OP
UTC

Member
Small door 90
Joined: UTC
Posts: 7
Location: Washington D.C
 
Member
Small door 90
Joined: UTC
Posts: 7
Location: Washington D.C
UTC quote
I have a I think 1967 ( I can get exact year ) sprint 90. Guy who gave it to me took the spark plug out and never put it back in. the Maryland humidity did it's job.
I remove the motor and head had it soaking in all kinds of miracle liquid and ATF fluid for the last two months. Motor in neutral hit it with a soft blow hammer and a chunk of wood no luck.
I have seen a video of mixing gasoline and ATF Fluid, lighting it on fire for an hour and then hitting it.
Scooters west said something about cutting the Cylinder and connecting rod off? My manual says take the case apart. I know the reason that this bike got parked because the stater was completely trashed. I was hoping to free the piston may be replace the cylinder and piston replace all the cables wire harness rebuild stater put it all back together and see how it goes. The odometer reads 4000 miles and I'm thinking it's very possible the motor has never been removed or worked on.
It hasn't been ran since the 80s. The guy who gave it to me was the second owner the original owner s his wife's father.
Help please! New to vespa and this forum.
Thanks
@gmontag avatar
UTC

Hooked
Joined: UTC
Posts: 487
 
Hooked
@gmontag avatar
Joined: UTC
Posts: 487
UTC quote
You may need to press the piston out. Go easy.

If this is really a 90 (super?) sprint I'm gonna need to see pictures please.
@burt37 avatar
UTC

Addicted
GTS 300 SS BB
Joined: UTC
Posts: 617
Location: QLD AUS
 
Addicted
@burt37 avatar
GTS 300 SS BB
Joined: UTC
Posts: 617
Location: QLD AUS
UTC quote
Re: 90 sprint froze piston help
Jonathanfay wrote:
I have a I think 1967 ( I can get exact year ) sprint 90. Guy who gave it to me took the spark plug out and never put it back in. the Maryland humidity did it's job.
I remove the motor and head had it soaking in all kinds of miracle liquid and ATF fluid for the last two months. Motor in neutral hit it with a soft blow hammer and a chunk of wood no luck.
I have seen a video of mixing gasoline and ATF Fluid, lighting it on fire for an hour and then hitting it.
Scooters west said something about cutting the Cylinder and connecting rod off? My manual says take the case apart. I know the reason that this bike got parked because the stater was completely trashed. I was hoping to free the piston may be replace the cylinder and piston replace all the cables wire harness rebuild stater put it all back together and see how it goes. The odometer reads 4000 miles and I'm thinking it's very possible the motor has never been removed or worked on.
It hasn't been ran since the 80s. The guy who gave it to me was the second owner the original owner s his wife's father.
Help please! New to vespa and this forum.
Thanks
I really don't see how ATF fluid could possibly help here..
What you need to use is penetrating oil like Inox, (a.k.a. possum piss) and leave it in for days..

You need to take time on jobs like this. It Is not an instant miracle..
@christopher_55934 avatar
UTC

Ossessionato
2007 Stella 225
Joined: UTC
Posts: 3547
Location: Rochester, Minnesota
 
Ossessionato
@christopher_55934 avatar
2007 Stella 225
Joined: UTC
Posts: 3547
Location: Rochester, Minnesota
UTC quote
If its that old and has been sitting that long, I would bet the rubber seals are rotten. Probably going to need to split the case and put in new gaskets and seals anyway.

What miracle fluids have you been using? Any actual penetrating oil? I've soaked rusted together parts in regular oil for days no luck. Bought a gallon of penetrating oil and soaked the parts they came apart in a few hours.

Please check the flash point of what your using, you can create a heated bath on a electric burner on low heat to help loosen things up also.

This might help also.

https://www.homedepot.com/p/XtremepowerUS-110-Volt-Electric-4-5-ft-Corded-Concrete-Vibrator-with-35-mm-Vibrating-Poker-and-1-5-m-Hose-61063-H/313076023
UTC

Addicted
BV 350
Joined: UTC
Posts: 943
Location: Nebraska
 
Addicted
BV 350
Joined: UTC
Posts: 943
Location: Nebraska
UTC quote
If
If you are replacing the piston and cylinder anyway (and you probably need to) I'd take a propane torch and go around the outside of the cylinder where the piston is stuck. Likely the different thermal expansion rates would break the piston free. At this point more important to preserve the connecting rod and crank, although I agree that the crank seals are almost certainly trash. And if the piston is low enough that the ports to the crankcase are open, good chance the crank is trash too. At that point might just want to look for another engine.

