Honda Wave frequent spark plug failures

[KeeTua]

We have an older Wave 100 carburetor model that has frequent spark plug failures, weak to no spark. Thinking I might be getting NGK copies from the small shops in town I bought the last 2 plugs from the Honda dealer and neither made it beyond 500km of easy village driving. The bike is in pretty good shape but because of its age and this problem I decided to go through it and replaced the CDI unit, coil, plug, plug wire, plug connector, fuel filter andnew carb. All parts appeared to be Honda OEM including the carb. On top of that tires, shocks, chain and sprockets etc. It was running great then the spark plug failed at 350km. The plug looked good, a tad darker than I like to see but not black. I just ordered a few NGK plugs from Shopee to try a new source.

Anyone hear of a problem like this? Any ideas?

[kickstart]

Got to ask the obverse did you replace the air cleaner ,that would make the plug a bit on the black side. 

But I would say being an old bike ,is it using any oil, worn piston rings worn bores that would make the plug a bit black, give it a weak spark.  

[Kwasaki]

 

3 hours ago, KeeTua said:

Anyone hear of a problem like this? Any ideas?

A short life with spark plug and failure is mainly caused by bad timing or the bikes engine is running a very lean mixture.

[papa al]

How did you determine that the plug was bad?

[Denim]

Lots of very short journeys at low speeds can lead to deposits in the engine. A few long runs at speed can burn this off.

 

Our older wave also had this issue a few weeks back. Would not start at all. Cleaned the the plug thorougly and it started first kick. However , had to keep the revs up to keep it from stalling. Reving it like this brough clouds of white smoke for a minute or so but this slowly got less and less until it ticked over normally. Then took it for a 10 k run at 80kph and its been fine since.

[Agusts]

I had spark plug problem on my Forza a month or so ago, after the service that put new NGK plug (I bought it off Lazada) and as it happened using two tank-full of Shell Premium gas, thinking it might be good for engine clean as it has more cleaning detergent...!

 

Absolute nightmare for weeks, nobody knew why the bike idled badly, two or three mechanics and myself checked everything, new air filter too,  Honda dealer put it on computer, found nothing...!

 

All of them opened and looked at the new and old plug, tried another used plug they had, I even checked my old and new plugs with ohm meter, all seemed okay...

 

I opened and adjusted the gap a few times but it eventually stopped working completely, bought a new plug - identical in every way - and problem solved, idling perfectly ever since...!!!

 

I also thought maybe the one I bought was a copy, but we tried my old plug and another used plug with same issue...

 

Theories were mostly I used bad fuel, but since the problem had started I went on a trip and changed 4 or 5 tank full with my usual fuel from ptt...! 

 

I suspected mostly the mechanics who never use torque wrench here, may have tightened the plug too much and damaged it, Forza has an awkward angle for plug change, need two attachments..., idling would get worse every time they opened and closed it to check....!

 

At the end no one is wiser, I'm not touching this plug for another 24k km, maybe never ever...! Honda wanted to bring down the engine with many days work and huge cost...., even though Forza is not considered a big bike , they charge the same for repairs, everything with it is rip off compare to other scooters....!!!

 

As for your problem, you have tried different plugs, and changed everything, also empty and drain fuel tank and hoses (they told me this too), but ultimately as an old bike maybe the problem is inside the engine, valves, cylinder and piston..., I had an old Suzuki scooter that had idling problem , eventually solved by an engine overhaul , costed a measly 1600b altogether....! 

 

[kickstart]

10 hours ago, Kwasaki said:

 

A short life with spark plug and failure is mainly caused by bad timing or the bikes engine is running a very lean mixture.

Timing with CDI ignition is not a problem ,the OP said he has changed the CDI unit ,but normaly they work ,perfectly the whole time or they do not ,and the unit needs replacing .

I had a Kawa GTO ,and I did wonder about the timing ,so I brought a strobe light ,timing was spot  on .

If it was running very lean the plug would be almost white .

