Re: Vespa bravo refuses to idle

. And tomorrow I'll

> switch to ethanol free gas and stop using regular gas.

not super necessary but is more important is adding 2 stroke oil.

The points cam not fitting well tells me its not stock, the ones i've seen are regular metal, no chrome, not painted and no mfg stamp, and they are finely machined to just slightly push fit. So the install order goes woodruff, slide spring washer down and then slide down cam, then flywheel. I suggest sourcing another one new or used points cam and woodruff. You did change the one crank seal correct?

Re: Vespa bravo refuses to idle

Andrew Snowberger /

I did change the crank seal, and I did use a kinetic cam collar. The one stamped GKM is supposed to be a vespa part. Hey wait, the spring washer goes between the crank seal and the cam collar? Thought the washer went between the flywheel and the cam collar. Is that what's going on?

Re: Vespa bravo refuses to idle

Andrew Snowberger /

Saw vespa-ciao.nl pics, the washer goes on top of the cam collar. Still no luck. Might resort to grinding/reducing the height of the cam collar, so hopefully the flywheel fits better on the shaft. Just don't have much time to work on this thing anymore, so I'm resorting to small goals.

Re: Vespa bravo refuses to idle

Andrew Snowberger /

Oh sh*t we are GO! I used a grinder to remove about 3mm and a file to level it

out. Now it sits lower, exposing more crankshaft for the flywheel to fit without wobbling. Ok! So... if you want the $30 DennyCycles budget needle bearing 12mm crankshaft, you need to ream about 1mm from the inside diameter of the cam collar and reduce the height of the collar by 3mm, and make the woodruff key 0.5mm thinner so you don't have to hammer it into the keyway. MopedDivision has vespa and kinetic cam collars real cheap, so I got a couple to damage as I figured out how this works. Found no obstructions under the flywheel to cause the catching as I try to pedal start, but while changing the base gasket I did notice how crude the cylinder ports are. Doubt thats going to hone out on its own.

IMG_20210321_140245333.jpg

Re: Vespa bravo refuses to idle

Andrew Snowberger /

Well, it's blatantly apparent I need to bore out my dellorto 12.10 to 13.13 or take the jump and find a 13.13 I can afford. I just got the bravo up to 28 with the 12.12 clone, but it just won't idle with that carb. It'll idle with the 12.10 with the engine cold and the choke on, but it won't idle on its own either, and only does 18-20 mph with that carb. So much for being able to make a clone into a daily...

Re: Vespa bravo refuses to idle

if you can make fu moped parts fit then you are in the correct moped dimensional spirit. but by this chart you should be able to get to 30 with the 12:10

https://myronsmopeds.com/wp-content/uploads/2015/06/Info-Vespa-7.jpg

is your exhaust plugged?

Re: Vespa bravo refuses to idle

two carbs won't idle, try a third?

as for the 30 mph top speed, check your gearing:

https://www.mopedarmy.com/wiki/Vespa_and_Kinetic_Transmissions

i'm getting low 40's on a grande with pipe, carb, and minor top end mods.

Re: Vespa bravo refuses to idle

The gearset installed in the rear wheel makes a huge difference too.

Re: Vespa bravo refuses to idle

Andrew Snowberger /

The exhaust isn't plugged, it's got less than 50 miles on it. But it does not fit well on the exhaust outlet, there are two small spots where the exhaust gasses spit upwards on the engine, I posted a pic of the exhaust in this thread. It's been suggested I need a DR kit. First bravo I owned almost 20 years ago had just a 13.13 and a sito plus exhaust, no engine work done, and a stock but modified variator, and that thing hit 45, according to a cop that pulled me over. After the ride yesterday I'm inclined to blame the variator attached to the transmission. It hardly changed ratio at all.

Re: Vespa bravo refuses to idle

Andrew Snowberger /

Ok ive got a proma in my treats cart and decide to once over the bike to see what else to get in this order. Only now did I notice the transmission fill bolt being loose and I took it off and tilted the bike and got a bunch of shiny liquid metal coming out of the fill hole. I think this changes my priorities from exhaust to first rebuilding the transmission and rear variator... Ugh

Re: Vespa bravo refuses to idle

Andrew Snowberger /

Alrighty then. Cleaned out the transmission and rear vari-clutch thing. Fixed the exhausts bends, cleaned and installed the real dellorto 12.10 I have with a 50 jet. Its running worse than before. No idle, wont start with the choke on. Leaks a crazy amount of liquid black stuff from the cylinder area. I'm pulling the motor today because the cooling fan seems to be spreading the leak, I cant figure out where its coming from.

