Modern Vespa

OK... after reading that whole thread....

I honestly think it was something stupid, like it was flooded or something.

Did you try bump-starting it? I never read that you did, and it's something i ALWAYS do. If i can't get a bike running after 5 minutes of bumpstarting ( and the corresponding cardiac arrest i give myself ) then something is SERIOUSLY wrong with it ( like, my timing is way the hell off ).

And, i'm in agreement with Gene that the GS original coils, though some people hate them because eventually the housing cracks and lets water in and then they get unreliable, i think they are super reliable... and, well, they're original so i'm more likely to want to keep it on my bike. I've got the repop and it's certainly nicer than the repop.

So... i'm not inclined to read into this too far. If it happens again with the same symptoms, i'd be concerned... but i think i'd just let this one slide... and try bumpstarting the next time it happens.

I honestly think you just flooded it. Sometimes i'll take out the spark plug and hold a lighter to the hole and kick the bike ( don't sit too close, it's like a momentary flame thrower ) ....or bumpstarting will clear out those floods.

Thanks for the lesson, it's good to know. So does that mean the only time that the key would shear is if the nut is coming loose? Is it almost a form of protective measure so that things would stop running before the flywheel actually flew off?

Nevertheless, a good fitting woodruff key, in my experience, is required for accurate timing checks. Otherwise slop/play can mean it seems to position well when racheted down (but not torqued down to 40 lbs/ft) and one performs a timing check, but then positioning can vary slightly as you fully torque it down and what seemed like an accurate setting no longer is because of the slight flywheel play relative to the crank. It happened to my with my Super, and was frustrating until the key was fixed in place with the JB Weld (because of slop on the crank cut). I suppose this could have been checked with a fully torqued flywheel each time, and if it was good then just having left it, but it would still be hard to get accurate placement.

In any event, I'd replace a worn woodruff key.

Yes.

The key should not be able to shear if parts in good condition have been properly bolted together.

As far as why it's there - in the case of the flywheel, it's easy to say that it's there so that the timing is properly indexed.

In the case of the clutch (and getting to the heart of things), I believe it is there to prevent movement of the shaft during tightening, as the connection between the shaft and the clutch should consist of force pressing straight down, and rotating it in the process would allow for some slop that could increase with use, ultimately leading to failure (someone smarter than me tell me if I'm wrong). I'm lucky - the 2-piece flywheel on my 160 allows me access to the timing bolts with the timing cam fully torqued down.

- Eric

about your flywheel key, if you lap the flywheel to crankshaft with fine lapping compound & have a dull gray finish on both parts after removing all oil residue you can actually run without a key. we used to do this in kart racing days & could move the timing by not having key never had trouble with it moving, just clean real good after lapping , no oil on surfaces. this will work well. valve grinding compound, forgot to specify.

If you are concerned about the oil residue, you can also use water-soluble valve grinding compound.

Have you found any difference in results between a "spinning" motion (constant rotation) and an "oscillating" movement (like you were lapping valves) when lapping a shaft?

I like this idea, and may try it on my flywheel (with the key) one day, just to be sure the surfaces mate up as well as possible, after 45 years of abuse.

Thanks.

- Eric

i have not tried the water soluble compound i used oil base cleaned with spray carb cleaner, if lapped well & cleaned you will like results.

mdchanic, i always used the oscilating motion not rotary, just like i do valves worked real well, rotary motion may work as well , don't know.

Thanks.

FWIW, I've always used water soluble compound - don't think there's a difference in effect, but if I'm lapping valves, that pretty much means I'll be washing the head in detergent and water, and water soluble compound is easy to wash away.

- Eric

Interesting comment. So why did you do this, just to remove a step and not have to touch the stator, but only slightly rotate the flywheel instead to affect timing? Did it save a lot of time/effort? For me most of the work is in using a breaker bar or otherwise to release the flywheel nut, and to make the flywheel spin relative to the crankshaft I'd have to use the flyhweel puller anyway... That, and torquing it back on, of course.

The idea that having to make *really* sure that the surfaces are clean and using a grinding compound if you're running without a key does, at least in some way, suggest that the key IS doing something in terms of force for those of us that don't have such a pristine mating between shaft and flywheel... (and I wonder if I'll run into some sorn of porn filter for using shaft and mating in the same sentence... ).

phaetn, i do this mainly for a very good taper fit between crank & flywheel to prevent key from shearing if you put one. if done right & tightened correctly your key problems are over, if not using key you can move timing mainly on electronic ignition. it's well worth time to lap.

Anywho

1) Does anyone know of any specific torque wrench settings for the case bolts. I don't want to undertighten or overtighten, for obvious reasons.

2) Also does anyone have advice for fitting a fresh piston and rings into the barrel? I haven't TRIED on the P yet (tomorrow night, baby), but I recall keeping the rings compressed while inserting the piston was a serious pain in the ass on my old moped back in the day.

