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Subject: "Somebody help! I want to ride my Vespa!" Archived thread - Read only
 
 
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Reading Topic #43843

vespatude
Member since Dec-12-05
90 posts
Dec-12-05, 10:34 AM (EDT)
 
"Somebody help! I want to ride my Vespa!"
 
   I purchased a restored 64 Vespa 150. Turns out that the body is in excellent condition, but the engine had its issues. I have now completely rebuilt the engine. All four gears have been replaced and the new needle bearings have bee put in (they were binding on the piston pinion). Everything checks out and no parts were left over after putting the case back together.

So, why am I having problems? Here is what happened on my maiden voyage:

The engine started up on the fourth kick. I let it idle at a low rev for a little bit. I then shut it down. I started it up again - it started on the second kick. I played around a little with the idle speed and then took it out on the road. After riding for about five minutes (I went through all the gears, but did not push the scoot), the engine started leveling off and no matter how much I boosted the throttle, it stayed at that constant RPM. Finally, I got a backfire and the engine kept bogging until I got it home.

Now, I can't get it to run for any length of time. I get spark and the engine will even turn over on occasion, but it won't run for long and it will not rev beyond a certain low RPM.

Timing? Carb issue?

Help!

I got a new vespatude.
http://www.vespatude.com


 

 
Laramy
Member since May-12-04
154 posts
Dec-12-05, 10:40 AM (EDT)
 
1. "RE: Somebody help! I want to ride my Vespa!"
In response to message #0
 
   Sounds like timing to me, what kind of ignition do you have?


 
vespatude
Member since Dec-12-05
90 posts
Dec-12-05, 11:13 AM (EDT)
 
2. "RE: Somebody help! I want to ride my Vespa!"
In response to message #1
 
   It is not electronic. The bike was upgraded to a 12 volt stator system before I got it. I replaced the wiring harness, but have the regulator that was on the bike when I got it. I also put the stator back in the same position it was in when I got the bike.

If it is timing, how come it rode so well for the first five minutes? It has me confused. Is it possible I have flooded the bottom-end with fuel? When I take the carb cover off, it sounds like a drowning man gasping for air.

I got a new vespatude.
http://www.vespatude.com


 
cphilip
Member since Jul-16-03
7408 posts
Dec-12-05, 11:56 AM (EDT)
 
3. "RE: Somebody help! I want to ride my Vespa!"
In response to message #2
 
   Try a new coil. Coils have been well known to run fine when cold and then act up sporadicaly after getting hot. Also... suspect a partialy clogged exhaust.


 
vespatude
Member since Dec-12-05
90 posts
Dec-12-05, 01:55 PM (EDT)
 
5. "RE: Somebody help! I want to ride my Vespa!"
In response to message #3
 
   I wondered about that as a possibility. Also, the clogged exhaust is a VERY good possibility. Before I did the rebuild, it used to backfire something awful. One time it actually blew a hole in the muffler! I had it welded shut and put it back on. You might have a point on that one

I got a new vespatude.
http://www.vespatude.com


 
Laramy
Member since May-12-04
154 posts
Dec-12-05, 11:56 AM (EDT)
 
4. "RE: Somebody help! I want to ride my Vespa!"
In response to message #2
 
   You may be beyond my skills here, so take what I say as a suggestion and with a very large grain of salt. Having said that, I take it that the bike worked okay at low RPM's for a while - what would you say, about 25% throttle or so? I think the main jet handles the first 25% of throttle so maybe that was okay but the carb may not be dialed in properly beyond that. Is it the stock carb?

As for the timing, the stator may have slipped or worse yet the woodruff key may have sheered. Did you tighten everything down properly? I didn't on my first and only rebuild (heck, I made just about every rookie mistake in the book) and sheered the woodruff key the first time I throttled up. I was lucky and it wasn't a bad replacement job, but I've heard horror stories so your mileage may vary. Good luck.


 
vespatude
Member since Dec-12-05
90 posts
Dec-12-05, 01:59 PM (EDT)
 
6. "RE: Somebody help! I want to ride my Vespa!"
In response to message #4
 
   I was scared out of my mind going in there to rebuild, so I was extra careful. Everything was accounted for a buttoned down just fine. I also had an experienced engine rebuilder look it over. He signed off on it.