Unless you are in love with that specific scooter, or really enjoy tinkering, I'd pass on it. You will have far more wrapped up in time and money than the scooter will be worth when you are done.
@gmontag avatar
UTC

Hooked
Joined: UTC
Posts: 487
 
Hooked
@gmontag avatar
Joined: UTC
Posts: 487
UTC quote
so it it a Sprint?
a Super?
a Super Sprint?

big difference between the latter and former.

You said "90" so this is very confusing.
OP
UTC

Member
Small door 90
Joined: UTC
Posts: 7
Location: Washington D.C
 
Member
Small door 90
Joined: UTC
Posts: 7
Location: Washington D.C
UTC quote
I guess it's just a plain old small frame 90.
Forum member supplied image with no explanatory text
UTC

Molto Verboso
1958 Allstate 177VMC, 1962 Allstate, Yamaha Vino 70cc
Joined: UTC
Posts: 1801
Location: Philadelphia
 
Molto Verboso
1958 Allstate 177VMC, 1962 Allstate, Yamaha Vino 70cc
Joined: UTC
Posts: 1801
Location: Philadelphia
UTC quote
I had to cut my cylinder and piston off my VNA. Soaked it forever and got no movement. Used my sawzall and chopped the cylinder then had to chisel between the piston and the cylinder to break it free. Cylinders and pistons are replaceable so if you gotta cut it out it's not the end of the world.

I'd suggest splitting the cases first though and trying to remove it that way before you cut it though.
@oopsclunkthud avatar
UTC

Banned
3:5
Joined: UTC
Posts: 8909
Location: San Francisco
 
Banned
@oopsclunkthud avatar
3:5
Joined: UTC
Posts: 8909
Location: San Francisco
UTC quote
even in the very worst case where the crank, piston, cylinder have all become one, you can split the cases without needing to cut anything.
@christopher_55934 avatar
UTC

Ossessionato
2007 Stella 225
Joined: UTC
Posts: 3547
Location: Rochester, Minnesota
 
Ossessionato
@christopher_55934 avatar
2007 Stella 225
Joined: UTC
Posts: 3547
Location: Rochester, Minnesota
UTC quote
Not sure on cylinder costs and your plans. If you can't get them separated, would it be worth cutting the piston center out, with a torch to get the cylinder off? Then you could break the piston apart bore the cylinder up to the next piston size?
@burt37 avatar
UTC

Addicted
GTS 300 SS BB
Joined: UTC
Posts: 617
Location: QLD AUS
 
Addicted
@burt37 avatar
GTS 300 SS BB
Joined: UTC
Posts: 617
Location: QLD AUS
UTC quote
Christopher_55934 wrote:
If its that old and has been sitting that long, I would bet the rubber seals are rotten. Probably going to need to split the case and put in new gaskets and seals anyway.

What miracle fluids have you been using? Any actual penetrating oil? I've soaked rusted together parts in regular oil for days no luck. Bought a gallon of penetrating oil and soaked the parts they came apart in a few hours.

Please check the flash point of what your using, you can create a heated bath on a electric burner on low heat to help loosen things up also.

This might help also.

https://www.homedepot.com/p/XtremepowerUS-110-Volt-Electric-4-5-ft-Corded-Concrete-Vibrator-with-35-mm-Vibrating-Poker-and-1-5-m-Hose-61063-H/313076023
Here is a new idea..

Use penetrating oil.. Laughing emoticon

Now regarding the Concrete agitator..??

Are you for real???

You do know that we have proper tools for this job...

And if you need to cut either the piston or the rod to fix it, it does tell a lot about your mechanical skills...

You got to be careful, lots of people read those post and someone may believe you..

