OP
@dorydan avatar
UTC

Member
ET4 150cc 2002
Joined: UTC
Posts: 5
Location: US
 
Member
@dorydan avatar
ET4 150cc 2002
Joined: UTC
Posts: 5
Location: US
UTC quote
2002 ET4 150cc 3000 easy miles. Had been running fine. Went to start it the other day and it makes a single "clunk" when I press starter but will not turn over or crank the engine in the least bit. What I have done so far:
1. charged the 1 year old battery - no change
2. borrowed another battery from different bike - no change
3. jumped with car - no change
4. pulled relay - no luck finding another locally - 12v applied to primary and it definitely clicks like a good little relay should and it closes the secondary terminals - no change
5. removed starter, lightly buffed brushes and commutator with 600 weight sandpaper, cleaned and reassembled. BTW brushes looked good. - no change.
6. wiring looks good. no loose connections found.
7. started to get mad

I feel the starter is getting good juice because it makes a pretty good "clunk" every time I hit the button. It is almost as if the engine is seized and the starter just can't turn it but I know that is super low probability (ran fine, oil good, no previous signs of overheating). Unfortunately, I can't test this with the kick start because the return spring broke a couple years ago. I tried to connect a jumper between the positive battery terminal and the positive stud on the starter to rule out relay or upstream wiring issues but the sparks got in the way javascript:emoticon('8)')

Is it possible the relay closes but can't carry enough current, or maybe the starter runs but is for some reason suddenly too weak..... any suggestions appreciated!

Thanks, Dorydan
@jimc avatar
UTC

Moderaptor
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: UTC
Posts: 44221
Location: Pleasant Hill, CA
 
Moderaptor
@jimc avatar
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: UTC
Posts: 44221
Location: Pleasant Hill, CA
UTC quote
Open up the transmission case and ensure the engine can be turned by hand. If so, then double check the Bendix gear isn't jamming somehow on the flywheel.
OP
@dorydan avatar
UTC

Member
ET4 150cc 2002
Joined: UTC
Posts: 5
Location: US
 
Member
@dorydan avatar
ET4 150cc 2002
Joined: UTC
Posts: 5
Location: US
UTC quote
Thanks for the advice Jim. I think this might be a case where hoofbeats actually do herald zebras!

i pulled the transmission case and pulled the variopah mechazini thing. Nothing jammed behind it. Very clever design. "Flywheel" teeth all fine. Pulled Bendix and it is also fine. Big Problem: put nut and large wrench back on end of crank and, only with great force, was able to turn it a few degrees while generating a nice metallic scraping sound.

Sooo, i am thinking next step is to take of the head and look for broken valve, piston ring, etc... Hard to believe that could be the problem as the bike has only ~3k well maintained miles was running fine and without any abnormal noise when i took it to work. Came out after work, pressed start button and CLUNK!

Any other recommendations welcome as i am not all that enthusiastic about digging into the cylinder. Also, Haynes vs genuine Vespa repair manual- is one clearly better?

Thanks!
@jimc avatar
UTC

Moderaptor
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: UTC
Posts: 44221
Location: Pleasant Hill, CA
 
Moderaptor
@jimc avatar
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: UTC
Posts: 44221
Location: Pleasant Hill, CA
UTC quote
Ouchy.

It's engine out time. It's less of a huge deal than you might think if you've not done it before. The engine will sit on the bench quite happily on the centre-stand and a small block of wood to persuade it not to topple over.

Manuals - all you really need to know are the torque wrench settings for the head bolts etc. There are several videos around showing how to dismantle if you're not willing to just dive in.

With your symptoms don't spend any money on parts until you've some idea if it's worth fixing. A broken crankshaft might indicate a replacement engine from a write-off might be the better bet.

There are a couple of pro-tips: hang a weight on the timing chain (zip-tie a wrench to it) so it doesn't fall inside and kink. Also, ensure the chain tensioner is fully set at 'slack' before re-fitting, otherwise you'll be waiting for a new one to arrive...

Good luck, it sounds as if you're capable of tackling this.


Do NOT start the engine without the variator installed.
@greasy125 avatar
UTC

Sergeant at Arms
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: UTC
Posts: 14995
Location: The state of insanity, SoCal
 
Sergeant at Arms
@greasy125 avatar
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: UTC
Posts: 14995
Location: The state of insanity, SoCal
UTC quote
Before pulling the engine and tearing down, check the flywheel side for debris. Occasionally something will get sucked in or dropped and gum up the works.

Worth a shot before a complete test down.