Re: Vespa bravo refuses to idle

If its coming from the fan area its most likely your crank seal spewing gas out. Looks like you changed the seal out but literally theres no where else it could be coming from.

Re: Vespa bravo refuses to idle

Andrew Snowberger /

Can stuff come out of the crank seal? I thought it would be considered a vacuum leak. So ive got the motor in hand and the leak appears to be from the crankcase and base gasket. I had crappy quality paper gaskets to work with. Also I notice almost a mm of difference in height between the case halves where they meet the cylinder. The area under the flywheel is clean, so is the cylinder head. I'm wondering if the problem is the cheap cylinder kit from denny cycles. It needed lots of filing and knocking out of casting material out of the box, ive read about needing to plane a cylinder level

Re: Vespa bravo refuses to idle

Probably not the kit......Probably cheep gaskets. I always have to cut Vespa case gaskets and base gaskets by hand. They almost never line up correctly. If it is leaking at the base, I bet the gasket is not lined up with the kit.

Re: Vespa bravo refuses to idle

Andrew Snowberger /

What do you use to make your gaskets? Not beer cans and brown paper bags..? I'm willing to give that a shot. Am I supposed to be using sealant on the gaskets too?

Re: Vespa bravo refuses to idle

Gasket paper from an auto part store. Get a roll. Just soak it in oil before install.

Re: Vespa bravo refuses to idle

Andrew Snowberger /

Oil soak it? Ok. These gaskets are pretty thin. My local parts store might have some. Any particular thickness work best?

Re: Vespa bravo refuses to idle

Andrew Snowberger /

Hey! I just found gasket material at treats, does it really matter what thickness I use for base and case gaskets?

Re: Vespa bravo refuses to idle

The base does, as it'll space the cyl up and down. Messing up port timing. Just don't go too thick, you can always double them up if the Piston hits the head.

I've never used gasket material. Always cardboard. Soaked in oil. Kinda partial to cinnamon toast crunch myself.

Re: Vespa bravo refuses to idle

Andrew Snowberger /

Wtf I can get away with cereal boxes for gaskets? This changes everything!

Ok so as long as im taking the motor apart, does anyone know what numbers to look for if I use my multimeter on the lighting and ignition internal coils? Does that apply here..? I did notice that my coils were screwed down as far away from the flywheel as possible. I was able to push them a mm or so closer to the flywheel without making contact. I'll remember that when I put it back together.

Re: Vespa bravo refuses to idle

Ive had good luck with the treats paper case gasket, the brownish one. The base your gonna cut yourself id get the roll from napa, its about as thick as your finger nail. As for the mating surfaces mill them on a flat surface with sand paper.

Re: Vespa bravo refuses to idle

Andrew Snowberger /

Taking it apart and noticed a big difference in where the rings sit and the port sizing. Is this piston dead? I used a tank sealing kit hopefully no more scuffed piston. Piston on left is original, piston on right is denny cycle cheapie

0410211955.jpg

Re: Vespa bravo refuses to idle

Lets grow up, you start.

Re: Vespa bravo refuses to idle

Andrew Snowberger /

If one were to unbolt the case halves and they pop apart on their own, did I not set the bearings deep enough on the crankshaft, or was my case gasket too thin? Heres a shot of my drilled out intake and filed patch! Sloppy job. D'oh

0410212042.jpg

Re: Vespa bravo refuses to idle

Andrew Snowberger /

Its done. It idles and rips. Switched back to stock internals and top end, used kinetic gaskets for case and base, decked the cases, soldered in new blue wire for lighting coil since the original had just two strands left. Put the tecno speedy stock and said fuck it and put the clone carb in too. Fired up second kick.

Differences: the kinetic gaskets are composite and seal nicely. That and decking the cases made for no more leaks. The denny cycle cheap crankshaft and cylinder kit might work if I were to trim the top ring and get a piston that actually had a locating pin. The cheap crankshaft had 4mm less intake duration and not kidding it had black enamel paint on the rotary disc to make up for it being made too small to actually make a seal against the intake patch.

Now what. I got a dellorto 12.12 which I'm trying to doctor up its emulsion tube since it had just one big hole. Soldered shut the hole and am about to drill new holes. Then I can put the possibly pointless circuit exhaust on there and upset. Sorry, if I had read more here first this crap would have been only five posts long.

Re: Vespa bravo refuses to idle

That part...

Glad it is running.

Re: Vespa bravo refuses to idle

Andrew Snowberger /

Upjet. Not upset. But not really happy either way.

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