Here is an update. If I start the bike with the choke all the way out with no throttle, it will start up on the first kick. I can then push the throttle in and it will idle low for a few seconds and then it will begin to increase in RPMs until it finally sounds like it is drowning. If I happen to touch the throttle at any point during the idle, it dies immediately.

Get this, I can start it without the fuel valve open. Makes me think there is a lot of gas in there somewhere...

I got a new vespatude.
http://www.vespatude.com


 
cphilip
Member since Jul-16-03
7408 posts
Dec-12-05, 02:41 PM (EDT)
 
8. "RE: Somebody help! I want to ride my Vespa!"
In response to message #6
 
   The backfiring is typical of a poor spark. Suspect something there for that

The increase RPM with choke in makes one think of air leak. Recheck Carb to box gasket and Carb Box to Engine gasket first off. Then recheck Head torque and work back from there.

Good point about that fuel line. Also remember that there is enough fuel left in the line and float bowl to start the scooter and run for oh... sometimes as much as five minutes at Idle. 5/16 time 24" plus fuel bowl is a good bit of fuel at idle.


 
vespatude
Member since Dec-12-05
90 posts
Dec-12-05, 04:18 PM (EDT)
 
16. "RE: Somebody help! I want to ride my Vespa!"
In response to message #8
 
   Thanks, once I replace the fuel line I will work through the carb check points you mention.

I got a new vespatude.
http://www.vespatude.com


 
decadron
Member since Nov-25-02
1734 posts
Dec-12-05, 02:08 PM (EDT)
 
7. "RE: Somebody help! I want to ride my Vespa!"
In response to message #0
 
   this is gunna sound ridiculously simple buuut....

check to insure your fuel line is not too long - a very common problem .

Your tank should not be able to lift all the way outta the frame if the line ain't toooooo looooonnnnggggg.

a too-long line will cause the bike to run out of gas over and over again - then start and act normal - then run outta gas again.

jes' a guess


No Chinese Junk


 
vespatude
Member since Dec-12-05
90 posts
Dec-12-05, 03:02 PM (EDT)
 
9. "RE: Somebody help! I want to ride my Vespa!"
In response to message #7
 
   I think you are the winner! I was talking to a local Vespa guy today at lunch explaining the problem. He has seen the bike before and he said, "You might want to look at that fuel line. It isn't a real fuel line but some sort of white rubber stuff." It is, it is also very pliable.

Rather than the fuel line being too long, the problem is that it is too short and I had to stretch it to attack to the carb. I believe this may have made the pliable rubber constrict from an O to a 0. As the carb pulls more on the gas, it may be suctioning the line closed. That would be why it starts fine with fuel sitting in the carb, but as it burns off and the line has a vacuum placed on it it begins to run lean and then finally dies.

I'll test it tonight by installing an actual 2' long 1/4" ID fuel line. I'll let you know what happens.

I got a new vespatude.
http://www.vespatude.com


 
AirborneVespa
unregistered user
Dec-12-05, 03:03 PM (EDT)
 
10. "RE: Somebody help! I want to ride my Vespa!"
In response to message #7
 
   The fuel line, if you do check it, should be 24"


 
vespatude
Member since Dec-12-05
90 posts
Dec-12-05, 03:38 PM (EDT)
 
11. "RE: Somebody help! I want to ride my Vespa!"
In response to message #10
 
   Yep. I have purchased a 24" (2') quarter-inch fuel line. I will definitely be pulling the tank tonight and replacing the piece of garbage that is there. I'll post some pics of the process on my site http://www.vespatude.com

I got a new vespatude.
http://www.vespatude.com


 
invespa
Member since Feb-7-04
265 posts
Dec-12-05, 03:42 PM (EDT)
 