[Kwasaki]

1 hour ago, kickstart said:

Timing with CDI ignition is not a problem ,the OP said he has changed the CDI unit ,but normaly they work ,perfectly the whole time or they do not ,and the unit needs replacing .

I had a Kawa GTO ,and I did wonder about the timing ,so I brought a strobe light ,timing was spot  on .

If it was running very lean the plug would be almost white .

We know that but it's either those two things if everything else is OK or just bad plug or wrong plug. 

Unless OP Quotes back we'll never know. ????

Edited April 28, 2021 by Kwasaki

[KeeTua]

16 hours ago, kickstart said:

Got to ask the obverse did you replace the air cleaner ,that would make the plug a bit on the black side. 

But I would say being an old bike ,is it using any oil, worn piston rings worn bores that would make the plug a bit black, give it a weak spark.

Yes, replaced the air filter too. The bike doesn't seem to use any oil, nothing added in between changes and no signs like smoke or smell.

 

13 hours ago, Kwasaki said:

A short life with spark plug and failure is mainly caused by bad timing or the bikes engine is running a very lean mixture.

Wouldn't hurt to check the timing but the color of the plug didn't indicate a lean mixture. It's possible the plug is getting darker as it is starting to fail I plan on checking the color of the current after I run it for a while.

 

6 hours ago, papa al said:

How did you determine that the plug was bad?

Grounded it to the head and pushed the kickstarter a few times. Barely a spark and it would spark some at the threads not just the electrode. The plug I used for a replacement had a nice crisp spark when grounded to the head and the engine fired up and ran great on the first kick with the new plug installed.

 

5 hours ago, Denim said:

Lots of very short journeys at low speeds can lead to deposits in the engine. A few long runs at speed can burn this off.

That's something I wondered about also, frequent very short trips no way enough time to get up to operating temp. The plug had a few very small deposits at the electrode but the gap was clean. I have been taking it out to exercise it since I did all the work on it but I don't do it every day.

 

3 hours ago, Agusts said:

As for your problem, you have tried different plugs, and changed everything, also empty and drain fuel tank and hoses (they told me this too), but ultimately as an old bike maybe the problem is inside the engine, valves, cylinder and piston

I did replace the fuel line from the tank to the carb including a new in line filter. Drained the gas and put in gas from PTT. Strange thing was I found an additional in line fuel filter just below the tank nicely hidden from view. It wasn't an original Honda filter and why would someone put 2 filters in the same line? I thought maybe someone used an older filter to repair damage to the line instead of replacing the entire line. That was about the most funky thing I've found on the bike outside of the usual mismatched or missing fasteners and signs of rodent damage.

 

The bike runs so good when the plug is working that its hard to imagine there's internal engine problems. It's got 45K km on it and as far as I know the engine has never been opened up.

 

1 hour ago, Kwasaki said:

We know that but it's either those two things if everything else is OK or just bad plug or wrong plug. 

Unless OP Quotes back we'll never know.

NGK C7HSA plugs as the owner's manual calls from. Sorry for the late replies. We had some good early rains and the wife put me to work.

[Kwasaki]

8 minutes ago, KeeTua said:

Wouldn't hurt to check the timing but the color of the plug didn't indicate a lean mixture. It's possible the plug is getting darker as it is starting to fail I plan on checking the color of the current after I run it for a while.

I guess all you can do is keep an eye on it and carry a spare plug.

Not only lean but rich mixture with timing slightly out can cause plug fouling, I take its air-cooled so could be running too hot.

[Agusts]

I had a lot of advice about checking plugs, I can write a book about it...! lol

 

The colour of the electrode is the key if mixture problem, also next time try to clean the electrode and ground with a fine sandpaper when it goes bad (they say some fine build up , hard to see, weakens the spark), check and adjust the gap too...

 

They say Ohm meter check is useless but worth it in my opinion, must compare with another new/old plug, also check with it any leak from electrode to porcelain/ceramic part and the ground, should set it to KOhm to see any leak...(a mechanic had this but had no idea how to use it, so I took it and checked myself) !

