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Post by dishe on Sept 7, 2008 9:21:53 GMT -5
So, I was riding the other day when suddenly there was a popping noise, and the scoot lost acceleration. Something definitely didn't sound right, so I turned it off and walked it to a neighbor's driveway.
When I started inspecting it, I found the sparkplug was being held on by the electrical boot, and was not actually attached to the engine anymore.
I luckily had some tools in the trunk to reseat the sparkplug, but without a proper toolbox, I wasn't able to fully tighten it apparently.
I started my way home, and made it up a very steep hill before the same noise and loss of power happened again. Sure enough, the sparkplug must not have been in well enough, and popped out again.
At this point, I was able to walk it the rest of the way home to go at with a real set of tools, and managed to seat the sparkplug properly.
I took it for a couple of rides, and the sparkplug hasn't popped out again, however the scoot is CLEARLY not the same. It seems much more sluggish now, trouble accelerating and lower top speed (40mph at best).
Also, the scoot seems to stall whenever idle for more that a few seconds. I had to restart it at every stop sign or red light, and it took 5-6 tries to start it when the engine i cold.
Before the plug popped out the first time, everything was fine. What do you guys think? Has this experience caused damage to my equipment? What can I do about it?
The plug was a year old NGK-CR7 non-iridium that I bought to replace the stock one. Could this have destroyed my plug? Do you guys think I should buy a new one?
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Post by agent22 on Sept 7, 2008 9:31:57 GMT -5
i would at least check the gap on it. I would think its about time to replace it if it has been a year.it very well maybe asking you to throw it away by popping out . it is probably broken.
A new iridium is only like 7 bucks. i also recommend putting some anti seize on the plug and don't over tighten it.
hope this helps.
how does the spark plug wire and cap look?
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Post by motomech on Sept 7, 2008 9:32:14 GMT -5
Yeah, buy a new plug and install it with a torque wrench this time.
You obviously didn't get it tight enough.
Inspect the threads in the spark plug boss, if they are damaged, the head will have to come off to be repaired/replaced.
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Post by harrywr2 on Sept 7, 2008 9:38:43 GMT -5
The real question is what caused the plug to pop out to begin with. I would try a new plug.
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Post by dishe on Sept 7, 2008 16:20:05 GMT -5
Well, I just took out the spark to inspect it, and check this out- I think when the spark plug blew out (twice), it started to rip at the spark plug threading. Looks like the last time I tightened it, it started to take some of the surrounding metal from the shaft with it. Take a look at these pics:    See the light silver-colored shavings? they come out when prodded with my fingers. This can't be good. Will a new spark plug even help, or am I shafted (pun intended)?? I'm wondering if the spark plug isn't even making a good seal anymore, which could lead to the loss in power accelerating, etc. What do you guys think? The question is, as harrywr2 said, why did this happen in the first place? also, agent22, I believe spark plugs are supposed to last way more than a year, especially on a little bike. In some cases, you'll probably need to change them once or twice in the lifetime of a vehicle. So, anyone got any pointers for a good cheap place to get an iridium to try? I was going to hit up ebay, but I'd like to find someplace that would ship faster... |
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Post by bravobravo on Sept 7, 2008 16:27:23 GMT -5
If the spark plug keeps blowing out you probably need to heli-coil the cylinder threads! Ive had to heli-coil a few engines before... They make a kit that will give you everything you need. They sell them at NAPA, just need to know the thread size of your plug, wouldn't be a bad idea to change the plug while your at it.
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Post by wildman on Sept 7, 2008 17:11:21 GMT -5
have to agree with bravo. that is cylinder head in the threads. a helicoil is the fix and yes the head needs to come off. you need to clean out the cylinder anyway. failure to remove the shavings in the cylinder will result in a scored cylinder. this will require a whole new cylinder and piston.
sorry for the bad news, but maybe you caught it prior to any real damage.
chuck
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Post by dean on Sept 7, 2008 17:41:05 GMT -5
I guess that means you will have to start a new thread...get it? haha
I've seen lots of goofy things happen to these chinese scooters but this one has to take the cake.
--- cakes rise when I enter the kitchen
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Post by harrywr2 on Sept 7, 2008 18:39:21 GMT -5
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Post by motomech on Sept 7, 2008 18:40:57 GMT -5
Don't quote me on this(not that anyone here has ever quoted me), but I think a Time-Sert would be the way to go on that.
Note that the crush washer has not been crushed, it was put in hand tight, as I said.
I would suggest he take it to a shop. If he couldn't correctly install a spark plug, there is not much chance he can remove the head, repair the boss, and re-install the head.
