Help with a 170i

[MTermine]

For the past few years I have owned mopeds, but I finally realized I needed something with a bit more power, so I bought a used 2013 Buddy 170i with 1,700 miles on it. Obviously the previous owner didn't ride it much and it sat from about 2021 until I brought it home. I put new tires on, rode it around the neighborhood adding 5 or 10 miles to it. I thought it ran really well, so I registered it and took it on a more extended ride. Got about 5 miles from home and it died on me at a light and hasn't wanted to start since.

When I go to start it, the engine turns over but it doesn't catch. I tried with more throttle and the engine sounds different, but it still will not catch. If I leave it overnight, it seems to try harder on the first turn and almost catch when I go to start it up. This made me think fuel.

The fuel is new and I hear the pump when I turn the key. I tried checking PSI and borrowed a tester, but I think the gauge was meant for higher PSI engines so it didn't register. However, fuel pumped out from the hose connectors so there is definitely pressure.
I checked spark and it's good. I cleaned the plug and reset the gap just to be sure.
I checked the air filter and it looks clean.
I pulled the cover off the drive belt and it's in one piece. I spun the drive and it felt like there was compression.
The battery is a replacement I bought off Amazon - Mighty Max YTX7A-BS and I use a trickle charger overnight on it. It's the same one I used when I first bought the scooter and used to to drive around the block.

If it matters, the original owner lived in the Hamptons on Long Island and the bike has more rust than it should for it's age, presumably from the salt air. Supposedly it was always stored in a garage and the plastic suggests this is likely true.

I bought a Quick Diagnostic Tool and tried it this morning. I followed the directions and it says there are no trouble codes stored.

Any thoughts as to what it might be? Hoping you can help a scooter newbie...
Michael

[tenders]

What is this “Quick Diagnostic Tool” of which you speak?

You’re sure you didn’t bump the ignition kill switch by your right thumb when you were stopped at that light? Untold time and wealth have been poured into ailments caused by innocent kill switches just doing their jobs….

Are all the fuses intact?

Where is the scooter located now?

[DeeDee]

See if it will start with ether. Search this forum for the 170i ecu reset. I don't recall off the top of my head how to do it. If you have a volt meter, check the battery to be sure it is doing what it is supposed to.

[MTermine]

tenders, the Quick Diagnostic Tool is this http://www.scooterloungeonline.com/product/S320840G01
Supposedly it reads the engine codes but nothing flashed so I assume no codes were stored.

I checked and rechecked the kill switch. It won't even turn over when the switch is engaged and it turns over but doesn't catch when it's not.

Good idea on the fuses - I will check and report back.

Scooter is in the lower Hudson Valley now.

[MTermine]

Thanks DeeDee for the response. Yesterday I began disconnecting the strap that holds the throttle body on but the screw is corroded. I sprayed some Kroil on it and will give it another try, then spray in some starter fluid.

I thought about the ECU reset but I assumed if the diagnostic tool didn't pick up any codes then a reset wouldn't make a difference. But I will definitely give it a try.

I will also check the battery output and maybe even try to start it up with a battery pack.

Thanks for all the suggestions! Give me a day or so and I will report back...

[MTermine]

Update:
I reset the ECU per instructions found on another thread on this forum.
I pulled the injector and there is a decent spray pattern.
I checked the output of the battery and it is 13v
I checked the fuse by the battery and the connector was slightly corroded so I cleaned it up. Fuse itself is good.
I used a jump pack and it tried harder to start but wouldn't run. It did run for 2 or 3 seconds then died again.

Where can I find the fuse box? I see a picture of it in the shop manual but I can't find it on the scooter.

There's no kickstand switch that stops the bike from starting, right? I have put the kickstand up each time just in case, but I was wondering if maybe it's not making a full connection.

Any other suggestions?

[DeeDee]

Did you try starting it w/ starter fluid? Fuel, spark, compression. Back to the basics. On a side note... Boy I love the Buddy 125.

[MTermine]

I didn't because I pulled the fuel injector and it was spraying well. My assumption was that if fuel was coming out well from the injector, then starter fluid wouldn't make a difference. And honestly the screw holding the throttle body on is corroded and fighting me big time to loosen up.