 

I also checked the sparks against ground metal visually , then again they say a weak spark (red) or strong (blue) can not be quite identified, need high voltage apparatus to check exact spark real/correct power...

 

I hope you find the issue and it's not costly , it's amazing once it's resolved, great feeling, and you wonder how on earth I missed that  .....!!! ? I was nearly set up for a good 10k engine overhaul, sigh of relief when it was sorted with a 250b new plug...????????

 

 

 

[Denim]

Another possibility is water in the fuel system gradually built up through condensation which can be worse during the rainy season. Doesn't take much to make a problem. 

 

You could empty out all the fuel and remove the float chamber from the carburetor and clean and dry it. Before replacing check float for leaks ( should be empty with no fuel inside ) and make sure needle is clean , seating well and not sticking. Long time since I renovated a carburetor so not sure whether that last bit is still relevant. In any event , before reassembly make sure everything is dry by running an airline all over it.

 

Then try to restart with clean plug and fresh fuel.

 

Finally, a new battery might also help if you have had the old one a while. Not that expensive if it helps.

[Damrongsak]

14 hours ago, Denim said:

Lots of very short journeys at low speeds can lead to deposits in the engine. A few long runs at speed can burn this off.   ...

We used to call that an "Italian Tuneup".

[KeeTua]

19 hours ago, Kwasaki said:

I guess all you can do is keep an eye on it and carry a spare plug.

Not only lean but rich mixture with timing slightly out can cause plug fouling, I take its air-cooled so could be running too hot.

I'll keep a new spare under the seat but the situation is a nuisance for my wife and she threatens to buy a new bike sometimes which would be a waste considering how little use this one sees. Hopefully I'll get this problem sorted out. It is air cooled but rarely gets driven far enough for the engine to get too hot.

[KeeTua]

15 hours ago, Agusts said:

The colour of the electrode is the key if mixture problem, also next time try to clean the electrode and ground with a fine sandpaper when it goes bad (they say some fine build up , hard to see, weakens the spark), check and adjust the gap too...

 

They say Ohm meter check is useless but worth it in my opinion, must compare with another new/old plug, also check with it any leak from electrode to porcelain/ceramic part and the ground, should set it to KOhm to see any leak...

I just took another closer look at the old plug under a lamp using a magnifying glass and can see some deposits around the base of the center electrode like a small ridge. I'll check the plug for spark again and then give it a thorough cleaning and check for spark again. I checked with an Ohm meter too but didn't detect any leak to the porcelain insulator.

[KeeTua]

13 hours ago, Denim said:

Another possibility is water in the fuel system gradually built up through condensation which can be worse during the rainy season. Doesn't take much to make a problem. 

I did drain the float bowl by loosening the screw at the bottom and there were some very small blobs of moisture but I wasn't sure if it was coming from the drain line instead of the float bowl. As I mentioned above the fuel, fuel line and filter and carb were all recently replaced but undoubtedly there was still a little fuel left in the tank. The little blobs disappeared after draining for a while. I will definitely sort that out too. Maybe some moisture absorbing additive to the gas tank? The battery is 3 years old. I'll keep that lower on the list of things to work through.

[EricTh]

Just exchange your Honda Wave and  buy Honda Scoopy, I never had any problem with the plug.

 

It doesn't cost much and give you peace of mind.

Edited April 29, 2021 by EricTh

[KeeTua]

9 hours ago, EricTh said:

Just exchange your Honda Wave and  buy Honda Scoopy, I never had any problem with the plug.

 

It doesn't cost much and give you peace of mind.

With how little the old Wave gets ridden its hard to justify the cost of a new bike. Having an older beater has its advantages. We don't worry about leaving it out at night or worry about it when people borrow it. It doesn't have current registration or a license plate so people aren't interested in borrowing it to go into town on. If it was a new bike with good registration I think it would get ridden a lot and it wouldn't be me our my wife doing the riding.

[Kwasaki]

 

On 4/29/2021 at 7:05 PM, KeeTua said:

With how little the old Wave gets ridden its hard to justify the cost of

I'm in the process of getting my Oz mates Wave 125 going it's 17 years old. 