12. "RE: Somebody help! I want to ride my Vespa!"
In response to message #10
 
   I had those symptoms you described.Check ALL these things (after you sort the hose)
Pull off the carb,strip it and clean it with compressed air
Put a new gasket under the carb box(with grease on the gasket)
Put a new carb to engine gasket (with grease)
Mark top dead centre and 22 degrees(????) before on the flywheel with paint and verify timing (or move the stator methodically 2 degrees at a time)
Check the choke cable isnt loose and that the "outer cable" is housed in the carb nicely
Check that that the accelerator cable is not too tight or loose at the carb end

It will be the timing...and the air fuel mix

Do the timing first or all your air fuel adjustments will be crap

You're nearly there.Perserverence

shane o


 
vespatude
Member since Dec-12-05
90 posts
Dec-12-05, 04:22 PM (EDT)
 
17. "RE: Somebody help! I want to ride my Vespa!"
In response to message #12
 
   >I had those symptoms you described.Check ALL these things
>(after you sort the hose)
>Pull off the carb,strip it and clean it with compressed air

I did this. It is clean as a whistle.

>Put a new gasket under the carb box(with grease on the
>gasket)

It has a new gasket - though I admit I did not put grease on it.

>Put a new carb to engine gasket (with grease)

Same as above.

>Mark top dead centre and 22 degrees(????) before on the
>flywheel with paint and verify timing (or move the stator
>methodically 2 degrees at a time)

This I was hoping not to have to do Though that will be my next step once I get the fuel issues cleared up.

>Check the choke cable isnt loose and that the "outer cable"
>is housed in the carb nicely

This checks out okay.

>Check that that the accelerator cable is not too tight or
>loose at the carb end

This also checks out okay.

>
>It will be the timing...and the air fuel mix
>
>Do the timing first or all your air fuel adjustments will be
>crap
>

You are probably right. I know I am going to have to do the timing deal at some point here.

>You're nearly there.Perserverence

Keep telling me that!

I got a new vespatude.
http://www.vespatude.com


 
e
Member since Jun-3-02
7493 posts
Dec-12-05, 03:49 PM (EDT)
 
13. "RE: Somebody help! I want to ride my Vespa!"
In response to message #0
 
   LAST EDITED ON Dec-12-05 AT 03:51 PM (EDT)
 
From looking at your blog, you already know you've bought an Indonsian restored Vespa, and it sounds like you were prewarned about subpar quality bikes coming from that part of the world. As you may already be discovering, it probably isn't as advertised. You had to rebuild the motor right away, fortunatly it looks like you were lucky and got something that was rebuildable. Many aren't salvagable at all. Hopefully you guys inspected everything inside and outside the motor carefully before reassembling.

You're discovering the fuel line is another corner they cut, I'd recomend having someone that knows VBB's give the front fork a good look over too.
cover all your bases. You'll probably discover more cut corners as time goes on, make sure there aren't any that can endanger your life before you start riding it all over the place.


 
vespatude
Member since Dec-12-05
90 posts
Dec-12-05, 04:10 PM (EDT)
 
14. "RE: Somebody help! I want to ride my Vespa!"
In response to message #13
 
   Did that. Sure the Indonesian way was scary, but it is an actual Italian Vespa - the VIN is proof of that. I feel very comfortable with the scooter now. I have taken the thing completely apart -- I mean completely! I can basically say I rebuilt the entire thing. So, I know the condition of every part.

You are correct. They cut a lot of corners. It was stupid to have bought the bike that way, but now that I have it -- I love it! Other than these few odds and ends left, I have met each corner and ironed it out. For instance, the wiring was a mess! I had to rebuild the harness.

Sorry for taking it a little personal, but even though the baby might be ugly -- It is still my baby

I got a new vespatude.
http://www.vespatude.com


 
m5
Member since Jun-7-02
1291 posts
Dec-12-05, 04:15 PM (EDT)
 
15. "RE: Somebody help! I want to ride my Vespa!"
In response to message #14
 
   So is it a Super engine in an older body with 10" wheels?