I'll work on loosening it up and give it a shot since I have no other ideas on what to do.

I heard a lot of good things about the 125 but went with the 170i because of the fuel injection. That and the price was right on this one. Now I'm starting to question my decision!

[MTermine]

DeeDee, I drilled out the hose clamp screw and was able to spray starter fluid down the throttle body. Unfortunately, it still wouldn't turn over.

Any other suggestions?

[ohiomoto]

Doesn't catch? I assume you mean it cranks over and tries to start but won't run.

It's doubtful that a low-mile motor melted down and lost compression during a short ride, but you should test the compression. You already confirmed that you have spark and fuel. I think all you have left is control over the fuel delivery. It could be a temp sensor, a broken wire, or a problem with the EMS.

The service manual has a list of troubleshooting steps. Page 19 goes over cold start issues which is where you're at now, but it could be anything since it died so suddenly.

[sc00ter]

Is it getting spark? I know that's a simple question but you need to verify its getting a nice strong spark.

Another thing. Flip the kill switch a few times. I've seen corrosion get in the switch assembly on bikes/scoots that live by the water.

Finally, is the air filter wet? If the air filter gets wet it will not always let the scoot start. I dropped a air filter to a back pack blower into a jar of gasoline and "thought" it was dry. I couldn't start that blower for nothing! I had to pull the filter out and hit it with compressed air.

You only need a quick squirt of starter fluid. You remove the air filter and spray a dab in inlet.

Keep us posted!

[MTermine]

For clarity, if I leave the scooter alone for a bit, especially overnight, the first time I try starting it the engine runs for a few seconds and then stalls. During that few second run, if I engage the throttle it stalls quickly. After the first time trying to start it, the engine tries to run but doesn't.

It has spark and it's a nice blue color.
I pulled the air filter and sprayed starter fluid into the tube but there was no difference.
I tried it with the air filter off completely to see if there was a restriction and tried to start it but there was no difference.
I pulled the exhaust off to see if there was an exhaust restriction and tried to start it but there was no difference.
I flipped the kill switch many times, but there was no difference.
I tried starting it with the kill switch down and there was no response from the engine, but there is a response when the switch is up, so I suspect the kill switch is not stopping it.
I tried starting it with a jump pack and there was no difference.
I checked the voltage from the battery while trying to start it and it was fine.

There's no engine codes being triggered, which I would guess would happen if it were a sensor or a big problem.

What's the chance that it's the injector? I pulled it and it sprayed a nice pattern, but I'm wondering if it's because I am turning it sideways. So if something was clogging it, when I turn it sideways it wouldn't cause a blockage, but once it is back in place and the fuel pump puts pressure on it, the blockage comes back. That would also explain why no codes came up - the computer senses pressure but doesn't realize nothing is spraying. But...wouldn't the engine then run when I sprayed starter fluid?

I ran through some of the steps on page 19 of the troubleshooting chart and need to remove some body panels to access the engine temperature sensor. I will give that a go this weekend.

I VERY MUCH appreciate the suggestions - please keep them coming!

[sc00ter]

Fuel pump failing? Was there ever a recall on the fuel pumps or known issues? I hate modern vehicles so my trouble shooting tips wont be the best. I would say run a a tank of Techron fuel system cleaner thru it but it would have to run first..... Again, my modern EFI trouble shooting skills are limited.

Could it be vapor lock? I'm not sure you can run a Buddy 170i with a loose fuel cap to check for vapor lock.

[DeeDee]

What's the chance that it's the injector?

If a shot of ether doesn't get it to fire, doubtful It's a bad fuel injector. Same thing for the fuel pump and vapor lock.

[tenders]

Yes. Lack of firing on ether is telling you that no spark is happening in the cylinder when the ether is present. That is happening for one of two reasons: there is no spark, or the ether is getting very efficiently flushed out of the cylinder before the spark takes place. The latter is pretty hard to do, so I would investigate the former.
* If it runs for a little while when cold, is it possible that the coil is bad? The insulation layer around the extremely thin wires in the coil can ground the coil out when it warms up a bit.
* Is it possible that there's a break in the spark plug wire when the plug is in place, but not when the plug is being tested?