Out of interest did you get all you wave parts from a Honda dealership or did fine it better to get on-line.

[KeeTua]

18 hours ago, Kwasaki said:

Out of interest did you get all you wave parts from a Honda dealership or did fine it better to get on-line.

I bought the ignition parts from the local Honda dealership and the rest I bought via Shopee and Lazada trying to buy only OEM if possible. I don't care for our local dealership because they don't use the computer to print an invoice so they can charge what they like and if they need to order parts its slower to get them than me ordering online. I'll will avoid them in the future whenever possible.

 

2007 Honda Wave 100
Honda dealer (I think these OEM parts can be found online and cheaper):
CDI unit 30410-KRS-901 @ ฿550
Coil 30500-KRS-601 @ ฿550
Plug NGK C7HSA @ ฿80 (฿40 online)
Plug connector ฿80

 

Lazada/Shopee:
Carb 16100-KRS-971 @ ฿1300
Shocks front and rear @ ฿662
Tires front and rear @ ฿864
Inner tubes @ ฿126
Chain and sprockets @ ฿388
Kickstarter arm 28300-KTL-740 @ ฿114
Kickstarter rubber 28311-342-000 @ ฿27
Kickstand 50530-KPH-900 @ ฿100
Fuel line x 3m. and fuel filter and misc screws @ ฿177
Headlight bulbs x2 34901-KRS-901 12v 18/18w ฿80

Just over ฿5,000 in parts, not bad as I think it will buy many more years of use.

[Randell]

You have my admiration Kee Tua ,  good job. Its great to be able to fix up old things in this now throw away world.

[Orinoco]

On 4/29/2021 at 9:27 AM, EricTh said:

Just exchange your Honda Wave and  buy Honda Scoopy, I never had any problem with the plug.

 

It doesn't cost much and give you peace of mind.

A Scoopy is for girls. A Wave is for boys.

[canthai55]

All those flat floor scooters - good to ride when wearing a dress.

SIL bought a new Scoopy last year. Told her - as she wanted that style to get a Grand Filano.

But no. Took it for a ride - once.

[alacrity]

On 4/28/2021 at 5:22 PM, Agusts said:

I had a lot of advice about checking plugs, I can write a book about it...! lol

 

The colour of the electrode is the key if mixture problem, also next time try to clean the electrode and ground with a fine sandpaper when it goes bad (they say some fine build up , hard to see, weakens the spark), check and adjust the gap too...

 

They say Ohm meter check is useless but worth it in my opinion, must compare with another new/old plug, also check with it any leak from electrode to porcelain/ceramic part and the ground, should set it to KOhm to see any leak...(a mechanic had this but had no idea how to use it, so I took it and checked myself) !

 

I also checked the sparks against ground metal visually , then again they say a weak spark (red) or strong (blue) can not be quite identified, need high voltage apparatus to check exact spark real/correct power...

 

I hope you find the issue and it's not costly , it's amazing once it's resolved, great feeling, and you wonder how on earth I missed that  .....!!! ? I was nearly set up for a good 10k engine overhaul, sigh of relief when it was sorted with a 250b new plug...????????

 

 

 

Ignition systems after the coil are HT. So, doubt any multimeter test would be fruitful. A dielectric tester would be needed.

 

Given the price of a new plug, merely replacing with new would be the most effective check.

[alacrity]

On 4/29/2021 at 9:12 AM, KeeTua said:

I just took another closer look at the old plug under a lamp using a magnifying glass and can see some deposits around the base of the center electrode like a small ridge. I'll check the plug for spark again and then give it a thorough cleaning and check for spark again. I checked with an Ohm meter too but didn't detect any leak to the porcelain insulator.

Can you attach a (color) photo?

 

If you have checked the gap between terminals, what is it? New plugs are pre-gapped, but that integrity can easily be lost by a spurious mechanic, or 'cleaning' by others.

[papa al]

2 hours ago, canthai55 said:

All those flat floor scooters - good to ride when wearing a dress.

SIL bought a new Scoopy last year. Told her - as she wanted that style to get a Grand Filano.

