Vespa Grande jetting is rich?.. hmmm I can't tell!

Matt Grantonic /

I know this has been answered all over but I just can't quite get it. I have a Vespa Grande with a Hi flow airbox and a Techno Circuit pipe...everything else is stock. The original jet was a 49. I purchased a bunch of jets and started with a 63 hoping it would 4 stroke then I would work down from there. problem is, it wont 4 stroke and from what I understand a 63 should be rich for this set up. I did a plug chop with a new plug and it still looks shinny with nothing to read that I can tell. It runs fine and goes about 34mph on the flats...should I mess with it? Oil is leaking from the exhaust port and it wasn't with the original pipe. Any thought? Thanks, Matt

Re: Vespa Grande jetting is rich?.. hmmm I can't tell!

***VANILLA BLUNDER*** /

i have a 57 in my kitted engine, try a 52

Re: Vespa Grande jetting is rich?.. hmmm I can't tell!

Matt Grantonic Wrote:

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> problem is, it wont 4

> stroke and from what I understand a 63 should be

> rich for this set up.

what works with 1 setup won't work on another.

while wasting money, it's cheaper in the long run to get it to 4 stroke.

i say this because you're not mentioning a temp gauge for accuracy.

upjet until you can confidently say it's too rich, then go back down a few sizes.

see if this link is helpful to you: HFFS

not going to go into the multiple reasons you need a bigger jet then expected.

Re: Vespa Grande jetting is rich?.. hmmm I can't tell!

if you have a leak at the exhaust, it will suck in air and make you lean (need a big jet)

fix the exhaust leak first

make sure there is no leak at the carb second, big problem on vespas

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