reason i think its even worth discussing is just because time after time, i build these basic-ass cookie cutter setups and they always run exactly the same, same jets same timing etc. None of the other bikes i build are like that, I've probably built over 20 (30? who knows)) puch motors and no two of them were exactly the same combo or the same tuning. Even when i build stock ported puchs they all run slightly different.

So many people have head/base gasket air leaks on these engines so i feel like if you are off those numbers i posted, its time to bust you yer sherlock holmes bubble pipe and go sleuthing for air leaks!

Re: Deristricting Vespa variator

Yeah, mines def screwed up somewhere then, if I'm jetted @ 69. I'm gonna have to look into that, and find my air leak.

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