Modern Vespa

Back in May, my 2002 PX200E came to a stop and hasn't started up since.

Riding home, it cut out - it wasn't a seize, it just felt like it ran out of gas, despite its mostly full tank. I pulled over and tried to kick it several times; nothing happened. Then, it froze. Totally locked up. Oh no! I threw it in the back of a truck, and let it sit.

A few days later, the kickstart was unfrozen. Still didn't start. Froze up again. Unfroze, etc. I thought a broken piston ring might be jamming it, but upon examination things looked fine and there was no deep scoring.

The questionable gas flow led me to pull the line and drain it. The gas came out in spurts. I cleaned the tank and the line and fuel seemed to flow more smoothly. Still wouldn't start though and the kick still locked up.

Tonight, my friend pointed out that when he tried to kick it, it was slipping into gear. I hadn't noticed this before. I think I WOULD have noticed this before, but maybe not. It never gave me problems when it was running. His thoughts were a worn cruciform.

But... the series of events seems odd. I think it's likely the cruciform NOW, but am curious as to why it just cut out initially. Unrelated problems? So, what do you think is going on? I would love to hear any thoughts, suggestions, experiments, experiences, or comforting words.

Thanks, guys!

i don't know about the lock up on motor but the "just plain cut out" thing is exactly what happened to a buddy with a px200 crate motor.

it was his stator

wire shorted or something

i would give that a serious looky loo

Oh, so maybe similar to what happened with this ET4? Hmm, worth a look, definitely.

It sounds like your bike might have several things which need attention, so it might be hard for the Internet to help you unless you can isolate the issues and provide good detail... for example, what exactly do you mean by a frozen kickstart? Does the flywheel also "freeze" when this happens? Etc...

In general, take care of the physical problem (kickstart), then move on to fuel, compression, and spark (electrical).

Maybe you already have started with the simple things but didn't mention it... for example, if you're slipping into gear check your cable adjustment before suspecting a worn cruciform.

I also find it helpful to work from the outside in, if that makes sense... so you don't find yourself replacing your stator plate when there's just a short in your kill switch, or replacing your kickstart quadrant when there's just a problem with the lever splines.

I'm not saying there aren't some really cool and crazy things wrong with your bike, but nothing stands out at the moment as an obvious solution, and it always helps to plan your attack and eliminate the easy stuff.

+1
If I had to guess flywheel side woodruff key was worn or your starter sector/gear... but that's my guess

I,m going for a too long fuel pipe

yeah, i mean ... the question is ultimately "is the TOP END locking up" when you try to kickstart it.

The kickstart lever turns the primary drive, which turns the clutch and attached top-end to get it going. If something is impeding those things from turning, you've got a serious problem. I was thinking a stuck ring. Maybe you've broken a piston ring, which you won't know until you actually pull off the jug. Likely, you won't see scoring on the inside of the cylinder. It might be popping in and out of it's ring groove, which is what's making it happen periodically

The cruciform thing really shouldn't matter until it comes time for you to change gears. No matter how worn your cruciform is, if your bike is in neutral, your cruciform is in between gears... and shouldn't be interacting with them. If your SELECTOR BOX was bad ( particularly the arm that moves the cruciform back and forth had a lot of play in it )... then you might experience the cruciform moving in between gears when it shouldn't be... BUT ... really, you'd know if you went to kickstart it and all the sudden your bike was in first gear, because it would try to push itself off the centerstand with your kick.

No...it's something weirder. I'd split the cases and find out.

yep,sorry bell

the stator thing will have to wait

you must get motor in a turning condition first

i jumped to fast to a recent recent issue with a bike

I've looked at her bike in person (was one of the friends who've given her advice) but havent taken anything apart. Here's some of the details:

The bike sat for most of the winter, covered, then started up in April with a new plug. then sat for another month or so. Mid-May is when she had this problem, on a short (less than 2 mile) city ride, within days of starting to ride it again.

Another friend and she had taken the top end off and examined it, they said there was some carbon, but no scoring or pitting, and the rings seemed ok. Put the top end back on.