But no. Took it for a ride - once.

You about dress size 14.?

 

She took it for a ride once then stopped using it.?

[KeeTua]

23 hours ago, alacrity said:

Can you attach a (color) photo?

 

If you have checked the gap between terminals, what is it? New plugs are pre-gapped, but that integrity can easily be lost by a spurious mechanic, or 'cleaning' by others.

I took the bike out for about an hour ride today and it ran sweet! Idles perfectly too. Hopefully tomorrow I'll get a chance to pull the plug out and see how it looks compared that last 'failed' plug and take some pics. I plan to give that failed plug a test too.

[KeeTua]

Today I pulled the current plug which was actually a used plug in the first place. I checked the spark with it grounded to the head and it looked normal and the color was a good deep tan, definitely not running too lean or too rich.

 

Next I connected the previously failed plug to check the spark and it would not spark at the the tip. I gave it a good cleaning with fine sandpaper and checked it again this time I saw the spark shooting off to the side from the electrode towards the threads. It refused to spark at the tip. That's the same behavior I observed when I first pulled that plug.

 

Checked the spark on a new plug ordered online, looked good and I installed it. I have two new plugs in standby. I drained fuel from the float bowl and no sign of moisture. First time around the other day there were signs of moisture. I realized today that moisture was coming from the thin aluminum bowl I was using to catch the fuel. Cool fluid hitting the warm bowl was creating condensation, switched to a plastic container and the fuel looked perfect.

 

I guess I'll just wait and see now. Take it out for more frequent longer rides as suggested above by Denim.

 

Good news is I finally figured out the correct sequence to get the fairings off for easy access to the engine and get them back on without getting frustrated. Actually I cheated and checked YouTube.

 

Picture of the plug I pulled out today that was running good. I couldn't get a good pic of the failed plug but it looked the same only a slightly darker color, not quite black. The gaps on the plugs were all correct 0.024-0.025"

Edited May 5, 2021 by KeeTua

[kickstart]

7 hours ago, KeeTua said:

Today I pulled the current plug which was actually a used plug in the first place. I checked the spark with it grounded to the head and it looked normal and the color was a good deep tan, definitely not running too lean or too rich.

 

Next I connected the previously failed plug to check the spark and it would not spark at the the tip. I gave it a good cleaning with fine sandpaper and checked it again this time I saw the spark shooting off to the side from the electrode towards the threads. It refused to spark at the tip. That's the same behavior I observed when I first pulled that plug.

 

Checked the spark on a new plug ordered online, looked good and I installed it. I have two new plugs in standby. I drained fuel from the float bowl and no sign of moisture. First time around the other day there were signs of moisture. I realized today that moisture was coming from the thin aluminum bowl I was using to catch the fuel. Cool fluid hitting the warm bowl was creating condensation, switched to a plastic container and the fuel looked perfect.

 

I guess I'll just wait and see now. Take it out for more frequent longer rides as suggested above by Denim.

 

Good news is I finally figured out the correct sequence to get the fairings off for easy access to the engine and get them back on without getting frustrated. Actually I cheated and checked YouTube.

 

Picture of the plug I pulled out today that was running good. I couldn't get a good pic of the failed plug but it looked the same only a slightly darker color, not quite black. The gaps on the plugs were all correct 0.024-0.025"

That still looks a bit black to me especially for a four stroke .

If you can ,try and get a compression  test done ,Google for the correct results ,I doubt if the guy doing the test will know .

Are you sure the engine is not using any oil .

I know it is a new carb , but what are the carb settings, try the pilot jet screwed out 1, 1/4-1, 1/2 turns ,check the height of the needle ,Google should tell you the correct settings for the carb .

A problem I have had with more than one engine , carb  float height that being wrong will not help .

Someone told me a long time ago ,the plug is at the end of the line ,look at things back from the plug .

[alx123]

That's a foul plug right there, it's either youre running rich or your piston ring needs changing. 

 

Maybe a simple carb tuning will help. 

Edited May 6, 2021 by alx123