Just saying..
@langolson avatar
UTC

Hooked
Vespa 125 VMA, Vespa SS 180
Joined: UTC
Posts: 208
Location: Minneapolis, MN
 
Hooked
@langolson avatar
Vespa 125 VMA, Vespa SS 180
Joined: UTC
Posts: 208
Location: Minneapolis, MN
UTC quote
You have an early Vespa 90. The early Vespa 90s have a smaller cylinder base, so if you cut the cylinder or damage it during removal, it is not easily replaced. Just FYI.
OP
UTC

Member
Small door 90
Joined: UTC
Posts: 7
Location: Washington D.C
 
Member
Small door 90
Joined: UTC
Posts: 7
Location: Washington D.C
UTC quote
I didn't think aftermarket pistons /cylinders were hard to come by. I didn't want to split the case but WTF I'm this far into it and I like the suggestion of taking the frozen piston/jug to a hydraulic press. However,
Still not convinced I can split the case without the jug off the studs.
@christopher_55934 avatar
UTC

Ossessionato
2007 Stella 225
Joined: UTC
Posts: 3547
Location: Rochester, Minnesota
 
Ossessionato
@christopher_55934 avatar
2007 Stella 225
Joined: UTC
Posts: 3547
Location: Rochester, Minnesota
UTC quote
Burt37 wrote:
Christopher_55934 wrote:
If its that old and has been sitting that long, I would bet the rubber seals are rotten. Probably going to need to split the case and put in new gaskets and seals anyway.

What miracle fluids have you been using? Any actual penetrating oil? I've soaked rusted together parts in regular oil for days no luck. Bought a gallon of penetrating oil and soaked the parts they came apart in a few hours.

Please check the flash point of what your using, you can create a heated bath on a electric burner on low heat to help loosen things up also.

This might help also.

https://www.homedepot.com/p/XtremepowerUS-110-Volt-Electric-4-5-ft-Corded-Concrete-Vibrator-with-35-mm-Vibrating-Poker-and-1-5-m-Hose-61063-H/313076023
Here is a new idea..

Use penetrating oil.. Laughing emoticon

Now regarding the Concrete agitator..??

Are you for real???

You do know that we have proper tools for this job...

And if you need to cut either the piston or the rod to fix it, it does tell a lot about your mechanical skills...

You got to be careful, lots of people read those post and someone may believe you..

Just saying..
I had a concrete vibrator around the house, from when I poured some concrete walls. I tried it on some rusted parts and it helped vibrate them lose. Didn't have an ultrasonic bath big enough. Worked the same as when I used an air hammer or chisel with a blunt end to remove king pins from a 1950 Ford truck. Beat on those pins for hours, brand new compressor and air chisel had then out in 5 seconds. You may laugh but sometimes you have to think outside of the box.
@burt37 avatar
UTC

Addicted
GTS 300 SS BB
Joined: UTC
Posts: 617
Location: QLD AUS
 
Addicted
@burt37 avatar
GTS 300 SS BB
Joined: UTC
Posts: 617
Location: QLD AUS
UTC quote
Christopher_55934 wrote:
I had a concrete vibrator around the house, from when I poured some concrete walls. I tried it on some rusted parts and it helped vibrate them lose. Didn't have an ultrasonic bath big enough. Worked the same as when I used an air hammer or chisel with a blunt end to remove king pins from a 1950 Ford truck. Beat on those pins for hours, brand new compressor and air chisel had then out in 5 seconds. You may laugh but sometimes you have to think outside of the box.
Trust me, I wasn't laughing at all... I have no problem in thinking out of the box, but we got to draw a line somewhere... Laughing emoticon

Normally people will got for impact drivers, bench or hydraulic press, but if that shiny concrete vibrator is giving you a good result, who am I to judge??
OP
UTC

Member
Small door 90
Joined: UTC
Posts: 7
Location: Washington D.C
 
Member
Small door 90
Joined: UTC
Posts: 7
Location: Washington D.C
UTC quote
Guess I'm going to try one more time with some kind of impact method. Get the special tools I need to split the case.
UTC

Jet Eye Master
PX221 MHR, O tuned PX200, PX181 Quattrini and some motorbikes
Joined: UTC
Posts: 4438
Location: London UK
 
Jet Eye Master
PX221 MHR, O tuned PX200, PX181 Quattrini and some motorbikes
Joined: UTC
Posts: 4438
Location: London UK
UTC quote
I was wondering if you had tried hitting it. Very hard with a brass drift usually does the required damage.