Last night, it WAS jumping into gear and off the center stand when we were trying to kick it. Gear cables were nice and snug, but we could change gears w/ engine off from 1st-N-2nd easily without pulling in the clutch lever (which is definitely not too tight). I spun the flywheel with my hand, and it turns over without restriction, aside from the compression effects of the top end. It'll kick normally the first few times before jumping into gear, and lights will flicker as the flywheel turns. Even when I was just depressing the kick lever by hand, it jumped into gear by the third depression.

My first thought was cruciform, or part of one of the gears chipped where the cruciform engages. A couple friends, both of whom have ridden and worked on scooters longer than I, thought the same. Another thought the clutch may have dried out from sitting too long with no gear oil change/fill-up in a long time.

My thoughts now are pull the clutch and rebuild it w/ new corks, then split the cases if that doesn't solve the problem.

ok... that's a good description, and i bet i know what it is.

1) Your selector box arm has got too much play in it

2) Remember that the P-series uses a 2-piece plunger, that's held together with a weird lock washer that you fold over to lock it in place. If someone didn't use that lock washer on the bike, then the two halves of the plunger might be coming unscrewed, and that extra space is allowing the cruciform to slip into gears when then the selector box appears fine and tight from the outside

3) the cruciform is coming unscrewed from the plunger... but i REALLY doubt that.

4) OR your gearstack is seriously lacking a shim, and the gears are just floating all over the place on the rear axle. You'd have to be off by a good couple MM before this happened, though... meaning someone reassembled the gearstack and forgot the shim entirely.

My money is on one of those things.

Thanks, Eric. We'll definitely closely examine the selector box assembly and see what we find.

You know what i mean, right? Pull it off and make sure that the arm on the inside doesn't float around while the batwing remains stationary. There should be no movement of the arm without movement of the batwing... etc.

when you "threw it in the back of a truck", did you happen to back it out or off the truck while in gear?

I haven't looked at any gear selector box too closely, haven't had the need before now, but looking at the diagram I have it looks easier to fix than splitting the cases (which I do have experience with), but I think I know what you mean, Eric.

Stefan, I honestly don't know what she did. She usually treats the bike well, but I wasn't there that night. My guess is whoever she had help her had experience with bikes and would've kept it in neutral, but I dunno for sure.

You can inspect the selector box in about 2 minutes. You just have to pop off the two bolts that hold it to the side of the case. You don't even have to unhook the cables! ( in fact, i recommend NOT unhooking the cables )

Some times people have a problem pulling the selector box off, and it requires a little working it from side to side to get it off. Kinda spin the little plunger with your fingers as you pull it out, and the cruciform should find it's way through all 4 gears.

Yeah, I've taken it off to drop the engine before, just never paid too much attention to anything but the pulley/cable assy. up top since it was working fine.

So, it's been a while on this thread, I know.

Anyway, today we moved the bike inside to her basement, and I finally took off the gear selector. Everything was solid, it functioned normally. The plunger was also screwed in all the way, with less than 1mm play.

Anyway, buttoned it back up, kicked it over, it actually started up for about 3-4 revs, then cut out. The bike was still in neutral, I was able to roll it around easily.

Tried kicking it again, every 3-4 kicks, the lever would lock up. When I tried turning the flywheel directly, it would be locked from turning forward, but if I turned it backward a bit, I could then bring it forward past the point where it locked up. However, even with the clutch pulled in, the kick lever would still lock up, which leads me to believe there's something jamming in the gear box.

She's pretty much accepted that we're going to have to split the cases, and at least there's a warm, dry place to do it, but can anyone suggest anything in particular to look for? I plan to inspect the whole kickstart assembly and Christmas tree, and take the clutch apart and at least soak the corks if not rebuild it. (Are there any tricks to a Cosa clutch that are different from a standard largeframe clutch?) And check the independent gears as well. Plus all the regular rebuild stuff - cruciform, seals, etc.

Thanks.