Modern Vespa

Does anyone have experience using an iridium spark plug (CR8EIX or CR8EIB) in a 2015 (or later) GTS 300? I just installed one, but the bike won't start; the starting issue might be a weak battery, though. Does this plug work on the later GTS 300s (mine is a 2015)?

I'm interested in any experience with this too. When I bought a spare plug from my dealer they sold me a CR8EIX for NZ$35 (!). However, I can't find anywhere where Piaggio sanctions this type of plug, so I haven't used it yet.

Nothing wrong with Iridium but the price, it will last a lot longer. Double or triple your change interval.
Do your own cross ref on NGK website if you are in doubt. OEM plug number is in your manual.

I hope you really like your dealer. In the US that plug costs about $10 ($15 nzd)

No, I don't like the dealer, partly because all their charges are exhorbitant. I bought the Haynes manual and get my parts from ScooterWest now. I am doing everything myself. The combination of a 600-odd km round trip to reach the dealer, getting charged too much for everything, and dodgy quality of service was not sufficiently attractive to make me go back after the first service. Very short-sighted of them!

theschuman, irridium is fine and as said, it's lasts so much longer. When you try to start your bike, what happens? Does the motor crank when you push the button but is just not starting? If it was running before you changed the plug, it should run now unless you have not fitted the spark plug cap correctly or the battery has mysteriously discharged overnight or something.

The motor cranks and cranks as long as I hold the starting button until the battery drains. I replaced the battery yesterday and, perhaps stupidly, replaced the spark plug at the same time with the CR8EIX... Same deal, lots of cranking, no starting. Just for good measure (really out of sheer ignorance and inability to find a CR8EKB), I tried an E3.38 plug:

https://e3sparkplugs.com/parts/?part=E3.38&cr=1

I have spark across the plug (visually), but no starting. Thoughts?

I'd suspect that the spark plug cap isn't seated correctly, or that the wire broke when you changed the plug. Do you get spark?

Oh, never mind. I see you have spark.

Could you put the old plug back in?

Have you ruled out a fuel issue?

The fuel pump goes on when the ignition is turned on and I smell fuel, but is there a way to test fuel delivery?

Step 1) Make sure you have spark, no need to guess. Pull the plug cap off, plug it into another plug and lay it on the motor so it gets ground. Then crank motor while looking at the plug. Do this in a dark area, not out in the sun light.
Do you get spark?
If yes, then go to step 2, check if you are getting fuel.
If no you need to find out why.

Step 2) To test if you are lacking fuel, pull off the hose going to the throttle body and give it a good shoot of starting fluid.
Do it start?
If yes, you aren't getting fuel. Test injector and fuel pump.
If no you need to check compression.

Is the new plug correctly seated, or (gulp) possibly cross threaded?

As far as I know, the plug is seated correctly... I even used a torque wrench to set it to 9.5 ft.lbs.

1.) I definitely have spark... I checked that yesterday. I even replaced the spark plug with the OEM CR8EKB today. Same deal - it still just cranks and cranks.

2.) I don't have starting fluid, but I'll get some. Where is the throttle body?

You can just pull the air filter cover off, remove the foam filter and spray it in the black hose/tube at the top of the air cleaner going to the throttle body. Now you'll know where the throttle body is too, it is at the end of the black hose/tube.
Crank it a few times, if it starts for a few seconds you have a fuel delivery problem.

I would do a 2 count of the spray the first time, then a little longer if it doesn't start the first time.

Just for the purpose of informing others: you can buy the correct NGK new on ebay with free shipping for under $7 each. Seems like I paid ~ $6.78

Good tip...I can locate the air filter! It will also allow me to check the filter while I'm at it - it should be fine, as it was replaced in May at 6300 miles, but you never know. Perhaps I'll tackle this tomorrow after work. Thanks.

I tried the starter fluid, both in the air filter (where it just kind of poured out onto the garage floor) and more directly where the air feeds into the throttle body (?) by removing the hose. It did not start either way (it turned over as before).

Then, I think I found where the fuel hose leads into the throttle body. It had little white tabs, so I removed it (see photo). With it removed, I turned the ignition to run the fuel pump... Lots of gasoline (more than an ounce per second) came out - luckily I had a bottle ready to catch it. Is the fuel pump supposed to push out that much gas? I put the hose back on... It's not really a hose, but some plastic thingy with white tabs (I believe plastic thingy is the technical term). Anyway, once I re-assembled, I tried to start it again... Same deal - lots of turning over and no starting.