Btw, hows the oil look? Is the prefilter full of trash?

Good luck!

-g
@jimc avatar
UTC

Moderaptor
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: UTC
Posts: 44221
Location: Pleasant Hill, CA
 
Moderaptor
@jimc avatar
The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
Joined: UTC
Posts: 44221
Location: Pleasant Hill, CA
UTC quote
^^^^ Very good points! It could just be a stator magnet has exploded, or something else that side.

So keep digging.
@greasy125 avatar
UTC

Sergeant at Arms
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: UTC
Posts: 14995
Location: The state of insanity, SoCal
 
Sergeant at Arms
@greasy125 avatar
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: UTC
Posts: 14995
Location: The state of insanity, SoCal
UTC quote
jimc wrote:
^^^^ Very good points! It could just be a stator magnet has exploded, or something else that side.

So keep digging.
It's a remote possibility, but as long as we're throwing out WAG I figured might as well toss one that I've seen

I'd also pull the valve cover and just have a quick look see. That'll tell you loads what you're up against because you can see and inspect the valves, cam, chain.

Yank the plug and see if it's covered in metal or melted. Then go from
There.

-g
OP
@dorydan avatar
UTC

Member
ET4 150cc 2002
Joined: UTC
Posts: 5
Location: US
 
Member
@dorydan avatar
ET4 150cc 2002
Joined: UTC
Posts: 5
Location: US
UTC quote
Thanks for the encouragement and advice guys. sounds like you are as curious as i so i'll keep you posted. pretty busy so it will probably be a couple weeks...
⬆️    About 1 month elapsed    ⬇️
OP
@dorydan avatar
UTC

Member
ET4 150cc 2002
Joined: UTC
Posts: 5
Location: US
 
Member
@dorydan avatar
ET4 150cc 2002
Joined: UTC
Posts: 5
Location: US
UTC quote
My Sea Turtle swims again!

Guys, you nailed it. I got the tool to pull the "flywheel" (I call these things rotors but whatever) and take a look at what I found. I can't believe I didn't hear anything! Put the new rotor and stator in and, since the other side open, I put in some new rollers and a new belt. Purrs like a kitten.

I was going to use the variator tool to hold everything quiet while a torqued the flywheel nut but then I wondered if the crank would like that. Instead, I fashioned this tool from 1/8 scrap aluminum and it worked really well. It butts up against the muffler bracket when the nut is tightened so I could concentrate on the torque wrench.
Forum member supplied image with no explanatory text
Forum member supplied image with no explanatory text
Forum member supplied image with no explanatory text
Forum member supplied image with no explanatory text
OP
@dorydan avatar
UTC

Member
ET4 150cc 2002
Joined: UTC
Posts: 5
Location: US
 
Member
@dorydan avatar
ET4 150cc 2002
Joined: UTC
Posts: 5
Location: US
UTC quote
Had one part left over after the repair- anybody know what it is? its black plastic and oily.
Forum member supplied image with no explanatory text
@willo avatar
UTC

Hooked
2005 ET4 150
Joined: UTC
Posts: 423
Location: Portland OR
 
Hooked
@willo avatar
2005 ET4 150
Joined: UTC
Posts: 423
Location: Portland OR
UTC quote
Looks like a dust cover/plug
@pinkscooter avatar
UTC

Addicted
GTS 250ie Super, Italjet Velocifero, Scarabeo 150, S50, ET4, ET2
Joined: UTC
Posts: 717
Location: Winston-Salem, NC
 
Addicted
@pinkscooter avatar
GTS 250ie Super, Italjet Velocifero, Scarabeo 150, S50, ET4, ET2
Joined: UTC
Posts: 717
Location: Winston-Salem, NC
UTC quote
That stator looks pretty bad. I had a scoot that did that, it was the crank that had gone bad and caused it to destroy the stator. If the crank is running true it shouldn't do that. I'd make sure the crank is alright before you destroy more.
@motovista avatar
UTC

Veni, Vidi, Posti
GT 200
Joined: UTC
Posts: 9115
Location: Main Street, Watts
 
Veni, Vidi, Posti
@motovista avatar
GT 200
Joined: UTC
Posts: 9115
Location: Main Street, Watts
UTC quote
The first time I pulled a Vespa top end was because the flywheel had come apart. If you've worked on anything else, you don't think about this, because it's something you've never seen or heard of. But just about every time a Leader engine locks up, this is what I check first.
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: 0.0133s ][ Queries: 4 (0.0046s) ][ live ][ 318 ][ ThingOne ]