Modern Vespa

Need assistance with a 2007 LX150 that is causing me to tear what little hair I have left out.

I had a guy offer to buy my bike at the start of month. We arranged for him to come to my house later that month.

Two weeks ago I managed to track down all the gremlins affecting it after I had removed engine to change belt and variator ( Bad spark , blogged jets {twice}; spark plug wire pulling out of spark plug cap)

Got it all sorted , fired up first push of button. Only issue was to adjust the connection of throttle on carb as it was idling way too fast.

The guy came around this week to actually see bike. I went out that morning, popped in the battery which is kept in house and fully charged, and the bike would turn over, but not fire up. ( It was -15 that day)

He said he wants to buy the bike but I told him I wont sell it to him unless he actually sees it run like I promised.

Went out today and started troubleshooting. Battery was topped up, and I get a spark on testing plug (new) being grounded to engine case. (tested and wire and cap are tight)

But when I crank engine to check fuel, none comes out.

WTF????? Just shoot me now !

So I pop vacuum line off the manifold between carb and head, and blow into it to see if it has a leak. Strong resistance, so no leak.

NOTE : I did the EVAP removal several years ago and replaced all vacuum and gas lines then with quality ones.

If I suck on the vacuum line, gas flows from the fuel line, so petcock is fine.

I replaced the rubber manifold between carb and head as I had a spare. (
I had to reuse the gasket which had no tears or damage. )

It still wont create a vacuum and allow gas to flow?


Any ideas?


I considered the fact that I didn't have gasket sealant on it might have been the issue , but I ran it like that for years with no issue.

Another item. I pulled the rear hose off the carb and tried to start it with Quick Start Carb spray. It wouldn't start on it either? Do I have carb and manifold issues?

Thanks

Have to ask..kill switch?

Is it possible you've got the hoses connected incorrectly?

You've changed several things at once, so it confuses things a bit. Also, contradictory issues (like no fuel flow, but also no running on start fluid) complicate matters.

The hoses are on correctly.

After evap removal the gas goes straight to carb; and vacuum goes to the connection on rubber manifold between carb and head (with a tee to one other connection on engine).

The no start with fluid is throwing me as it takes fuel/vacuum out of equation so I am going to reset spark. I wasnt seeing constant blue spark but also a thin red spark, so maybe that wire/cap or even coil itself is issue. I believe I have a spare to test with.

It has been awhile since I worked on a LX or ET4, but I can only remember the vacuum line coming off the bottom of the petcock straight to the intake manifold as the T connection was eliminated after the Evap stuff was stripped out. If you can't get a some popping after spraying some starting fluid, I don't think it's getting spark. Pull the plug and check it, replace if necessary, then check for fuel delivery. Once you know it is getting fuel to the carb by pulling the fuel line at the carb and applying vacuum, then move on to a possible stuck float. Tapping the side of the carb works some time and saves you from pulling it. If this all checks out, you probably should check the valve clearances

I used my spare coil\wire\cap, and it fired up and ran 1st hit of the button.

I should have stopped when the spark wasn't always blue and worked on that first.

Thanks for all the suggestions

Awesome! (But then why was there no fuel flow?)

Did you end up selling it then?

I have an idea why it didn't appear to be flowing fuel.

All I can guess is that me sucking on the vacuum line opened it a lot so a lot of fuel flowed, so that when it tried normally it didn't seem to be flowing any.

One I had it running, we completed the sale.