Thanks!

I just saw the case bolt settings the other day...

18ft-lbs maybe?

Crap I'm guessing, but I was surprised b/c it was far less than I figured it would be.

Torque Wrench Settings

Standard Settings
BOLTS
5mm bolt or nut: 0.45-0.6 kgf m (3.5-4.5 lbf ft)
6mm bolt or nut: 0.8-1.2 kgf m (6-9 lbf ft)
8mm bolt or nut: 1.8-2.5 kgf m (13-18 lbf ft)
10mm bolt or nut: 3.0-4.0 kgf m (22-29 lbf ft)
12mm bolt or nut: 5.0-6.0 kgf m (36-43 lbf ft)

SCREWS
5mm screw: 0.35-0.5 kgf m (2.5-3.6 lbf ft)
6mm screw: 0.7-1.1 kgf m (5-8 lbf ft)

FLANGE BOLTS
6mm flange bolt: 1.0-1.4 kgf m (7-10 lbf ft)
8mm flange bolt: 2.4-3.0 kgf m (17-22 lbf ft)
10mm flange bolt: 3.0-4.0 kgf m (22-29 lbf ft)

Engine & Tranny Settings
Stator Screws: 0.3-0.4 kgf m (2.17-2.89 lbf ft)
Kickstart Lever Nut: 2.3-2.6 kgf m (16.64-18.81 lbf ft)
Coil Pickup mounting screws: 0.2-0.25 kgf m (1.45-1.81 lbf ft)
Clutch Center Nut: 4.0-4.5 kgf m (28.93-32.55 lbf ft)
Input Shat Nut: 3.5-3.5 kgf m (21.70-25.32 lbf ft)
Rotor Nut: 6.0-6.5 kgf m (43.40-47.01 lbf ft)
Carb Sleeve Nuts: 1.6-2.0 kgf m (11.57-14.47 lbf ft)
Clutch Cover Bolts: 0.6-0.8 kgf m (4.34-5.79 lbf ft)
Cylinder Head Nuts: 1.7-2.2 kgf m (12.30-15.91 lbf ft)
Exhaust Pipe Stub: 7.5-8.0 kgf m (54.25-57.86 lbf ft)

Frame & Suspension Settings
Suspension unit mounting plate nuts: 2.0-2.7 kgf m (14.5-19.5 lbf ft)
Suspension unit to mounting plate nut: 3.0-4.0 kgf m (21.7-28.9 lbf ft)
Suspension unit lower mounting nuts: 2.0-2.7 kgf m (14.5-19.5 lbf ft)
Steering head adjuster (preload): 0.6-0.7 kgf m (4.34-5.06 lbf ft)
Steering head locknut: 5.0-6.0 kgf m (36.2-43.4 lbf ft)
Handlebar pinch bolt: 3.0-4.4 kgf m (21.7-28.9 lbf ft)
Rear suspension unit lower mounting bolt: 1.3-2.3 kgf m (9.4-16.6 lbf ft)
Engine unit pivot unit: 6.1-7.5 kgf m (44.1-54.3 lbf ft)
Front wheel hub nut: 7.0-10.0 kgf m (43.4-72.3 lbf ft)
Rear wheel hub nut: 7.5-9.0 kgf m (54.3-65.1 lbf ft)
Wheel mounting nuts: 2.0-2.7 kgf m (14.5-19.5 lbf ft)

Thanks Eric,
I did see that list before, but since "case bolts" aren't on there I wasn't sure if I should just treat them as "standard settings" bolts or what.

Yes. They get treated as standard nuts. Whatever the diameter ( i can't remember what they are )

So,
The outer case bolts will cinch up nice and tight. But these two in the center... there is no way in hell I can get 20 lbs let alone ~30 on them. I swear I was as gentle as a lamb, so I didn't do it, but it seems someone at some point stripped these guys out over the years. They don't tighten very tight at all before they slip.

Does this mean my bleeping cases are trash?

Please god say no.

Keep the faith man. There has to be a solution.

Have you tried a new nut to see if it maybe gets a better bite on the bolt?

Also, I've never done it (so please get more expert advice than this), but you might be able to use a die nut to rethread them? The scary thing about that though... if you aren't bang-on straight you'll cross-thread the bolts and then be in a bigger pickle.

I'll be watching this to see what the more experienced suggest.

I am no god, but i say NO

Mate, i received your PM. You will be alright, honest.

Okay, Do the two nuts spin out against the case or do the studs spin?

Either way, it can be repaired with minimal stress and effort. I will check tomorrow but i believe if you have stripped the case then you will need a Helicoil kit 8mm x 1.25 for the 11mm-1.25 (i can tell you for certain in the morning). It's late and i want to make sure i give you the correct size.

I have repaired too many for mates over the years and i can tell you never use a torque wrench on these studs. Though some might question this, i always use a 1/4'' on case work. I repaired one that my mate pete stripped on his P2, what a stress bucket he was.