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Post by funderp47 on Sept 7, 2008 19:27:18 GMT -5
I would first try to "chase", or clean up the threads with a tap, and see if the spark plug will reinstall to the proper torque. Use anti-seize. If it does, I would never take it out unless valid testing shows the plug won't fire.
This forum is full of tales of needless plug changes. It increases the chance of problems. Wastes money. An inline spark tester will tell you if the plug is sparking or not. If not, removing the tester's end from the plug and grounding it will show if a spark is being produced. That clears up ignition stator coils, cdi, coil, spark plug wire, end, and plug with one easy test.
The inline tester is as cheap as the highly overrated iridium plug also read about here.
If I couldn't clean up the threads myself, or install a helicoil or whatever, I would take it somewhere. This is a very minor problem in the life of a mechanic.
I realize removing the plug to check plug color is important to tuning. A trained ear will learn to hear rich and lean deviations from normal after getting the mixture right.
Locals cross-threading plug holes have bought me a variety of installation kits and taps over the years for installing timeserts and helicoils.
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Post by motomech on Sept 7, 2008 20:36:57 GMT -5
<<<I would first try to "chase", or clean up the threads with a tap, and see if the spark plug will reinstall to the proper torque.>>>
I believe it's too late for that. He has lost a whole thread that we can see, but more have been damaged.
<<<Use anti-seize. >>>
I always install them "clean and dry".
<<<<This forum is full of tales of needless plug changes. It increases the chance of problems. Wastes money....>>>>
I would agree with that 100%. A Japanese plug should be good for at least 6000 miles in these things.
<<<I realize removing the plug to check plug color is important to tuning.>>>
With today's clean burning fuels, unless it's running super lean, that is not much to be seen.
The whole "plug reading" thing is way over-blown.
The best way to know if it is too lean on the main jet, is if there is surging on the top-end.
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Post by lankeeyankee on Sept 7, 2008 21:44:00 GMT -5
Many make the mistake with spark plugs and aluminum heads.
These are the big DO NOT DO"S
1) Remove a spark plug when the engine is hot.
2) Over torque when installing the spark plug.
3) Not using anti sieze on the plug threads.
He has stripped the threads.
1) Install a heli coil
2) Remove the head when doing this, or you will wind up with metal shavings in your head that will scar the cylinder walls.
As another post stated
I would recomend him taking it to a shop or have a mechanic perform this, since he doesnt seem very mechnaically inclined.
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Post by dishe on Sept 7, 2008 22:14:28 GMT -5
Believe me, I would LOVE to take this to a shop- problem is, the guy I bought this from is unreliable as his lead mechanic skipped the country, and there aren't any other good places around that will deal with chinese scoots.
As many of you could tell (or remember from when I was more of a regular here about a year ago) I am not mechanically inclined enough to feel comfortable attempting to remove the cylinder, nor am I familiar with using a helicoil.
I don't know what caused the sparkplug to pop out in the first place, but it's been happily chugging away in there for about a year since I first changed it. After re-seating it properly, it seemed to stay in, although I have this loss of power.
My options at this point are:
1) Put the plug back in and drive with it like this until it dies.
2) Get a new sparkplug, drive with it like this until it dies.
3) Sell it and buy a Honda
4) Let it sit and collect dust.
Is there a chance that a new plug would make all this go away? If you notice, only the threading towards the end of the plug were coming off- in other words, the rest of the cylinder would still hold it in.
(I'm guessing that's about as far as I was able to get it in with the tools I had on the road until it popped out the 2nd time, stripping those threads)
I'm hoping that the sparkplug was damaged by this, and replacing that would at least get me a little bit more life out of this scoot until a shop decides to open up in my area.
What do you guys think?
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Post by lankeeyankee on Sept 8, 2008 0:09:03 GMT -5
Dude, your cylinder head spark plug threads are trashed!!
No putting a new spark plug in wont help. A spark plug threads are made of a harder metal than your cheap chinese aluminum head. You stripped the threads out either by one or 2 things. You either cross threaded it or you over torqued it and pulled the threads. The reason you are losing power is cause compression is leaking past the spark plug.
Here are your options.
1) Find a mechanic that can work on a small 4 stroke engine.
2) Remove the engine and take it to either a lawnmower shop and hope they are nice and will do the 15 min job of a heli coil.
If you arent mechanically inclined or have any friends that can work on engines you shouldnt have purchased a chinese scooter, they require work, they arent hard to work on if you have mechanical skills and there is tons of information out there on the GY6 engine
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Post by motomech on Sept 8, 2008 0:09:18 GMT -5
<<<I don't know what caused the sparkplug to pop out in the first place, but it's been happily chugging away in there for about a year since I first changed it. After re-seating it properly, it seemed to stay in, although I have this loss of power. >>>
I will repete this for you;
"Note that the crush washer has not been crushed, it was put in hand tight,..."