-Matt
2StrokeBuzz/PrimoPartsRacing


 
vespatude
Member since Dec-12-05
90 posts
Dec-12-05, 04:28 PM (EDT)
 
18. "RE: Somebody help! I want to ride my Vespa!"
In response to message #15
 
   LAST EDITED ON Dec-12-05 AT 04:31 PM (EDT)
 
>So is it a Super engine in an older body with 10" wheels?

No, actually, it isn't a Super at all. I haven't made that change to my Web site. I thought it was a Super (due to the pictures I was sent by my Indonesian friend - don't rub it in!), but turns out it is a Vespa 150 four-speed. The body and engine VINs match the original title. So, the body and engine are original. Yes, it does have a 10 inch wheel conversion. I don't have a problem with that -- it is something I would have done had it come as an 8 inch.

I really like the bike. The body really is as advertised and the sidecar is great (though I won't be hooking that up again until I have had time to run in the engine). Other than the engine and the wiring, I have been very happy with the scooter.

Down the road, I would like to go with a 177 conversion kit -- or even go up to a 200cc engine replacement. That would work better with the sidecar on it. All that is down the road aways. Right now, I just want to ride, period.

I got a new vespatude.
http://www.vespatude.com


 
mrchristopher
Member since Dec-7-04
25 posts
Dec-16-05, 00:32 AM (EDT)
 
28. "RE: Somebody help! I want to ride my Vespa!"
In response to message #14
 
   i don't have any first-hand experience with asian restorations and i've only been riding myself for barely a couple years so i'm still a newbie, but... it sounds like the one other thing you might want to check is the frame itself. it's good that you're fixing all the mechanical problems but have you checked to make sure the metal underneath the new paint is solid? i've heard of all kinds of crazy body damage being covered up by new paint, even two different scooters being welded together. given the other issues you've run into, it's something to think about. that said, i hope you get your scooter up and running asap and can start enjoying it...


 
vespatude
Member since Dec-12-05
90 posts
Dec-16-05, 11:13 AM (EDT)
 
29. "RE: Somebody help! I want to ride my Vespa!"
In response to message #28
 
   I have checked the frame. I did this by looking under it for any creases beneath the paint as well as inside the frame. I looked inside as well as ran my hand up into the frame by the floorboard. No rust and things are solid.

The reason I think the scooter ended up getting restored and sold is that the engine at one time came apart. You can see the scars from where bearings or whatever came loose in the top end. Plus, it looks like the metal around the oil drain plug was broken out. It was welded back in place and they actually did a pretty good job on that.

So, as much as people want to trash on my "Asian Restoration," the scoot checks out and when I am done with it, I'll put it up against any other scoot out there. It is Italian - it just had to take a long detour over the last 41 years to get to me.

Thanks for the empathy. I hope I get it up and running soon as well.

I got a new vespatude.
http://www.vespatude.com


 
Sluggo
Member since Jan-9-03
424 posts
Dec-12-05, 04:56 PM (EDT)
 
19. "RE: Somebody help! I want to ride my Vespa!"
In response to message #0
 
   Any problems with the red engine paint? I've never seen an engine painted like that, its taking a bit to let it sink in that you have a bright red engine.

Importing Italy, one part at a time.

78' P200E
75' TS 125
63' TV 175


 
vespatude
Member since Dec-12-05
90 posts
Dec-12-05, 05:05 PM (EDT)
 
20. "RE: Somebody help! I want to ride my Vespa!"
In response to message #19
 
   No, no problems with the paint -- other than Vespa purists laughing at me. The paint is only on the exterior of the engine and not on any of the gasket fitted areas.

I guess it comes from my old redneck V8 block days. Your engine wasn't done until it was bright red

My guess is that the paint will last several months and then will begin to wear away. No big deal, I keep the cowling on -- but it will be easy to find oil.