Plenty of cheap kits available (all very tunable to your purpose). Measure the stroke length and spigot size once the cylinder is off, to be sure to get the right one. So many small frame variations.
⚠️ Last edited by Jack221 on UTC; edited 1 time
@socalguy avatar
UTC

bodgemaster
63 GL, 76 Super (x2), 74 Primavera (x2), 79 P200, 06 Fly 150
Joined: UTC
Posts: 7070
Location: So Cal
 
bodgemaster
@socalguy avatar
63 GL, 76 Super (x2), 74 Primavera (x2), 79 P200, 06 Fly 150
Joined: UTC
Posts: 7070
Location: So Cal
UTC quote
Jonathanfay wrote:
Still not convinced I can split the case without the jug off the studs.
Back the cylinder studs out of the case using the double nut method. The case can then be spilt and the frozen crank+piston+jug can be removed as a unit. It's done all the time.
Forum member supplied image with no explanatory text
@burt37 avatar
UTC

Addicted
GTS 300 SS BB
Joined: UTC
Posts: 617
Location: QLD AUS
 
Addicted
@burt37 avatar
GTS 300 SS BB
Joined: UTC
Posts: 617
Location: QLD AUS
UTC quote
Jonathanfay wrote:
Guess I'm going to try one more time with some kind of impact method. Get the special tools I need to split the case.
Perhaps it is time for you to post some good quality pictures, of the motor, so that we may get to see where you are with this issue..

So far, you haven't given many useful information or details for other to help you..

I guess what I'm trying to say is:
Forum member supplied image with no explanatory text
OP
UTC

Member
Small door 90
Joined: UTC
Posts: 7
Location: Washington D.C
 
Member
Small door 90
Joined: UTC
Posts: 7
Location: Washington D.C
UTC quote
I can certainly post pictures of the motor. you bet. Thanks for the suggestion! I have been trying to relay to soak I've never been part of a forum so advice on that is helpful as well. I can't find anybody around DC to connect with for Hell I don't even think we have a scooter shop that still works on vintage stuff. Pictures coming
@burt37 avatar
UTC

Addicted
GTS 300 SS BB
Joined: UTC
Posts: 617
Location: QLD AUS
 
Addicted
@burt37 avatar
GTS 300 SS BB
Joined: UTC
Posts: 617
Location: QLD AUS
UTC quote
Jonathanfay wrote:
I can certainly post pictures of the motor. you bet. Thanks for the suggestion! I have been trying to relay to soak I've never been part of a forum so advice on that is helpful as well. I can't find anybody around DC to connect with for Hell I don't even think we have a scooter shop that still works on vintage stuff. Pictures coming
Don't worry about that mate.. We all had to start somewhere..

Reason for asking for pictures is because depending on the piston position in relation to the stroke, there could be different options available to you..

If the piston is currently in the BDC position, you can't really hit it...

Get some pictures of the top of the piston and if possible and the piston is not at the TDC a picture from the outlet (exhaust)..

If the piston is somewhere in the middle does the crank rotate??? (obviously the cylinder will move up and down with the piston)

Are the studs rusted in or free. Can you remove them using the double nuts system mentioned by SoCalGuy?? (and do you know how to do it?)

These are the kind of information and pictures we need to be able to help..

The better the pictures the easier it is for everybody...
@oopsclunkthud avatar
UTC

Banned
3:5
Joined: UTC
Posts: 8909
Location: San Francisco
 
Banned
@oopsclunkthud avatar
3:5
Joined: UTC
Posts: 8909
Location: San Francisco
UTC quote
if I recall the 90 didn't have studs, it just uses bolts to mount the cylinder. much easier to remove.

Things that have to be removed before splitting the cases:

1. flywheel
2. clutch and drive gear
3. cylinder bolts

From there it should come apart with the stuck piston, cylinder, and crank as one item.
⬆️    About 2 months elapsed    ⬇️
OP
UTC

Member
Small door 90
Joined: UTC
Posts: 7
Location: Washington D.C
 
Member
Small door 90
Joined: UTC
Posts: 7
Location: Washington D.C
UTC quote
Thanks everyone. Last post was spot on and yes the nuts and cylinder came right off.
So now I'm trying to figure out where to go with this. I wish I could've freed the piston just put the motor back in and see how it ran. Obviously not the case so I expect to do the following
- Separate case remove rod, piston, cylinder.
- Press out piston
now where to go.?
The reason this thing stopped working is because the stater needs to be completely rebuilt.
So I guess one option is just replace minimal Internal misc parts like crank seal and bearings?
I'd really appreciate a suggested rebuild parts list.
I'm gonna call the machinist but I'm guessing it's not worth Re boring the cylinder if I have to get new piston and rings. new cylinder/ piston kits look available for my model.
I did see a performance upgrade kit but looks like I probably would have to get a bigger carburetor as well. This motor is completely original stock all parts so I guess I should probably keep it that way. The bike itself is perfect with one dent on the fender very minimal surface rust on floorboards. This will be a patina bike with the original 1960s inspection stickers etc. I weigh 170 live in a fairly flat area in DC and will probably just be going to the grocery store small errand run stuff .
Was also wondering if anyone knows anything about this Austrian Stita aftermarket Vespa parts company. They have a brand new complete stater plate for around $200. Scooters west gave me a vague rebuild price for mine which Sounded like a neighborhood of $250+ shipping and handling.
Then I'd order the other usual parts all new cables probably a wire harness and go to town.
Little of my history. It's been a long time but I used to be a VW motor head and rebuilt a few engines so I'm a little rusty but generally speaking I am mechanically competent for this project.
Forum member supplied image with no explanatory text
⬆️    About 1 year elapsed    ⬇️
OP
UTC