"You obviously didn't get it tight enough."
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Post by funderp47 on Sept 8, 2008 8:07:52 GMT -5
I would first try to "chase", or clean up the threads with a tap, and see if the spark plug will reinstall to the proper torque. Use anti-seize. If it does, I would never take it out unless valid testing shows the plug won't fire. Hey motomech, I used some important IFs in that first sentence of my last post. It's hard for me to tell from internet descriptions and pictures what is going on. IF you chase the treads and IF the plug torques down, it MIGHT stay in place. IF it crushes the washer, it PROBABLY will. At least that has been my past experience, to the relief of someone facing more expensive solutions. Good catch on the crush washer. For a long time screwing the plug down to the crush washer, and then just feeling the crush washer collapse, was the only way I had for installing plugs. |
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Post by dishe on Sept 8, 2008 9:14:39 GMT -5
Wow, when did this forum become so condescending? If you arent mechanically inclined or have any friends that can work on engines you shouldnt have purchased a chinese scooter, they require work, they arent hard to work on if you have mechanical skills and there is tons of information out there on the GY6 engine Lankee, before you go giving people "advice" on scooter purchases, you should just know that I've been riding this thing for going on 3 years now, and if you'd have been a regular on this forum at least a year ago, you'd have seen me around sharing my experiences and findings. Heck, I redid half the electrical wiring on this thing, but this is the first major problem I feel I couldn't handle myself. Yes, I admit that I'm not your most mechanical person, but as you said yourself, these things are not hard to work on. I've had my share of problems, including air intake issues, faulty electrical (blew out my first battery, had to rewire one of my blinkers, and remove the malfunctioning hi-low beam switch, all on different occasions), a bent tire rim, muffler rivets falling out, clogged carb... But most of those were relatively simple to deal with, and for the problems I wasn't familiar with I found help here. For what I paid for the scooter, most people would be happy it ran for almost 3 years and say it had a good run while it lasted. That being said, if I could fix this and have it last a while longer, it would be great, but if it died now I'd still say it was worth it. Either way, the condescending attitude is unnecessary. ~~End Rant~~
Back to what I should do...moto and funder, you guys think it was just never seated properly the first time? Hmmm... I guess its possible, the irony is that I was so nervous about stripping those threads I went gentle on tightening it the first time I changed it. You think if I thread it in and get it to stay, I should just leave it and go? The thing is, if I'm losing power because its leaking pressure by the plug, can I seal that up with something? |
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Post by unk on Sept 8, 2008 12:14:46 GMT -5
One of 2 things caused the plug to come loose, over tightening and stripping the threads or not tightening it enough and it bounced around and damaged the threads. If it tightens down leave it and run with it. I had a outboard motor that I stripped one of the heads out years ago and it is still holding. If it is leaking around the threads check with an auto store for a high temp thread sealing compound. The only bad that can happen is you will need a Heli Coil and any mechanic can put that in, it does not have to be the shop you have gone to.
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Post by mx5tc on Sept 8, 2008 16:57:32 GMT -5
Don't feel bad, I've got a plug out my Crown Vic 4.6L Modmotor Ford that looks the same! Timeserts are arguably better for repairing sparkplug inserts than Helicoils, but the labor cost for the repair (not counting your time to pull the head) is going to bump right up against the cost of new bare head. As another poster suggested, taking the head off and taking it to local indy lawnmower/garden tractor shop is most likely going to get the lowest cost repair.
Good luck with it, and remember to use a torque wrench on the repaired or new head!
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Post by funderp47 on Sept 8, 2008 19:06:26 GMT -5
dishe, if you are correct about having good threads in the hole with just a small portion damaged, I would clean up the threads with a tap (thread chaser) and try a new plug and see if it torques down. The problem is access to enable seeing that the tap is started straight. If the threads aren't too buggered up, it should turn easily. If you are REALLY lucky, you could simply try installing a new plug with known good threads. If it doesn't turn easily, don't force it.
I have installed numerous helicoils and inserts (timeserts, bushings, etc) with the head on the engine, both on cars and motorcycles. Sometime, if fairly undamaged, I cleaned them up with a tap and spun the engine with the starter and let the compression help clean it out. Using grease on the tap helps the particles cling to it instead of falling on the piston.
I have used thin strips of cloth, slathered with grease, pushed through the hole and wound on top of the piston to catch stuff, then pulled it back out with a wire with a hook on it. An installation tool for a helicoil or insert is typically only about 2mm larger than the original 14mm hole. I am assuming your scoot uses a 14mm plug.
