Modern Vespa

The history if you are curious. Digging into the oily scoot to see what is going on

So it took me half the day but I got the engine out. Hardest part was the exhaust even with the 1/4 inch wobble extensions. What a PITA. Tempted to drill some access holes right through the frame.

Anyway after I disconnected all of the rear stuff I put the rear wheel back on to make it easier to move plus I can set it on to center stand to work. Just hosed it off and going to clean it up a little more then start on the top end.

Oh there was one thing that was connected to the engine that the service manual that I got from jimc's site doesn't mention for disconnect. I had to grab a knife and slice it. What do you think it was?

On the top end. The manual is a bit confusing. I know I have to remove the timing chain and sprocket but is there any reason I need to remove the cam shaft to get the head off? I mean I might do it later to check for wear but it doesn't look like it is a have to.

You don't have to take the camshaft from a typical automotive head in order to remove the whole head.

Looking at the parts diagram, it seems once you have the timing chain bits off you can remove the head.

Yeah that is what I was thinking to. The arrangement of the manual had me a little confused though.

It's like watching a surgery from the observation gallery!

--- "We can rebuild him, we have the technology...." ---Oscar Goldman

Following your Project...

Keith
Marietta, GA

The bionic scoot.

If I am not too tired tonight I will start on the top end. My lower back is sore from yesterdays fun.

Kinda Looks like the New MP1/500 Uni-Cycle with the ABS Off.

Keith

Yeah just need a seat, tank, radiator and silencer.

OK since no one has answered it. The hose that did not show up in the service manual as something to detach is the return hose for the evap canister where it connects to the throttle body. Only a note for American riders to add to the checklist if you ever have to drop your engine. Which I sincerely hope you don't.

Oh wow, Sticky...so sorry I didn't see this earlier. It's actually cool that you're digging in deep...interesting to follow. I'll be dropping out my back end eventually for gaskets/tune up stuff and have some mechs go through it to bring her back a few years.

Anyways, I am by no means a gearhead or expert...but I gotta say, your experience sounds EXACTLY like my 500 before she died

She would stall/sputter and was always leaking oil despite filling her up but once it got low she would hold that oil for awhile. Finally had the "oil splatter" incident where everything jettison out the back end and I was able to barely nurse her home. About 2 weeks later...dead. She would try initially to turn over then nothing. When I took her into a good shop, they gave me the bad news - engine needed to be basically rebuilt -3-4 grand.

God, I hope you don't have what she had, but it sounds virtually identical right down to the description you gave of where the oil sprayed all up on the hugger and around. Good luck bro.

Thanks for that info Shawn. Fingers crossed.

ow btw iff you only want to change the cylinder and piston there was no need to drop the whole engine when you take of all the tubberware

you could also jack the frame up and take the shocks off then it will tilt

Yeah OAD mentioned about doing similar. I figured though that since it was my first time doing it and that I don't really know what to expect it would be easier for me to have as clear a picture as possible.

With the engine out does anyone have any thoughts on what else I might check since it will be much easier.

Not sure what it is called?

I wonder since you have the engine out, it would make sense to replace the Bushings/Shaft that holds the engine in place. I recently seen a Scooter West Video of them doing another bike, where the bushing wear will cause the whole engine to wobble so slightly and cause other problems. If I had mine out, I would check this for wear and see if makes sense to change?

Keith

The rubberbushing don't need replacing its the bearing behind it HK6303 or 6304

Sticky now you can polish the engine like i did

I don't have the time or patience to do that Maksor. I did spray it down with Gunk and rinse it to get most of the crap off but that is as far as I go.

Thanks to you and klaborde for the tip on the bearings. I will check them.

If and when I get back to FLA, I will ride over and set on a stool, drink beer, and give free advice. I will bring friends to help.

Sounds good. I like Guinness.

Hi Sticky, great work you are doing to solve the engine problem. Hopefully you will be back on the road by the Spring Gathering and we can finish the ride up.

You thinkin' about putting it up on a bench moving forward? And saving that back?

OK got the head off tonight and the news isn't good. Looks like a chunk blew out of the edge of the piston. There is also a worn area on the side of the head where it blew. The surfaces of the top, valves and piston are rough will know more when I have time to clean. Anyway, looks like I will be looking up parts.

What I am baffled by is how does this happen. Manufacturing defect? I am comfident that I followed all required maintenance intervals. Comments welcome.

ouch ,OUCH. your going to need a new cyl , piston, rings maybe head depends on if it can be cleaned up, hard to tell with out seeing it in person. but its possible.

edit. cylinder with piston kit not too bad of price $302 from AF! # 873812

Yeah ouch is right. Well at least the mystery of the ever increasing amounts of oil in the airbox is solved. I found this on ebay. Numbers are different but the it says BV 500. Same engine right. http://www.ebay.com/itm/Piaggio-X9-BV-500-Evolution-Aprilia-Scarabeo-Atlantic-500-Piston-Kit-8302360004/321696522584?_trksid=p2047675.c100011.m1850&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20140602152332%26meid%3Db120f302528941ffa7b4b4075a2578ff%26pid%3D100011%26rk%3D3%26rkt%3D10%26sd%3D361203244103

Sorry to have been right...this was the death of KITT as well. At least you have the ability to work on it and do something about it...I was at the mercy of $80/hr labor charges!

