Modern Vespa

I have a 1967 150 super thats been modified with a 1980 p200e engine. I recently cleaned the carb, replaced an old gas line, replaced a pinched oil line, and all the cables are running nice into the carb (choke, replaced)(and the throttle with needle is nice. So it took a few minutes to get the gas and oil into the engine, but i got her running. So excitingly ofcourse, I took her for a ride right away. It took some throttling,but she was back and running better than before! No issues getting into 3rd gear (which was a problem a few months back) So i parked her for a while, ran the engine on close to empty some gas in there. And now im just having the most difficulty starting this thing up. im hoping someone with more knowledge can help me out please! first engine im working on

Thanks!

Uh, the obvious... put more gas into it?

Seriously, maybe try to put the fuel tap to "reserve"

i replaced the fuel line myself. you dont think I put gas in? maybe some real help and not a hater. she runs good but def difficulties starting up. my previous vespa had the same engine year and size, was much easier(and reliable) to start up.

Not a hater at all, just reading that you ran it almost out of gas.....

I know my P200 starts much more easily with a full tank as opposed to an almost empty one.

You might check the routing of your fuel line and make sure it's not too long. Have you removed the fuel line at the carb to determine you're getting appropriate fuel flow?

Did you re-adjust the mixture screw after the rebuild?

i did. same length as the old one. and fuel is coming through.

yea i did adjust it when i rebuilt the carb. was advised to unscrew after fully in 1.5 turns. i got her running after all my work done. but for some reason the start is just really hit or miss.

yea my bad. i wrote that out wrong. i ran it with the gas lever on close before it turned off.

...and just how long was that old fuel line?

its like 2 ft long. just long enough to pop the tank up a bit but not fully out without disconnecting gas

Pull the plug, post a pic and let us know what jets you have in there as well as what size carb.

Another: how did you set up the timing?

Are you parking it on any hills? Did you replace the float and needle? It could be accidentally flooding the scooter while parked.

i will soon, bit busy today. the carb is a dellorto 2020. just finished a clean on the whole carb too. should i open and check the jets?

flat park. only indoors. cleaned the carb out last week with all new pieces!

i did not set up the timing. something that needs to be done after my upgrades?

Weird thing is the other day when i got it running. Took a spin around the neighborhood. ran great. its something specifically with the start that is driving me crazy! just wanna ride lol

is the choke working? Is the plug wet? You could easily check that and shoot some quick start to get it to fire. Check your air fuel mixture and when it running and warm set the idle screw.

so choke is working. i replaced the choke myself. doesnt stay fully out(cause its new i think) but stays almost fully out. or i hold it fully out with my left hand when i kick. but soemtimes i do see some gas on the spark plug when i pull it out after trying to kick start it.

This, and check spark when plug is out. If no spark it could be electric. Have a new plug handy in case old is buggered. Try the new one anyway.

If plug really wet, turn off fuel, wind up throttle and kick it over 20+ times with plug out to clear gas before putting plug in and trying again. Then work out why its flooding! New needle after your clean maybe?

yea so checked the plug. good spark. can even see the headlights pick up good light when im kicking it too. lotsa new plugs handy. so i just got her to start. ran her around the neighborhood, got up to 3rd gear for a bit to warm the engine. then i parked her. close the fuel line and ran the engine til it died. i waited like 15 min. cant get the thing to start with like 15+ kicks even

Maybe stop doing that? I never do unless putting the bike away for a while. If your float valve is good shouldn't be a problem. and if it is bad, you will know soon enough and you should get it working properly so you DON't have to turn the gas off EVERY time.

Now your carb is dry and you need to get gas all the way to the cylinder before anything can happen. I like to lean my bike as far to the right as I can and something touches the ground for about 5 seconds. This causes the float bowl to overflow into the venturi 'priming' the motor and it usually fires right up. But if it is flooded, this is the wrong way to go. If you are unsure, pull the plug to see wet or dry and now you know what direction to take.

Your choke has a little spring clip to hold position, if not on right your choke will return to off all by itself as you have discovered. If you wanna pull the tank and take a picture, you can get plenty of advice on how to fix that if needed.

Anyone got a pic of that spring clip +/- installed? Couldn't find a good pic in the manuals (but will have another look later today)

I've just routed the choke cable and cheated the install with a zip tie. Means my choke springs back, which after reading this, answers my question of if that is intended. Probably have that clip lying around.

From scooterhelp.com

Thanks! Forgot how useful scooterhelp can be.