Modern Vespa

I'm wondering if by watching/listening to this short video clip, can anyone determine whether or not the timing seems okay on my Vespa P200?

Stock motor + BGM Big Box exhaust.

To me it seems high idle...

I am going to venture to say probably not.

Timing seems fine, idle sounds high.

What makes you think the timing is off in the first place?

I concur with the others. Nothing that indicates that your timing is off, but the idle sounds fast and lean.
Here's a very short vid of my idle for comparison.
http://vid52.photobucket.com/albums/g13/GoSlash27/Bodge-a-Palooza/20170212_134335_zps24rtqorp.mp4

Best,
-Slashy

Thanks everyone for the feedback.

Yes, I agree on the idle...it had been very low idle, even with the idle screw tightened all the way down and the mix screw out as much as I could.

I messed with it again after re-cleaning out some carb jets and got it higher, but will need to back it down. It does fluctuate a bit though, and after riding for a while will idle a bit lower than what is in the video.

Was suspicious of the timing because it had been suggested that it might be related to my rare stalling out issue and low idle issue.

I had the stator off to get re-wired, and realized after seeing a before picture that I didn't put it on exactly how it was before.

My stator is the funny one with the horseshoe marking, which I lined up when I put it back on - so no strobe test or anytyhing.

If you all think it sounds fine, I wont worry about it, and will adjust the idle a bit lower.

Scoot109,
To be thorough, you really *should* degree it just to be sure. It's not difficult or expensive, and it can save you a lot of heartache. A retarded ignition timing isn't dangerous, it just makes your bike weak. An over- advanced timing, OTOH, is *very* dangerous. You'll come over a hill and bring back the throttle thinking everything's fine, it'll start pinging and rattling, and then destroy your piston. My advice is to degree it.
The bigger concern is that it sounds lean. Your idle shouldn't wander with temperature. Really, it shouldn't wander at all. You should be able to goose it in neutral and have it return to a steady idle pretty much instantly. Your idle seemed pretty vague by my ear (the gurus will tell you if I'm wrong on this).
A lean condition is potentially hazardous because it makes you run hotter. If you wind up soft- seizing, that's about the best outcome. Shatter a ring (shadooby) and you're looking at serious damage in the bottom end from all the shrapnel.

HTHs,
-Slashy

Ok, I'll prepare to adjust the timing properly - hopefully this coming weekend.

Curious, what makes a couple of you say that the idle seems lean?

I made some more adjustments to the carb, but not sure it sounds much different in this second video. I was able to lower the idle a bit and I loosened the mix screw a bit as well.

As a point of reference, this is a photo showing the stator alignment after I had the stator re-wired. My stator doesn't have the typical line markings I see in most photos; it just has the one line which I lined up with the engine case. I have posted this in another thread before, and pretty sure this is at least close to correct (factory?) setting, which I understand may not be exactly accurate.

My stator in my 1980 P200 is the same way... Yep that looks like it's set on the stock setting.

Scoot109,
I can tell it's lean because the idle is wandering. It's not holding a constant speed. If you can't maintain a nice slow steady idle like I show in my video above, you may have a vacuum leak.

The line on your stator plate really isn't useful for judging the timing, but at least you know your stator is installed the right way.

BRB... gonna take a pic.

Agree with Slashy 100%
A lean idle setting will do exactly what you're describing and make the idle 'hang'. It should be capable of idling pretty low and should return to idle almost immediately after twisting the throttle and letting go.

An air leak somewhere can also cause lean/hanging/wonky idle and can drive you mad trying to tune it!

So here's the shot down my carb. That's really all the space you need for idle; just enough to see the notch in the slide. If you open it past that, your idle mixture screw won't have much effect if any. Idle mixture should be about 1 1/2 turns out from fully closed.

And also (just as an example), here's where my stator sits for proper timing with a p200. As you can see, the lines are in the neighborhood, but not necessarily aligned.



Best,
-Slashy

Slashy, thanks very much for going to the trouble of posting those photos.

I adjusted my idle screw and mix screw, and I have to turn the mix screw out quite a lot - way past the default starting point.

I have attached two photos showing the settings. At the moment, idle is very low but steady, although when I started it up cold this morning it was stalling for a while and bogging when I revved it. Then there was a backfire, but since that, I rode my usual 8 miles to work and the bike is running smoothly, accelerating smoothly, no stalling at stoplights.

Still, I think this indicates I need to look at timing, and quite possibly inside the motor as well(?)

Here is video of idle after the latest adjustments:

Scoot109,
Idle speed is a lot better, but it's still a bit lean as evidenced by your need to open the idle stop a bit wider and backing the mixture screw way out.
If you listen closely, you can also hear the idle speed wandering. I'm afraid you may have a vacuum leak. You should not need to open the mixture screw more than 2 turns. That indicates that either you have a lean/ blocked low speed "idle" jet, or a vacuum leak.