Hey, why are you stealing my photos from my engine breakdown:



I paid $1400 to get the engine dropped, rebuilt from the ground up, and reinstalled. It included a new piston and rings, pin, cylinder, head (cheaper to buy an entire head as compared to a rebuild), and the associated gaskets and fluids.

Looking at the piston, I'm positive it's a weak ring landing that cracks, flakes off, and melts down - taking everything with it. And it's quite common...

On the plus side, I'm at 3K miles since the rebuild, and I've collected about 5cc of oil in the oil-air separator I installed on the PCV system. Prior, I was running 30cc every fillup. So the oil consumption is now gone.

My wife said "Whatcha doin' today?"
I said "Nothing."
She said "You did that yesterday."
I said "I wasn't finished."

Not a mechanic, but is it possible some of the missing bits of the piston / ring could have ended up in the bowels of the engine? If so, would you just flush it out?

Commiserations this is certainly very bad luck. My guess would be that the cylinder wall damage is a clue to where the problem started. It could all arise from running in without ever letting the engine rev freely, leaving a ridge which damage the ring when high rpm were used. Other possible causes would be a defect in the cylinder wall from new or some local corrosion caused perhaps by the engine not being run up to normal temperature followed by a long period without use.

OMG...

Sticky what's the plan... Scrap for Parts, and get one of the New MP3/500's later this year?

Keith
Marietta, GA

Hang in there Sticky looks like you found the problem ..hope you can repair
it. We're watching and hoping things turn out for the best.
I'm good for fluid changes and turn signal replacements but not the sort of thing that you are taking on. You're more of a mechanic that you give in to be

Sticky the Beverly evo cylinderkit won't fit its a 460cc not a 492.7cc

The 460 does have a differtent stroke and is smaller

And only a piston wont work you cylinder is also scratched better go for the option that OAD suggested complet kit Cylinder piston and rings

Besides, you have to allow two days a week for practice.

Thank you for sharing your interesting project with us.

The mpe manual calls for 91 octane gas/petrol be used. Have you been using a lower octane?

Dan yours looks like it was even more catastrophic. Thanks for the link. I will be checking the valve seats and valves.

roadster thanks for that analysis. I do think though that it may be a manufacturing defect since there have been a couple other 2008's that this has happened to.

klaborde nope gonna rebuild.

Thanks Maksor. I had a feeling it would not be that cheap.


jfolander I ran 93 for most of that engine's life but switched to ethanol free 90 about a year ago.

I just play one on tv. If I can get it back together and running maybe I will get a junior mechanic merit badge.

It's like déjà Vu. Mine was just under warranty when it happened to me on the way to OAD. 34k miles later I'm still rolling on.

I am 100% convinced this is from a failed piston land. Crack that, lose a chunk, and little pieces running around will cause all kinds of nightmares.

Also causes all the piston scoring and the damage to the head and valves. Replace them, don't try to repair them. You're going to have to machine off a few mm to get the cylinder head face flat and polished, but that will really eat into your valve clearance and adjustments. Just plan on a new head assembly.

It also explains why it's just the 2008s that have this problem. A bad run of forgings with incorrect settings on cooling (or forging pressure) would create weak steel on the outside, right where you machine the landings for the rings, making it very susceptible to breaking.

And it also explains why you get a lot more blowby and oil out of the engine - each detonation sends a nice big pulse of pressure into the crankcase and out the whole system. Blowing oil is a sign of excess blowby - and cracked landings will do that VERY well.

I'm not an automotive engineer - but have spent decades doing forgings, machining processes, working with coatings and materials and plastics in other industries. I'm sure it's a bad batch of pistons from the 2008 run. It explains the oil consumption, the damage to the pistons, the damage to the head and cylinder, and the consistent failures seen (there were other photos here from another member with his cracked/missing piston ring lands).

A batch of failed forgings would explain it.

On the plus side, the parts to repair the damage (full head assembly, piston, pin, cylinder) aren't TOO expensive. I was able to get all the parts and full labor (drop the bike off, pick it up 8 weeks later - after waiting for a few parts to ship from Italy) for around $1400. So it's not a "death blow" in terms of cost - but it's still a cost.

And another plus is my oil consumption is TOTALLY gone, the engine runs fine and smooth, and I find that my RPMs are lower at higher speed. Just before she melted down, I was doing 7500 RPM to go an indicated 73-75 MPH. Now that RPM would push close to an indicated 90 MPH. More HP (less blowby) means lower gearing from the CVT.

Yep, it could. Drop the oil pan and drain/clean everything. If the crank still spins free, then the bearings aren't really affected.