Modern Vespa

Felt like getting back out into garage this week to split both my orange stella and old white p125 engines to rebuild them both at the same time.

Orange stella engine came apart easy. I figured it would be a bear as it wouldn't kick over, guessed the piston was frozen in cylinder. Turned out, the piston was in a million pieces and not seized, nor was the crankshaft seized. There was a lot of oil in the crankshaft area so my guess is there was an oil leak between gearbox and crank case, oil sucker.. and that caused a seize. The problem with kickstart not budging was a bent kickstart quadrant! My guess is the piston exploded and some fragment got stuck preventing the piston from moving and someone kept jumping on the kickstart lever trying to get it to budge. I know I contributed to that. Took 45 minutes of smacking away at it with a ball peen hammer and a punch to get the quadrant out. Possibly the kickstart hole has some damage from forcing the bent shaft out, but the surface isn't damaged, so im hoping new oil seals and new quadrant will prevent any serious oil leaks as long as that hole wasn't warped from the extraction.


P125 turned out to be the bear that is fighting me tooth and nail. Exhaust mounting bolt that goes through the swingarm is seized in the swingarm hole. I broke the bolt head off trying to unscrew it. Had to cut the exhaust mounting tabs off so I could get the exhaust off. More time trying to hammer that bolt out proved fruitless. Moved on to splitting cases and the rear hub castle nut is seized on the axle, plus the longest case securing bolt that goes through the thickest part of the case at the bottom is seized in its hole. Spent quite a bit of time with a blowtorch, punch and hammer trying to tap that out from behind. No budging.

I'm thinking I may have to find a machinist to drill these bolts out so I can get the engine split.


Orange stella. piston seen better days. Did a little damage to the crank web case surface.

it hangs to the left.

exhaust bolt seized in place.

smacking it from this end did nothing.

gave up on this... can probably get this one removed by re-installing a wheel and using some leverage.

this is the PIA that I'll probably have to find someone to drill out of the hole.

i spent a lot of time and heat smacking at this with no results.

Your case splitting challenges are normal for a bike ridden year round where they salt the roads. Wait'll you tackle a front fork that's suffered that indignity.

I had a similar issue with a stuck case bolt on my P200 motor. I wound up letting it soak under PB Blaster overnight. The next morning, I stuck my heat gun in a vise pointed at the offending area, then sprayed it with PB Blaster and beat on it with a hammer and punch every five or ten minutes until it eventually came out.

Time, heat, penetrating solvent, and judicious violence will eventually win the day.

Break out the gas ax to heat things up. A heat gun just can't compare. When reassembling, use plenty of anti-seize on the shaft of the bolt.

Last edited by whodatschrome on Thu Oct 28, 2021 4:41 pm; edited 1 time in total

MAP torch ... and never look back.

Lemme jump in here to help decipher the good advice.

What they mean is:
1. Use a long srcew driver or the like - to reach down inside the swing arm and chip out the cement that is holding it in place all the way inside the arm. Keep turning it over and dumping out the remnants and chipping some more. Spray what ever oily stuff you can in there and do it some more.

2. Get out a map gas torch and heat the f'ck out of the cases in the area where that long (now broken) bolt is. When you think its hot enough - make it hotter.

Use a punch (old drill bit or the like will do) and a dead blow hammer - and knock that thing out with some joy as it starts to move. if its broken off - cut the head at the other side so you can drive the straight end through (broken end will be bent).

Mine was permabonded in with Indonesian rusty mud from the 1963 monsoons (totally making that event up). But there is no way yours is worse. I was worried I'd brake the cases. Heat heat heat.

What CM2 said, but I'd use a claw hammer or small sledge. The shock force of the inelastic impact of metal on metal will pop it out much better than a deadblow.

You're not worried about breaking something here, you're worried about NOT breaking something (namely the bonding of the bolt to the cases).

Hahahah - Chandlerman just deciphered my deciphering.
Until just this moment - when I looked it up - I thought a dead blow hammer was in fact the mini sledge hammer I have.
Always thought that "dead blow" meant small sledge hammer that you can kill something with.

¯\_(ツ)_/¯

Takes a village.

LOL! I also speak Jive, Redneck, and some rusty German in addition to fairly fluent Charlieman

Yeah, a deadblow hammer looks like a sledge hammer, but it has a void that's filled with sand or lead/steel shot so it provides an extremely elastic impact. Lots of force, very little shock or kickback when you hit something with it. It's like a rubber mallet, only more so. I use mine if I need to do a little bit of persuading on engine cases and the like.