I got a new vespatude.
http://www.vespatude.com


 
pavlo
Member since Aug-4-02
216 posts
Dec-12-05, 08:47 PM (EDT)
 
21. "RE: Somebody help! I want to ride my Vespa!"
In response to message #0
 
   I think I have read thru everything that's been posted. and shame on y'all.

No one said to check and see if your piston is upside-down. You said you did the rebuild yourself, right? A bike will often run really crappy like with no other explanation but an upside down piston screwing up all your porting - it often sounds like the prob you are describing and is a common problem even though no one ever wants to admit doing it.

Second - the first thing I have learned to check on any poorly running bike after the sparkplug is the compression. Go out and buy a compression tester. Then test the compression. If it is less than 100psi or so, you are screwed and that is your problem. Go out and buy new rings and/or piston.


pavlo
denver jksc


 
cphilip
Member since Jul-16-03
7408 posts
Dec-12-05, 08:57 PM (EDT)
 
22. "RE: Somebody help! I want to ride my Vespa!"
In response to message #21
 
   LAST EDITED ON Dec-12-05 AT 09:03 PM (EDT)
 
>I think I have read thru everything that's been posted. and
>shame on y'all.
>
>No one said to check and see if your piston is upside-down.

Your right Pavlo. That should have been on our list of things to check. But because he claimed it ran fine for five minutes most of us dismissed that. It should not have run right at all if that was the case. But its something to double check.

Also... the correct diameter for that fuel line is 5/16. Thats the inside diameter of it. 24" long is correct.


 
Jumbo
unregistered user
Dec-12-05, 09:14 PM (EDT)
 
23. "RE: Somebody help! I want to ride my Vespa!"
In response to message #22
 
   Yes 5/16 or you'll have the same problem again...


 
vespatude
Member since Dec-12-05
90 posts
Dec-12-05, 09:22 PM (EDT)
 
24. "RE: Somebody help! I want to ride my Vespa!"
In response to message #21
 
   Compression is fine. The piston is correct. The head of the piston has a little arrow on it that tells you which way is down. Plus, I double checked to make sure the ports were lined up.

Actually, I think I have found the problem. It is fuel related.

I got a new vespatude.
http://www.vespatude.com


 
vespatude
Member since Dec-12-05
90 posts
Dec-12-05, 09:32 PM (EDT)
 
25. "RE: Somebody help! I want to ride my Vespa!"
In response to message #0
 
   Well, I think I have it figured out. You can see the entire episode here at my blog, vespatude.com: Maybe I'll change the scoot's name to delay.

The bottom line is a bad fuel tap -- plus, I think, a crappy fuel line. The fuel filter and fuel tap tube came off inside the tank. So, the fuel running into the carb when the scoot wasn't running (because the valve was not shutting off) flooded the bike. Then when it was running, the gunk would settle in the valve and starve the carb. A weird mix of feast and famine.

Once I can get my parts and put it all back together, I'll let you know.

I got a new vespatude.
http://www.vespatude.com


 
vespatude
Member since Dec-12-05
90 posts
Dec-15-05, 10:31 AM (EDT)
 
26. "Latest Update on this issue"
In response to message #0
 
   The fuel tap and fuel line has been replaced. Got a good flow of fuel with the tap open and complete shut off with it closed. So, that problem is now behind me. However, the same issues exists. Here is a full report.

I have now removed the carb and am going to go in and make sure the gunk that was in the fuel tap isn't also clogging the ports of the carb. If after that I still have the same issues, I will go on to the timing.

I got a new vespatude.
http://www.vespatude.com


 
Laramy
Member since May-12-04
154 posts
Dec-15-05, 10:42 AM (EDT)
 
27. "RE: Latest Update on this issue"
In response to message #26
 
   You said on your blog that when you put the choke in, the idle stays for a few seconds then rpms go up and it dies out. Sounds like an air leak somewhere to me. Check your seals, sometimes even new ones get pinched or something that will leave a little gap. That happened to me when I put a new crank in the motor that didn't match the VBB seal, had to get a new seal of the right size. Good luck.


 

 

 






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