One poster said maybe my spark plug was cross-threaded, so I slowly took my spark plug out and then put it back in by hand. It seemed to go in nicely, so I'm hoping it's not cross-threaded.

I replaced the battery this weekend, so I thought I'd check to make sure I didn't get a faulty battery and bought a multimeter. If I can figure out how to use the multimeter, I'll test the battery tomorrow.

In terms of spark, does the "power" of the spark matter? I will check the battery (see above), but does the spark plug wire also need to be checked/replaced? I have visually confirmed spark, but I have no idea if the spark is adequate to fire the engine... How does that work?

Thanks again forum members. I've learned a lot, and I'm trying to look at this as a learning opportunity instead of lost riding time!
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Are we supposed to change our spark plugs?

Battery reads 12.88 volts currently. I haven't tested it while starting (later), but if it is good, what then? Does the spark plug wire matter if I can visually confirm spark (I can)?

Do I move on to compression or could the fuel system still be an issue even though I pulled the hose had the fuel pump push out gas?

You have fuel up to the fuel injector; you don't know yet whether it's getting into the cylinder. That could be a plugged injector, or electrical -- the ECU isn't pulsing the injector. Have you looked at the electrical connector on the fuel injector?

This sound to me as if the spark is insufficient to fire the engine. A visible spark when you test the plug against the cylinder is no guarantee that the plug is sparking in the cylinder when cranking. Under compression the spark resistance increases and the plug may not spark or fire at all. The cause in a case like this is nearly always the plug lead or the plug cap being damaged. The lead may not be properly seated into the plug cap. During removal of the plug the cap and lead can part partial company causing insufficient voltage to get to the spark plug electrodes. I'd replace the cap first and then the lead later if that didn't do the trick. You can smell fuel so it's unlikely to be that. After all, you haven't touched the fuel system, but you have touched the spark plug, cap and lead.

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Thanks again forum members. I've learned a lot, and I'm trying to look at this as a learning opportunity instead of lost riding time!
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I think we are all learning so are grateful that you started this post and for all the thoughts shared. Looking forward to seeing the final solution.

GREAT FORUM!!!

Update from September 5 @ 5:15pm EST - Battery is good and reading 12.8 at rest and 11.7 when trying to start. Next, I'm going to take Stromrider's suggestion to replace the spark plug cap/wire. When the scoot first started having the frequent starting issues, wiggling the spark plug cap could usually get it to start... Until it couldn't. Perhaps this is indicative of a problem with the cap/wire? I'm going to order from ScooterWest:

https://www.scooterwest.com/gts-spark-plug-wire-high-perfromance-080341r.html


Thanks again, forum members.

Not just indicative - it's confirmation!

d'OH!

Update and question from September 7 @ 5:15pm EST - The USPS misplaced the package sent from ScooterWest with the spark plug wire/cap. . I had it sent 2-day mail, but it never made it... USPS opened a case number, but I don't know when I'll have the parts. Question: Are these generic parts, or are they Vespa specific? If they are generic, can I get them someplace else? No Vespa dealers in CT (Vernon or New Haven) have them in stock...

Cap is nothing special, NGK branded part. When I ordered a new one from my multi-line local dealer parts guy offered one he had on hand from BMW parts bin. Pull it off the bike and see if a local shop can match it, auto parts store might even have it. Same for the wire.

He sprayed starter fluid into the intake and it did not start, this is NOT a fuel issue guys.


Ok, see that was figured out before I posted this.

But this is a reminder, don''t guess test. Much faster, easier and lees expensive.

While waiting for the parts....might I suggest that you unscrew the spark plug cap from the wire lead. Then cut 1/4" of the lead for a fresh end, then rescrew cap back onto wire lead. See if that works for you?
O.S.

As to the NGK Iridium plug--- I've installed them in 4 scooters 155》399cc's) with good results. Each scooter had a stronger, smoother idle while sitting in traffic. Noted no other particular differences. It is nice not to worry about crossthreading or stripping these tiny plugs since they are install and forget...

Update and more question from September 8 @ 11:00pm EST - USPS called me. They said the parts were still in San Diego, but all they did was look up the tracking number, which I had already done. They were going to "put a BOLO"(?) into Springfield, MA.

I managed to get the wire and cap off without taking off the foot rest. It was a family affair, as my hands are gigantic and none-too-dextrous. See photos below. The wire connects to a black box near the battery; I think this black box is an ignition coil (or something) and not a voice recorder (like the "black box" on an airplane). I tried OldSchooot's suggestion and clipped of a portion of the wire lead and rescrewed the cap back on and then reassembled as best I could (see below). Still lots of cranking and no starting.