Had a P200 engine exactly like yours. Seized exhaust bolt and swingarm through stud. It was given to me for free. Scooter sat outside for years on a Greek island. Frame rotten to pieces. Had to drill them both, nothing I tried worked. Engine went on my Ratty black PX after a full rebuild and a bit of O-Tune...

ha! Holy hell safis! I'm right there with you on this engine. CM/CM22 heat did not help! I tried further today with heating the bolt red hot and the cases for about 25 min and hammering with punch and heavy hammer. Nothing would budge. I mushroomed the end of the swingarm bolt and could see the case was most likely starting to hairline fracture on the small side around that seized bolt so I stopped.

I ended up taking the dremel out, grinding the mushroomed tip of the bolt off to a flat surface again, then center punch and drilling it out from the nut/small side gradually up from tiny drill bit to almost same size as bolt. I could drill about halfway through swingarm. More hammering with punch tool still wouldn't break it free. Given I drilled out most of the bolt from the small side hole, I figured case splitter tool would probably be able to break it free and at least get the cases split since there wasn't much bolt left on that small side hole. It did break free, but was still unable to get the case fully split as the bottom below the shifter box was still stubborn and refusing to split. cases were open at the top near the reed valve opening and narrowed down to stuck closed at the bottom. Figured it was a seized locator pin preventing it from splitting on the bottom, but there is no locator pin in the hole! Its got to be just decades of dried up oil and paper gaskets acting as cement. So I got it open enough to shoot some pb blaster into the case and left it propped up so the pb blaster would eat away at whatever is refusing to give on the bottom side. I'll check back tomorrow and see if some more torque with the case splitter and rubber mallet can break free that last bit hanging on. Worst case I think I'm gonna have to find a welder to weld the hairline fracture on the round below that bolt hole on small side.

The other half where the bolt is still stuck through the meat of the swingarm with the bolt head, I'm gonna have to redo all the drilling with more space available from the small side removed. So that will take some time. I'm also hoping I did not drill on an angle and start to drill into the case itself and not the bolt!

Haven't started on the broken exhaust bolt fragments yet cause I just want to get the case split first and make sure its still usable before going to town on the thicker bolt. I was wishing I had an upright drill station instead of the handheld drill during this operation.

I'm cursing the person who did not coat these bolts with grease before installing! I've started profusely covering all bolts when I install them onto my engines prior to this as I had seen somewhere that this could happen.

I got to the same place you did with a very rusty vbb case. The problem that the crank had come out with the bearings a little on each side. So the case was opening up but not enough to split. It rocked backed and forth just like yours. What finally did it was pounding the crank out from the clutch side with lots of heat. Rocking the fly side half back and forth didn't help. Prying at the bottom lugs didn't help. Cutting that big through bolt and studs didn't help. Just made more work to fix it.The crank had to come out from one side or the other. So it wasn't something at the bottom, it was just the crank. The case splitter didn't do shit for me either. Even on the next case I did because it tapped open with a rubber mallet just like on da Yootoob.

Last edited by orwell84 on Fri Oct 29, 2021 2:37 pm; edited 1 time in total

Well I kinda did start to work the crank out through the usage of the splitter tool, but I was coming at it from the fly side. My next step tomorrow was to try attacking it with splitter tool from clutch side. It really is only about an inch or so of sealing surface still hanging on. PB Blaster helped most of the stuck side break free after only a few minutes. My guess is going back to it tomorrow after shooting a ton of that blaster down into the case is enough to get it to a point it will break free with a few more taps and the torque of the splitter tool.

BTW, I don't even want to think about what would be needed to get the cylinder studs removed without doing damage to the case threads. Those studs look equally crusty seized. Hoping they are good enough to just leave in with some cleanup.

Sounds like you're getting there. One side or the other has to come out completely or it just won't split. Sounds obvious but that's what it comes down to

What an unforgiving POS!

Finally got the p125 split. Three Days of checking on it, torquing it with splitter while hammering away full strength at the little meat tab next to the locator pin, then spraying with pb blaster and leaving it for 24 hrs.

The last gasp was a solid 30 min with the torch an inch away from the locator pin spot just burning it as hot as I could get it while occasionally cranking the splitter tighter. Finally heard it give then went back to the punch tool and hammer on that meat section next to locator pin until it worked itself apart.

