Modern Vespa

This really helped me find my two air leaks!https://www.youtube.com/watch?v=uVM-mgcqAck

Also I sprayed carb cleaner in all those spots and when the revs went crazy I knew that was a spot. Mine were on the cylinder base and flyside seal

You should be doing the leak test without the flywheel / stator, clutch. Another part that fails over time is the auto lube shaft that's pressed in the cases…

How do you seal up that one?

Since we ditched the auto lube forever on that one, I used Loctite 603 and pressed it further in…

Just for fun, I"m going to mount a spare P200 cylinder and head that I have to see if there is any leakage there... couldn't hurt.

Yesterday I reassembled the front hub and now have working speedometer and brake assembly. I was surprised to find that this assembly still uses a Dent Nut. That seems like very simplistic mechanics and i would have thought Vespa would have used some sort of lock washer. Anybody know why they still use a Dent Nut?

Do the two rivets on the steering lock have to be drilled out or is there a way to pry them out?

you can pry the cover up and the rivets will back out. Often they can be reused as well.

Couldn't pry the cover loose. I needed brute strength and ignorance (and a Dremel) to get it off. Drilling out the cylinder comes next

My 1981 P150X have same. You don't have keys?

No, no keys so I bought Scooter Mercato's set of new locks for the seat, glove box and steering column. They are all keyed alike. I've already drilled out and replaced the glove box lock and replaced the seat lock and drilling out the steering lock is next.

My engine is out still trying to find that pesky air leak... but without success so far. In the meantime, I replaced the steering column lock which turned out to be a tougher project that I expected. I learned that it is much easier if you use sharp drill bits... at least they were sharp when I started.

About the air leak is your clutch in the bike when you're pressure testing? If not your leak may be the clutch seal. If yes then never me mind!

The engine leaks with the clutch in or out… it is currently out. When I first discovered that I had a leak I went ahead and replaced all three seals but it still leaks and that is why this is so frustrating. I can't find the leak and neither can the guy I took it too. Damn![/url]

Have you tried the little spindle the autolube pump sits on? It's pressed through the case in the crankshaft area. See if you can wiggle that.

After that, I'd look at a leak at one of the studs.

No, I haven't tried that… but I will

If all else fails a smoke machine makes it so easy to find your leaks. If you can't borrow one, just check here : https://modernvespa.com/forum/post2617717#2617717

Gotcha you bastard!!! Or at least I do for now.

I ran a couple more smoke tests which showed that I still had a leak, but didn't disclose the location. Borrowed a vacuum tester which also showed that I still had a leak but, of course, also couldn't identify the location.

I finally said Screw It and put the engine back in the frame this morning. I started it up and again, the engine screamed so I shut it down. I started it a couple more times with the same result but on the third attempt, after continuously blipping the throttle, I finally got the engine to slow down and begin responding the throttle. I let it rest for a couple of hours and started it again, and again, it is running properly.

I don't know why, I don't know how, but I really don't give a shit.

Yes, I know I haven't fixed the problem and it will probably come back to haunt me, but for now, I'm not going to sweat it. As my friend SJanuary, said, "Don't worry about it... if there is an air leak, it will find you."

Hooked up the clutch and updated the rear brake cable this morning. Tomorrow it's the gear shifter box and the engine shroud and then I should be able to take Red Rover for a ride.

Yes I know I'm slow but with 21 days of 100+ degree weather in Fresno, I don't have much time to work in the garage before it turns into an oven.

You can always redo the pressure test with the engine in the bike. I have found the soapy water test never fails to point out the source of the leak. As you said, it will find you and you will have to fix it eventually. I totally understand the need to at least ride and enjoy it a little when the motivation for endless dicking around starts to wear thin.

Gotcha ya bastard!

I took Red Rover out on the road yesterday (actually, just the street in front of my house) and rode it up and down the block a couple of times. It ran "ok". It still needs a lot of fine tuning but at least it didn't scream but I kept my thumb on the kill switch though just in case the air leak returned unexpectedly.