When buying a use scooter you just never know mate, This might have been done by the previous owner? Nae bother, again it's an easy fix.

You by the way, are doing a great job. Hang in there.

Feel free to give me a call tomorrow if you need any help.

207 691 0880

Cheers

What Jim said.

If the studs are stripped, just back 'em out with vise-grips and replace (generic item).

If the case is stripped, just Helicoil it.
It's surprisingly fast and easy, and stronger afterward than original.

No biggie.

- Eric

Hm hm, ok, this sounds better. A good night's sleep and some sage advice. So use a torque wrench on the outer case bolts (to about 30 lbs?) but not on the crank-case area studs.

Crank-area studs just tighten with a ratchet until the lock-washer is compressed, but no more?

Regarding the helicoil... I looked it up but had never heard of such a thing before now. Do you stick it on the end of the stud and then stick the stud down in there and screw it in? Or how does that work? Also, can I use the helicoils without splitting the cases back apart? Or do I need to go back through all that again?

Thanks guys!

man... 30 ft/lbs sounds crazy tight. I mean, the flywheel nut is only supposed to be like 45 ftlbs, right?

I think they should be around 15 ftlbs TOPS.

the hcoil set can be bought at a auto parts store

take in the stud and nut and they will size it

30 IS high

head nuts are aroud 11

go slow xany

Ok, I was just going by the list you posted above... Eric said to use the standard settings:
10mm bolt or nut: 3.0-4.0 kgf m (22-29 lbf ft)
12mm bolt or nut: 5.0-6.0 kgf m (36-43 lbf ft)

It's an 11mm

It took me a while to wrench down my flyhweel nut to 45 ft/lbs.

on line yyou can find your owners manu

go to the torque settings page

around pg54 or 55

I know that's what the chart says... i'm wondering how that can be possible.

Maybe it means that if the threaded area of the bolt is 10mm wide, then 30ft/lbs?

I pulled that Torque setting list off of Vespa Maintenance ... and the other specs seem right, but those don't.

Maybe.
I mean, whatever, I'd much rather just go with the instinct you guys have on this. I've only taken this case apart and put it back together once now... I'm still a budding young grasshopper. If you think 30 is way too high and your suggested level of tightening gets the job done and won't strip anything then that's all I need!

The studs in the case are the same size as the cylinder head studs so even if you figure it that way 12lbs is more than enough. Even the haynes manual says 9.4-13.9lbs for the cylinder head.

True...for the lower compression bikes. I think the rally and P are both like ~13-17 ft/lbs, are they not?

i found this on smallframes.com

Install all the case bolts, washers and nuts. Evenly tourque them down. These nuts can strip threads and bolts can shear, so don't go mad. About 45lb/ft is correct. (Or as tight as you can do it with your socket set with firm arm pressure, not a bloody great long breaker bar!)

i am confused

Yeah, that's nutty. There's no way those case bolts should be that high!

I don't even do 45 ft lbs on my flywheel. I go as hard as i can turn it without a breaker bar, but i'd be impressed if that's much over 35 ft lbs.

Y'know, there's something to be said for "mechanics' feel," as described in Zen and the Art of Motorcycle Maintenance.

I torque head bolts (except on my GS, as I could find no numbers in the manual, and I figure any other numbers were pulled out of someone else's butt, so I might as well pull one out of my own), but I never use a torque wrench on anything else.

It needs to feel right, and if it does, it's tight enough.

The hard part is knowing when it feels "right."

But don't over-rely on that torque wrench.

- Eric

ps: for those who really want to try to get their torque settings right, try this calculator.

http://www.scooterhelp.com/manuals/VNX1T.VSX1T.service.manual/71.jpg


p125 and 200

So those match with Vespamaintenance's figures and my Haynes. 13-16 lbs for the head bolts

bottom line xany

you and i have to remember the mv help theory

if more than three trusted wrenchers say the same thing than chances are your in the right direction.

eric---30 is high---10 to 13 is about right
md mechanic----feels right-----probable around 12--def not 45
mattgyver----12 sounds about right


so, my common sence says 30 to 45 is wrong and around 12 is right, PERIOD.

More good advice Jimmy.
I'll look into the helicoils and get this beast on the road!
I estimate in two weeks I will be riding if my work schedule holds steady

Yes, to be clear, I concur.

12ish ft pounds sounds good.

- Eric

Most of those measurements are correct if the you are talking about the stud not the nut.

6mm stud=10mm nut
7mm stud=11mm nut
8mm stud=13mm nut

Certainly. The numbers on Metric and American fasteners refer to the nominal diameter of the shaft of the fastener before the threads are cut, NOT to the wrench size.

If you are talking Whitworth fasteners, however, it is the opposite.

Oh, and the 8mm fasteners on older Vespas are all 14mm.

- Eric