Did a number on the meat section, but I'm guessing that's why it's there. I made sure not to touch the actual sealing surface next to it.

Can finally strip the cases and finish removing those seized bolt fragments.




Meaty section bruised from aggressive effort to split this ungrateful pig.

The long case bolt through the thickest section of case. Or what's left of the half I couldn't drill through with the small side still on

It will need some minor welding after that operation though...

I'm assuming it would be a risky and foolish thing to attempt to weld that crack with my basic flux core welder and having never done aluminum before! Cm22 I'm not that ambitious just yet.

Great work on the drilling. Can smell the copper grease that caused that corrosion from here.
When you get the bolt out, the later models have a plated bolt and no further issues.

I don't know if flux aluminum wire is a thing (yet), but if so, you could grind that out and weld it, for sure.

I'm already looking at what's going to be required to get my aluminum welding going, whether mig or tig. I think I should be adding reinforcement plates to all my motors.

It's a great feeling when it finally lets go, isn't it?

It's amazing how sturdy they are and how well they clean out. My VW bus cases would never survived the brute force and ignorance inflicted on my vbb case. Same sort of damage as yours. It cost me 60$ to have it welded but I had a big crack in the leaf blower section.

I have been looking into aluminum brazing to build up the cases for porting, though I'm not sure how well it would hold up. Aluminum welding with MIG is also possible with Argon gas, a spool gun and liner. That still leaves milling the case parting lines and cylinder spigot flat. It probably makes a lot more sense to ship it to someone who can do the welding and is already set up to do the machining.


My VBB case...the barn door door stop

After a round of soda blasting

Cast aluminum pretty well requires TIG.
JB weld is a tried and proven method for helping with porting when needed.
Cases are low compression - and as long as its not being forced to do your load bearing - it will hold a good long while.
Surface prep is critical.

Swiss:
With breaks like that - its best tackled by actually grinding the broken piece off - and using filler rod to build up the area and reshaping.

Unfortunately - looks like that crack propagated down the side of the case.
Highly repairable by someone that knows what they are doing.
Will require them to cut a v groove and weld up the crack as well.

well the large half of that case with the rusted exhaust bolt and case bolt is at a machinist for the past two weeks, who said he would try to remove them but said it would be a while cause its such a cheap project for him!

I'll call in another week or two and see if he felt like giving it a shot.

Meantime.. like a lot of others lately.. trying to deal with the nasty rusted gas tanks. I've got 3 I haven't wanted to deal with for a while. The original from my v100 which the guy had a new replacement I threw in, the P125 bike I picked up a couple years ago.. and this orange stella i picked up over the summer. Orange stella gas tank is pristine on the outside with paint still on it, but the inside is seriously nasty. I couldn't get the fuel taps out of either the v100 or the stella tanks so I left both outside filled with vinegar for the past week. Didn't help much getting rid of all the rust inside, but it did start to weaken the rust enough so I was able to remove the fuel taps in both tanks.

I'm waiting on a battery charger and sodium carbonate to come tomorrow so I can start seriously attacking the rust with electrolysis. Stella tank I'll fill with solution and clean the inside leaving the paint on outside untouched. V100 rusty tank I was thinking of submerging in a container and hopefully remove all the rust including on the cap and exterior. But since the original cap is on with a cotter pin and not the correct original pin, I may just do the same and remove the cap to submerge the cap on its own for rust removal.

Can't hurt to try.






stella.. dumped a bunch of baking soda on it and in it to neutralize the vinegar.

you'll be amazed at how well electrolysis works on those. None of them look materially worse than my GL's tank and it cleaned up nicely.

I'd suggest starting out with a wire brush on an extender for your drill and knocking as much of the rust loose as you can. That'll save a lot of time and remove an astounding amount of what's in there, along with the gas & oil that's probably soaked into it.

I didn't think of that until after I'd already been at it for a while (and was getting frustrated with the lack of progress), but once I did, the electrolysis knocked out what was left in a few hours.

I did wind up getting a new gas cap, but probably could have saved the old one...if I hadn't lost it in my workshop at that critical juncture...


brush-on-a-stick

You may have issues using a modern smart battery charger VS power supply, unless charger is dumb, it looks for a battery connection by checking voltage and internal battery resistance. Working on wheelchairs sometimes I have to connect dead batteries to a power supply for a few minutes to get minimum voltage up then move battery to a normal charger.