Member
Small door 90
Joined: UTC
Posts: 7
Location: Washington D.C
 
Member
Small door 90
Joined: UTC
Posts: 7
Location: Washington D.C
UTC quote
We'll I'm back.
Case split, broken down and cleaned. Need to take bearings out but that's it. So have the following questions.
Realizing I have the less common small door v9a and subsequent pain with parts😵‍💫.
Hydraulic press got the piston out. No scoring but can definitely feel a lip at the top of the cylinder. Guessing a rebore in order?
Crank end of rod has a pretty good amount of side play No movement top to bottom. Piston rod end feels like it's got a little slop both directions wrist pin came out with a very light tap. Rings came out in pieces. A little corrosion froze them. Don't know what tolerances are but doesn't seem promising.
I know the 95 year old one owner who gifted it to me and he babied it. All gears in top shape. Gear selector will be replaced a little rounded but doesn't show any crazy wear.
So what direction to go.
First scenario
If Crank is o.k. Piston and jug o.k.(optimistic) = hone, new rings put it all back together.
Crank not o.k. Rebuild? Copper bearings available? Sounds expensive. Probably not available new.
New piston. rebore with first over. Again Parts look like they are all specific because pre 2500 90 model and hard to locate.
I would like keeping this scoot all original. I've put a bunch of time into breaking down this motor.

Plan b would be to machine case to accept wider piston spigot/ allow post 2500 parts maybe upgrade to 125cc?
(Exhaust, carburetor, crank, top end) plus standard rebuild parts on top of that. Also sucks because I have every original part to this Vespa and even some NOS spares. The scoot was free, solid, with one small dent on fender, just want to keep it patina. not sure I want to dump $2000 into it. Don't want to buy another Vespa. The one I have seems like it was meant for me sent by the cosmos. Including a few pics but nothing to noteworthy here really. Just a little corrosion on case where fly wheel spins in. Some blueing on crank counter weight where pin goes through ( guess this is from the heating process to get the pin in there during manufacturing but maybe not?)
Cylinder. Can't see any scoring. Of course doesn't matter if I have to re-bor it I'll need new piston anyhow.
Case
Case
Forum member supplied image with no explanatory text
Forum member supplied image with no explanatory text
Forum member supplied image with no explanatory text
UTC

Veni, Vidi, Posti
Joined: UTC
Posts: 6486
Location: Tega Cay, SC
 
Veni, Vidi, Posti
Joined: UTC
Posts: 6486
Location: Tega Cay, SC
UTC quote
Jonathan, I don't know squat about small frames, but kudos to you for taking on this project and all the work you have done so far. I was given a small frame 90 as well with cut up frame, but decided to pass along the project to a local scooter guy as I was not willing to drop $1500 plus to fix the body and upgrade the engine. There are people on here that can give you proper advice, of course, but in the end, I think you should do want you want to do with it. The frame looks to be in great shape and the 90 engine is not going to win any races, but it will good to putt around town. I guess it all depends on what you want to use it for. Good luck, I'll be following you thread.
DoubleGood Design banner

Modern Vespa is the premier site for modern Vespa and Piaggio scooters. Vespa GTS300, GTS250, GTV, GT200, LX150, LXS, ET4, ET2, MP3, Fuoco, Elettrica and more.

Buy Me A Coffee
 

Shop on Amazon with Modern Vespa

Modern Vespa is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com


All Content Copyright 2005-2024 by Modern Vespa.
All Rights Reserved.


[ Time: 0.1164s ][ Queries: 29 (0.0766s) ][ Debug on ][ 313 ][ Thing One ]