Yes, you should *absolutely* degree your motor and set the timing with a strobe. It won't make a big difference at idle, but it will help you get the best power and efficiency at the top end without grenading.

I find vacuum leaks the old- school way; spray little shots of starting fluid at possible points of leakage while listening for the idle to change.

I'd recommend first setting the timing correctly, then resetting the idle and seeing where that puts you.

Also, I'm concerned about how much it's popping out of the carb. This might also be a result of an over- advanced timing. Hopefully that's all it is.
Congrats on beating the stalling problem! It's coming along nicely

Best,
-Slashy

The later stator plates have two marks, one for 'A' (the old 23 degree setting) and one for 'IT' (the later 18 degree setting). If you are set at stock, then that's probably 23 degrees, which seems too advanced. Try changing to 18/19 by turning the stator clockwise (I think) and see if you are any happier. It's roughly 1mm = 1 degree.

Ok, yesterday I did the following:

1. Installed a new air bellows because mine was starting to crack - this had no effect on things but just needed to be done sooner than later.

2. Checked around the carb for leaks, but did not find anything obvious. Checked the fuel line connections and to make sure it was not pinched (i replaced the fuel line several months ago). Checked the oil line and got it a bit more onto the tube that goes into the carb - don't think this was an issue, but seemed like a good idea.

3. Checked the two sleeve nuts that hold the carb onto the air box. When I re-built the carb last year, I tightened them to the correct torque settings, but I found that they were not very snug yesterday. I tightened both a bit, without over-tightening. I think this may have been part of the problem.

After this, I was able to re-adjust the mixture screw to 1.5 turns out from tight, and I was able to close the throttle gap a bit more with the idle screw, and the bike seemed to idle better.

Not sure if it shows in the video below, but it does sound better - there is more of a "purring" sound now.

Then I took it for a ride and did a plug chop in 3rd gear and have attached photos of the results. Color looks normal, but I do see some deposits. Still, it doesn't look much different than the "normal" one posted on the NGK website.

And I'm still going to adjust the timing, I just need to get a strobe and set aside time, hopefully this weekend, to tackle it.

Get new hardware to hold down the carb - I had this issue and they will continue to re-loosen. I even tried loctite but nothing would keep those suckers at proper torque. To be safe, replace the studs too. Also, consider lapping your carb base on a sheet of glass with some fine wet/dry sandpaper because I also had an issue with this at the same time - carb base was warped. You won't regret these couple fixes.

Scoot109,
Awesome! It sounds like you've got your vacuum leak problem nailed down. The idle sounds a lot better now.
For safety's sake, I recommend keeping the RPMs low in the meantime until you've got the timing set properly.
Congrats,
-Slashy

Thanks Slashy for your help and everyone else for your help and feedback.

Forward progress is a nice motivator!

+1 on sdjohn's suggestions. Also, before you try to set the timing, find top dead center and work from there as the factory timing marks are not always accurate.

^ What Tierney said. The factory timing marks are not *ever* reliable. Degree it, strobe it, and be sure to torque the flywheel down to spec before you start it every time during the process. Don't skimp on that last part or you'll ruin your crankshaft. That's a headache you don't want.

Best,
-Slashy

Found a downloadable, printable degree wheel - I figure I can just mount it to a piece of cardboard and save myself a few bucks.


http://www.laverdafinland.org/cape/kuvat/Degree%20Wheel.jpg

That's what I use! Pop a strong magnet in the center and you've got a bonafide tuning tool ha.

Got my strobe light yesterday, now just need to get a piston stop.

Something I noticed while browsing through my photos - the attached photo was taken before I removed the stator and had it re-wired. From the placement, I can see that I have the timing slightly more retarded from where it was originally, based on the gaps where the screws mount. Wish I had captured a better angle showing the alignment marks on the bottom, but I was not even aware of them yet.

I hooked up my timing light and took a look - the timing marks on the flywheel line up pretty much EXACTLY with the timing marks on the stator when the engine is running and the light is strobing.

I don't think it would be possible or necessary to get them any more aligned. They are not even 2 degrees off and not wandering.

Given the above findings, are you guys suggesting that I still degree it and adjust the timing?

If the results above aren't reliable, how am I supposed to test the timing after I have adjusted by finding TDC and using a degree wheel?

I shot video, but can't see the results from it.

Just want to run this by the forum before I take the next steps. Thanks.

Are you strobing it at idle or revving it up? Since you need to rev to get the degree to move to where it is really going to be. Not at idle..

Mine moves 3-4 degrees it seems from idle to 10-20% throttle and above.

Strobing it at idle.

The scooter shop in SD has great and somewhat funny videos to help you through everything you are struggling with. They are a great resource and close to you!

Plug chop: called a plug chop because you must cut a brand new (ridden only at the throttle setting and motor loading being investigated) and look at the base of the insulator. Try Google.