I ran my charger across a 12V battery to get around that problem. That tricked the charger just fine

I searched for one that has manual mode. Hopefully it works.

And I will take everyone's advice. Lml oiler gas tank too big for dryer. I'll straight electrolysis that one. P125 is the least rusty insides, I'll dryer tumble that one. V100 is the worst. I'll wire wheel on drill flexi extension to get rid of as much as I can, then dryer tumble then electrolysis.

i guess my posting disappeared?

I forgot about the oiler tanks. I did it with both a non-oiler T5 tank, Lammy tank, and Honda CB160 tank. They were all full of rust, and then came out shiny bare metal after the process. All of those are a bit smaller without that long tube. Ummm....perhaps a trip to the laundromat with a pocket full of quarters?

ahah. I doubt my local laundromat would be pleased to see me throwing a cardboard box with god knows what into one of their jumbo driers!

Well I'll be damned. Was sitting here working from home and decided to try tumbling the p125 tank in the dryer while I was waiting for co-worker to send me stuff to do.

This is the cleanest tank but it seemed to have dried varnish on it, not really rust so I guessed it would clean up quicker and easier with tumble.

small handful of rocks into the tank and in a somewhat large box that almost didn't fit into dryer. 10 minutes later and it knocked off about half of the junk inside the tank turned it to dust! I'm guessing another 30 min and it will be spotless.

Unfortunately not sure if the cardboard box will survive.. and hopefully the dryer doesn't get damaged cause its banging around quite a bit in there!

EDIT: and just as i posted that, i heard rocks rolling around loose in the dryer. bung popped out and the box fell apart! I'll finish this one off with chandlerman's wire brush on flexi rod suggestion since there is not much left to the varnish. The rest I will use the wire brush extension trick instead of the dryer as it dented the dryer barrel and I don't feel like getting yelled at for breaking that thing!

snort laugh.
you will never look at that dryer barrel the same.
someday - someone - will ask out loud:
wtf did someone put in here?

You have the tape up the box super well so it doesn't break apart! I also throw in a couple large blankets randomly into the dryer to help soften the blows from the box. There will definitely be thumping noises, but if there's any banging, then there needs to be more padding.

remember stone washed jeans from the 80's? Next time throw in a pair of your 501's in order to get that "look".

I guess having a pristine gas tank is a thing here. I don't know if Vespas have an in line fuel filter. Mine didn't, but it seems like a good idea.

The key here is seems.

I fixed a scooter for a local - removed the inline fuel filter and replaced the fuel line. The difference in height between the tank and carb is very little so the back pressure from the inline filter was just enough to make it not wanna run consistently...

First attempt on v100 super rusty tank. Didn't use wire wheel as the one I have doesnt fit in the opening.

Bubbling away. I'll check it in 6 hrs and see if there is any noticeable improvement.

Since the guy I bought it from already bought a brand new replacement tank which works fine, this is more experiment on this extremely rusty tank to see how much it is able to bring the tank back to life.

LML and P125 tanks I'll do better prep work with wire brush inside prior to any electrolysis. In fact I think the P125 tank I previously posted image above wont even need electrolysis. Just a pass over with wire brush.

Lesson #1. Size of sacrificial piece can severely slow down the process as it acquires rust coating. All I have is this quarter inch rod lying around so I used that since it was easy to drill a hole in wood and bend it so that it wouldn't move and ground out. Unfortunately the small rod only takes an hour to get fully coated and once that happens the amps go almost to nothing. Starts at 2.6a and after an hour its down to 0.6a.

Yup. It's like I said, it's all about surface area. Everyone says to use rebar, but if you can get your hands on some good-sized chunks of cast iron, those'll work better and longer.

6 hours later and despite going down to really low amps it did a damn fine job with zero cleanup so far. Its still covered but I can see bare metal spots peaking through everywhere now. Just ordered a couple of 1" dia hex shank wire brushes so that I can get in there and physically knock most of that off before another round of lectric.

post 1 week vinegar soak:



6 hrs electrolysis with zero physical removal.

Quick wire brush and power wash and this tank is almost perfect.

Doing another 6 hr shock treatment to clean up any spots I couldn't reach with brush or power wash wand. Should be perfect after that!

Amazing how well this stuff works.. and now another task no longer out of reach or seemingly unachievable.

tank looks great

wow that is astonishing results

Very nice. Very nice indeed!