[MTermine]

It runs for a bit when cold which tells me the plug is firing. And it stalls without anything moving, so I do not think it is the plug wire. But the coil is an intriguing idea. Any suggestions on how to test it?

[DeeDee]

Could also be a problem with the stator ignitor. I haven't seen this on a 170i, but I have had these type of systems on a 1st generation Honda Metro and a Buddy 125.

[tenders]

But the coil is an intriguing idea. Any suggestions on how to test it?

Aside from replacing it, perhaps with a cheapo Chinese one for testing purposes, I don’t know how to diagnose an intermittently failing coil. Looks like a Chinese one is $20 and the OEM is $60.

[az_slynch]

I saw something similar to this on a 2014 Like 200i.

It would start, run for a few seconds, falter and die.

I went through the gamut with it. Had the injector tested. Pulled the throttle body and cleaned it until spotless. Checked the battery again and again.

The problem turned out to be the hose from the pump to the pressure regulator. The hose had rotted and sprung a leak. The engine got fuel when the scoot primed, but once it was running, it couldn't maintain pressure as that bit of hose just leaked more as the pressure built. Since this all lives in the fuel tank, it was not apparent until I finally pulled the pump assembly out.

The Kymco diagnostic box couldn't figure out the pressure drop, but I could see the 02 sensor going lean and the ECU retarding timing prevent preignition.

If this sat for a long time, the hose in your pump pack may have rotted. Plan to pull it and to replace the line with a bit of hydraulic hose, ATF cooler line seems to hold up. Be a bit generous too, so it doesn't pull off of a barb. If it's rotten, also make a point of cleaning the bejesus out of the pressure regulator and the ports in the top of the pump assembly.

[MTermine]

All great suggestions - thanks everyone!! I will run through the suggestions over the next week and report back with an update!

[DeeDee]

if the engine won't fire with ether, you can spend a week cleaning/replacing hoses and fi components, it won't make a bit of difference.

[ohiomoto]

DeeDee is right it should run on starting fluid.

It starts and stalls on a cold start. That tells us that you have fuel and spark. Stalling on a cold start normally indicates the enrichment circuit or "choke" is not providing enough fuel for the cold start. That's where starting fluid comes in. Its purpose is to help get a cold engine running long enough to run when it's lean on fuel.

The fact that it won't run on starting fluid is odd. You should remove the air filter and spray the starting fluid into the airbox while the engine is cranking with the throttle wide open. It should start and run until you stop spraying.

If it runs on the sauce it's likely a fuel delivery or problem.

The curveball is that it ran for a few miles before dying. That's why you should confirm good compression by testing it.

[scootERIK]

For clarity, if I leave the scooter alone for a bit, especially overnight, the first time I try starting it the engine runs for a few seconds and then stalls. During that few second run, if I engage the throttle it stalls quickly. After the first time trying to start it, the engine tries to run but doesn't.

When it does start does it start right away or does it take a lot cranking before it starts?

[MTermine]

When it does start, it starts after maybe two seconds of cranking, then runs for a few seconds. After that initial start, it won't start up again for some time, usually overnight.

I think we have ruled out fuel, but I will re-try starter fluid again just to be sure.

I ordered an ignition coil and will try that when it is delivered.

I will be spending some quality time with it this weekend and will check compression, but if that were the case why would it run when cold and then not again? If compression is the issue, shouldn't I get the same results each time?

[DeeDee]

Crank your throttle wide open, then shoot a blast of ether into the air intake, then pull in the brake lever and push the starter button.

[MTermine]

Tried the starter fluid again and nothing.
Checked all the fuses under the front panel and they all look good.
I pulled the engine temp sensor and the readings were within the correct range.
I tried the Quick Diagnostic Tool again just in case I messed up last time and got no readings. Whatever this issue is, it does not seem to have triggered a check engine code.
I pulled the fall over sensor and the balls seem to be moving easily but I could not locate how to test them with a multi-meter. I used it anyway and there was no connection beep between any of the three prongs with the sensor either upright or lying down. Is this normal?