There is still a LOT of work yet to be done before it is truly road-worthy, but at least I'm making progress.

Great job! Congrats mate!

I have to replace the Oil Tank Ring nut, Part 5, but I don't know how to get it onto the gas tank... just force it? (That doesn't usually end well for me.)

Looks like it threads onto the tank

Never mind.

I found a Robot video that deals with gas and oil tanks. It shows that the ring nut slides over a tube that extends into the tank and does not have to be forced over a lip. Good to learn. I looked all over for a video like this but couldn't find what I needed. (Not for the first time)

Can anyone recommend a good liquid paint remover for factory paint? I need to remove a lot of paint from the cowls and I don't really want to sand it off and risk scuffing the bare metal underneath.

why remove it at all? sand out the damages, fill the low spots with glazing putty, even up the surface, scuff it again and move on. factory paint is a great base.

Yeah, sanding would work but I'm not very good at it. It always looks like shit so I thought I might be better off just removing it all which is why I was asking about paint remover. I'm not familiar with glazing putty... is that similar to bondo? (I suck at using bondo too). Is it something you get at an auto parts store and does it just fill in paint chips?

sanding is about zen patience. and working from coarser to finer.

your bare metal surface will need filler and sanding after primer, it's just how it is. if you don't sand it smooth between primer and paint you will regret it.

Yeah I know, "I want patience and I want it now!"... that's my trouble.

Ok, I'll try sanding it out. Is "filler" the same as "glazing putty" and is that the same as Bondo? Sorry, but this is all new to me so I have to ask.

Can I use regular Bondo to fill in paint chips or is there something special?

for chips, use glazing putty

have a read here:
paint how to thread (Page 4)

and if you want, you can look at the index on my topic (first post) and find my adventures painting cowls, fenders, etc., using rattle cans to decent results

https://modernvespa.com/forum/post2481363#2481363

Thanks SDJohn. Lots of good information. I think that the glazing putty will solve a lot of problems for me

it all gets easier when you realize that if you screw up, you can just sand it and try again. guide coats can show you your low/high spots and you can work from there. my best painted piece had paint and clear on it that i sanded back into and tried again because of runs, but it made a kick ass base for the next go around.

patience patience patience is the key, along with being able to know when to stop because nobody but you will notice if you improve it further.

These are some sage words of wisdom...

Absolutely! I hate to think about how many things I've screwed up because I thought "Well, if I just do a little bit more..."

Well, this has been a learning experience. I've learned that I don't know how to use a hammer and dolly, I've learned that I don't know how to use Bondo and I've learned that I don't know how to paint.

The previous owner apparently put Red Rover down on the fly side as there was considerable damage to the fly side leg shield which was bent back and also to the cowl which was dented and scraped.

I started with the cowl and pounded out the big dent and most of the smaller dents but not all of them. I figured that with primer and paint, they wouldn't show... Wrong!

Clearly, I need to learn how to do things properly, beginning with Bondo. I was having trouble with it setting up so quickly that I couldn't work with it. It was later that I learned that Bondo sets up with heat and since I was working in my garage in 95 degrees. I didn't have a chance. I know that people talk about a "10 foot paint job",... mine only looks good at 20 feet.

I'm working on the clutch side cowl now and applying the lesson's I've learned. Fortunately, there aren't any dents so I won't have to mess with Bondo so I'll work on improving my painting skills.

I'll redo the fly side cowl later on... there is still a lot of other work that needs to be done on Red Rover.

Thanks to SDJohn for all the advice.

Don't be so hard on yourself my friend. You'll get the hang of it the more you practice.

And you'll have a much greater appreciation for those beautifully restored machines that don't even use Bondo, but a little glazing putty.....

it's a perfect base to try again

if you can see it, never assume it will disappear with paint. it will only magnify.

it takes practice, nobody paints the mona lisa on the first try.

btw those dimples and metal imperfections are perfect candidates for a nice thin layer of filler, I can't remember the one that socalguy turned me on to but it works fantastic for thin stuff. it's in my thread.