Of course, I do have questions. Without taking off the foot rest, it was not possible for me to crimp the non-spark plug end of the HT wire to the connection in the black box (ignition coil?). I got the fitting to slide on, and I pushed the plastic/rubber boot over it, but I have no idea if the connection is "good enough". For testing purposes, how "tight" must everything be? Do I need to crimp the wire fitting at the bottom of the lead to the ignition coil (see photo)? Or is contact enough for my testing purposes? I'm not putting the battery holder back on top of the battery. And I'm assuming the grey rubber spark plug boot (I think they come in green, too) is non-essential for testing. I don't put the HT wire through the clip harness that holds the HT wire to the frame. I'm assuming all that would be overkill. What do I need to do to make secure connections to ensure I'm testing everything appropriately?

Thanks again Vespa Forum.

For testing purposes, how secure must this fitting connecting the HT wire to the ignition coil be?

That looks good from here. The connector terminals just snap on to the spark plug and coil. They don't need to be crimped. You'll feel them click into place. And you shouldn't need to button everything up, just be sure any exposed wires don't touch anything.

Thanks. By exposed wires, you mean wires not covered in insulating plastic, correct?

Update 9/10/18 @ 8:00pm EST - The Scooterwest parts (new wire and cap from the ignition coil to the spark plug) arrived today. I hooked up the new spark plug cap to the new spark plug and the other lead to the coil. I even used a little dielectric grease on the connections. I hooked up the battery and tried to start... Same exact issue - Turns over and over, but won't start. It almost starts - maybe even does start for a few milliseconds - but in the end, it just won't run.

Last week, the fuel pump was pumping gas from the throttle body with the ignition in the "On" position (the gas was flowing very quickly - around an ounce per second - is that normal?). If the high rate of gas flow is normal, it's probably not the fuel pump. And unless I hooked something up incorrectly (and I may have), it is not the battery, spark plug, spark plug wire, or spark plug cap. It is almost acting like it is flooding when I try to start (perhaps just too much fuel in the mix?).

Could it be something easily overlooked by a novice? I checked the fuses (they looked good)... Anything else that is basic that I could have missed?

In terms of next steps... Ignition coil? Fuel injection? ECU? I'm pretty clueless, but I'm learning, and I appreciate the help.

Have you checked the valve clearances yet?

I'm not saying this *is* your problem, but it could be - and until you know the settings are AOK then you might be chasing your tail until this has been confirmed as up to spec.

I have not checked the valve clearances, but doing so seems out of my ability level. I know that per the manual valve adjustment needs to be done around 20,000km (12,400 miles) and I'm at 8300 miles.

Should a valve clearance check be next? Can I do that easily, or is it time for a professional? Thanks again.

This sounds exactly like the problem I have had for a couple of months. Initially the non-starting was an occasional thing, and I could sometimes clear it by removing the injector and running the starter to clear out any flooding, but that does not work anymore.

Two workshops have told me that my engine is running too rich. So I have removed my Lambda Emulator, re-installed the original injector and even switched back to the OEM exhaust. So everything is now standard except for the air-filter mod. I have checked valve gaps and timing, and installed a new CR8EKB. I have had the ECU software updated and the TPS reset.

I have a beautiful spark at the plug, and fuel sprays out of the injector. But no engine response. It certainly seems like a flooding problem.

My scooter is now back at the Vespa workshop, and so far they have checked that the fuel pressure is correwct. As far as I am concerned the only thing left is the ECU, which I had replaced just before this problem started, because of a different problem - misfiring when cruising at around 100 kph. But two faulty ECUs in succession seems highly unlikely.

The workshop is now checking out the ECU. There are no fault codes there.

Update and questions - 9/11/18 @ 6:00pm EST - I removed the fuel injector and mostly removed the throttle body (I'm not too clear on how to remove the throttle body from the "gas command fitting"). There was lots of gas and gas smell. With the throttle body and injector removed (and the cylinder head exposed), would this be a good time to spray some starting fluid directly in the cylinder head and see if it runs? Or is that a bad idea? Is there anything else I should attempt while everything is opened up?

Thanks again.

I don't have starting fluid, but I did try squirting 10 ml of petrol into the plug hole and then replacing the plug. Didn't work. But I don't know how quickly the petrol would have leaked past the rings while I was battling to refit the plug.

For your experiment I would have thought spraying the fluid in through the air filter while starting was a better bet, but I have no experience with the stuff.

Mike