Ignition coil was ordered and should be delivered tomorrow. I hate to throw parts at it but I figured it was always good to have an extra anyways.

I rented a compression tester at Auto Zone and found out when I got it home that the threaded end is only M14 or M18. If my Googling is correct, it looks like I need an M10. Tomorrow I will make a run to HF and pick up a long overdue compression tester that I probably should have bought years ago.

I will send another update either tomorrow or Sunday. Wish me luck and keep the suggestions coming!!

[tenders]

Whatever gremlin you’re struggling with should be quaking in its filthy boots, now that you’ve invoked Harbor Freight.

[DeeDee]

I'm throwing this in out of left field. I had a similar problem with my Burgman 400. I have a riding buddy who is an ASE certified Audi mechanic and fellow scooter fan. He has a very expensive scooter diagnostic tool with fittings for all major brands. Short story version is it ended up being a faulty fuel injector with an intermittent problem. I like you, pulled the injector early in my search and saw a strong V shaped pattern. In my mind, clearly not the injector. This was never picked up by the scan tool. We solved it on the 3rd night. I had the same year Burgman in for a belt change, we started swapping parts. My scooter was down for 3 months, and I'm a fairly decent mechanic. I had help from a guy who knows more than I ever will. At one point I was seriously looking at options for parting the bike out. Moral of the story, is scan tools don't show every possible problem, and sometime you have to throw parts at the problem.

[DeeDee]

Also....take what ever compression reading you get with a grain of salt unless you have another 170i sitting right there you can do the same test with the same equipment on.

[MTermine]

Thanks DeeDee and tenders! Anyone have suggestions on how to check timing on the 170i? According to the manual, there is "no need" to adjust timing but rather it suggests that the ignition system be checked. It then gives a short description of how to check while the engine is idling, but I can't get it to idle.

[MTermine]

Compression is right around 140.
I installed the new OEM ignition coil and that wasn't it.

I went to pull the valve cover off and snapped a bolt. Anyone know a good Genuine shop in the lower Hudson Valley?

[tenders]

Oh, man. Nothing like a snapped-off bolt to up the stakes.

My toolkit for this problem involves a set of left-hand cobalt bits and EZ-outs. The trick is to use the bits until there’s almost nothing left for the EZ-out to grab. It is very difficult for our species to resist the urge to use the EZ-outs too early.

I don’t know how eager NY PowerSports in White Plains will be to work on Buddies, but they’re Kymco, Vespa, Kawasaki, and Aprilia dealers and are otherwise quite competent. There are Buddy dealers in New Danaan, Milford, and New Haven.

[MTermine]

Holy cr*p you are not going to believe this...I got it started and running!

My son, who is into mopeds, has been offering suggestions all along as well. As a "why not try it" type of suggestion, he said to clean the threads of the plug. Turns out he had a moped with a similar no start issue. The threads of the plug (not the tip but the threads) were fouled and it wasn't grounding when it was installed. But, it grounded when pulled since we all put it against the frame.

I replaced the plug and it started right up. Now the job is putting all the body panels back and taking it out for a spin!

Hopefully this was truly the issue but I will let you know!

[tenders]

Wow! No need to argue with success, but that (= # of threads in the block x circumference of threads) seems like a lot of linear distance to be completely electrically insulated from the high voltage of the plug spark.

I wonder if there was something else going on in the plug.

I haven’t seen a modern spark plug stop working in decades - cars, scooters, boat inboards (though some have rusted badly), outboards, generators, pressure washers.

[MTermine]

Just took it out for an almost 20 mile run and it did great!!

Same with me tenders, especially that the threads fouled and not the tip. Maybe because it sat in salty air? Maybe it wasn't tightened enough by the PO? It's odd that it worked when grounded to the frame. Another day I think I will clean up the threads on the old one and see if it runs.

Thanks to everyone for all the great suggestions! And more so, thanks for the encouragement to figure it out!!!

[ohiomoto]

That's amazing! I would have never suspected something like that. Glad you figured it out.