I never experienced any damage from particles falling on the piston, and after a number of successes, started using the grease and blowout method even for helicoil installation. A small piece of cloth saturated with gas, carb or brake cleaner will remove the grease and sparklies from the threaded hole. When turning the tap, go a little at a time, remove, clean off particles, regrease, go a little further, repeat.
You never know until you try. Auto parts stores have what you need, either a thread chaser (tap) or plug hole repair kits. Getting to it and seeing what you're doing is the worst part. Good luck.
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Post by chaajoad on Sept 8, 2008 20:38:46 GMT -5
dishe - I guess my post is predictable but ... sell it and buy a Honda. One warning: if you do that, you'll be reduced to pretty much a reader here rather than a poster. In all the decades I've ridden Hondas and Yamahas and even CSS, I have never once heard of a spark plug popping out. You're correct - three years is a good run. Now buy something that will run for thirty.
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Post by greg on Sept 8, 2008 21:01:29 GMT -5
3 years is a good run? wow.. i hope mine lasts 10!
yup a small engine repair shop just call around till you find someone that sounds interrested to help..but you could allways try. take it one step at a time. one day take off a few panels next week the head.... as your doing that enjoy the purchase of another. like the linhai 300??
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Post by dean on Sept 9, 2008 0:23:32 GMT -5
dishe - #3 - just put the plug back in and sell it....fast! It will only take a couple days. Use that money to buy the Honda (or Yamaha or Suzuki, etc). Then the next time greg's scooter stalls out on him or he has a gas leak you can give him a lift.
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Post by mortar235 on Sept 9, 2008 0:33:43 GMT -5
dishe - just put the plug back in and sell it....fast! It will only take a couple days. Use that money to buy the Honda (or Yamaha or Suzuki, etc). Then the next time greg's scooter stalls out on him or he has a gas leak you can give him a lift. i hate people like you |
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Post by dishe on Sept 9, 2008 10:00:49 GMT -5
I'll be honest, I've loved owning a chinese scoot, and while the thought HAS crossed my mind, I'm not so sure I'd spend the money on a more expensive Japanese name brand just yet.
Man, you guys are quick to dismiss and/or give up! I mentioned that as an option but didn't think you guys would suggest it!
Maybe I'd go for a better chinese one first... Did I mention this thing I'm driving is a SunL?
Yeah, not exactly the best choice in chinese scoots, but it was hella cheap and hence the "glad it lasted 3 years" thing.
Maybe I'd look into a strata next, since "Scootdawg Lee" gave it a glowing review as far as build quality.
But, all this stuff is beyond the point... For now, I'll try to clean out the cylinder a bit, reinstall the plug and drive it until I decide what do next. The loss of power is annoying, but its better than driving a car for local trips. As long as I can get it to stop stalling when I come to a stop... going to try some sealant or something as mentioned earlier in the thread.
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Post by dean on Sept 9, 2008 12:19:50 GMT -5
dishe - if you don't mind the ongoing repairs and inconveniences you should probably stick with a chinese scooter. Maybe even take greg's advice and buy another so you can be riding one while fixing the other. I just think that one high-end one is better than two low-end ones. You can get the high end one for about the same cost as the other 2 and do more riding.
Another thing to consider is if you want the high-end scooter but think you cannot afford one, just think how much harder it will be to afford after buying another chinese scoot. Save, save, save your money and do the right thing when the time is right.
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Post by scootwes on Sept 9, 2008 18:15:05 GMT -5
Correction, dean. You could buy about 4 or 5 Chinese scooters for the price of a Vespa or Honda! Most of us are here exactly because we can't afford Japanese or Italian. We are glad you can, and we don't begrudge you that. We're happy learning to be mechanics as we go. Eventually we too can reach your exhalted status as "The Most Interesting Man in the World" (did it take you long?).
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Post by dean on Sept 9, 2008 22:18:25 GMT -5
scootwes -- My response has nothing to do with you or anyone else excpet dishe. I have no idea who can aford what and neither do you. He asked a question and i answered it. Too bad if you don't like it. And he definitely shouldn't shop where you shop.
-- I can afford anything by just walking into a bank
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Post by scootwes on Sept 10, 2008 0:30:26 GMT -5
This is a PUBLIC forum. Your answer is a public answer, and the public (and myself) has every right to comment on everything posted. If you don't like public exposure, then write a private email to the guy.
Looks like you are a pretty anti-social guy, as evidenced the NEGATIVE 57 BONES!!! I guess that's pretty much a record on this forum, you must have annoyed a large number of people! Listen, Dean, why don't you change your whole approach and try being positive and helpful, instead of dissing people and their choice of scooters? 99% of us are on Scootdawg to help each other, and life is much more fun when you take that approach . . .
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