Timing: other than an air leak, the most critical item that will blow a 2 stroke engine. I am not sure what you are strobing between flywheel and stator.... But, find tdc, mark off the desired timing with the degree wheel, and then strobe and adjust. Again, lots of great videos out there.

And FYI, not all forum (or Internet) advice is equal. Always double check! YouTube is a good reference because videos with bad info get commented on...

Scoot109,
Everything that TR said.

The marks between the flywheel and stator aren't useful references, so having them line up when strobed doesn't mean anything.

Check the first 8 minutes of this video. Ignore the rest, as it's instructions for a points ignition.

Once you have your timing marks placed, you need to strobe it to see where they line up.
Adjusting the timing on yours means pulling the flywheel, moving the stator, and reinstalling the flywheel. You may need to do this several times to get it right. Be sure to torque your flywheel to spec every time before starting it during this process. Failure to do so can damage your crankshaft keyway.

Best,
-Slashy

Thanks, I think I understand now...I'm creating a new reference point by degreeing it myself.

I do that every time I fit or remove a carb. These aluminum units warp very easily, and lapping them for safety on flat glass (I use part of a 1 inch thick marble mantle found in the street) makes sure your carb is installed properly (in that respect, at least).

re: carb - Yes, I did check for warping and gave the base a light sanding when I rebuilt it last year.

I checked the two mounting bolts the other day, since re-torquing them, and they have not loosened, so I think I just did not torque them down quite enough after the rebuild.

I have re-watched the Scooterwest video and the SIP video and done my markings.

After my calculations I ended up with a number of 35 degrees.

Once the bike warmed up, at idle my IT mark on the flywheel was a few degrees forward (clockwise) of the mark on the case. When I revved the engine for a bit, the timing mark moved back slightly closer to the mark on the case.

I have just removed the flywheel, adjusted the stator plate CCW slightly, and am now re-fitting/torquing the flywheel before taking another reading. I think this is going to set it back at what it was prior to my original removal when I had the stator re-wired.

More to come....

After my timing adjustment, my IT mark on the flywheel is lining up pretty much spot on with the case marking, both at idle and when revving.

I torqued the flywheel nut to about 43 foot pounds.

Also, those factory flywheel marking lines are aligned pretty well with the markings on the stator, visible through the "beanhole".

I re-adjusted the idle screw and mix screw as well. Mix screw is about 1.5 turns out from tight, and idle screw is about that as well, although I have read that the "default" setting is normally 2.5 turns out.
To make these adjustments, I tightened the idle screw all the way (engine raced) then tightened the mix screw all the way, then loosened the mix screw in half turn increments until the idle stopped changing, which was a bit over 1.5 turns. Then I turned the idle down with the idle screw until it seemed about right (comparing to Slashy's video).

Latest video below:

Sounds pretty good! Never heard of a "default" setting for the idle screw, though. And I'm not sure about the procedure followed to set the mix screw. I generally:
1. tighten the idle screw so that idle is slightly too high (to keep it from stalling)
2. screw the mix screw fully in
3. unscrew the mix screw until idle is at its highest (go past highest point, then back, to fine tune it)
4. screw it back in, this time counting the rotations, and write down n° of rotations for future reference (should be within the 2 full rotations limit, otherwise the corresponding jet is wrong)
5. unscrew again according to the noted n° of rotations, and make sure the setting is still right (otherwise start again from 2.)
6. Lower the idle with the idle screw, back to a workable level. You're done. The engine should rev fast, and go back down rather quickly when letting go of the throttle.

Scoot,
That sounds 1000 times better! Way to go!!

Idle's wandering a bit; you may want to richen it up a little. Other than that, I think you're good to go now. FWIW, my procedure is very similar to Frank N. Stein's. 1 1/2 out on the mixture and enough throttle to keep it idling. Then adjust mixture for highest idle, while reducing the idle stop to keep it from racing.
Once that point is achieved, turn it rich until you notice a slight drop in idle and reset your idle speed. As he said, you should have a low steady idle and it should return quickly after revving.


Congrats,
-Slashy

it has been satisfying reading about your progress

Thanks to everyone who offered assistance here! The input from those with your experience is invaluable.

I'm pretty confident the idle settings and timing are sorted out now. The bike is running as good as ever, with smooth acceleration.

The only slight issue I have at the moment is when the bike is cold, like sitting overnight, it starts on third kick with choke out, but after I push the choke back in it stalls after a few seconds. Then it will start again on the next kick.

This happens several times before it will idle without stalling. Then I'm on my way and no stalling during my 8 mile commute with quite a few traffic stops en route.

Yesterday I left it idling for at least 10 minutes on the driveway after it was warmed up and no issues.

Glad you got it dialed...

Go ahead and leave the choke partly out until you have ridden a block or two...

Maybe gice the mix screw another quarter turn richer...