Cannot get HT to fire up

Rice Farmers 10 - Ireland 0

BSA said:

sounds like bad compression. The only other thing I can think of, you say your plugs wet so maybe your float level isnt set right and its flooding the engine.

BSA

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Thanks BSA, Bolts & Bikestin et al, The carb is a beauty and I'm not worried about the float level - I use the same needle setting on all HT carbs - either bottom groove or 2 bottom groove so the throttle opens really wide. The moist plugs is because it isn't firing up properly anfd fuel is unburnt I reckon.
The kill switch was eliminated way back now and is in fact deleted from the equation. The fuel and everything is good - head gasket, exhaust & intake gaskets all perfect. I has to be a piston ring. Nobody told me about that until I called the guy today.
I won't fix the rings cos I find it hard to get the piston to slide back into the cylinder barrel and I haven't got those ring tools.
I have failed to fix this bike but I have eliminated every possible cause and can only deduce that the low compression is cos of ring damage. I've run it down hills until the engine is really hot but it still can't keep firing when I reach the bottom. I've pushed this bike 500 metres back up the hill all day and I'm sick of it. I'll offer him a second hand HT 66CC ZBox motor which has new rings replaced after 350 kms during it's running in period and not used since. He can have it for 70% cost of a new one. I wasn't pleased when a ring went so soon and the motor hadn't ever exceeded 25 km\hr and for those who know me that happened just before I saw the light and went 4-stroke. This 48cc was a ZBox motor new in late January. I think these facts really tell us something about ZBox HTs. Warren, the owner of ZBox importers, wonders why I'm not buying any these days. I used to be a big buyer because I had no choice. It's been 2 days of wasted effort and I'm defeated - those rice farmers have reduced me to an angry broken wreck and I'm going into town to torch the chinese take-away. Thanks guys for all your help. It's a long while since I've been on the 2-stroke section of this forum and I've had a refresher course.

Irish, we know the HT has it's manufacture quality issues.
We know well the "quality fade" game is rife, another case was on the news again tonite on childrens toys.
Collectively we have to remain vigilant, but that don't mean to blame the entire distribution system on one case of a failed HT.
I don't think the HT in question on this thread failed, I think the cause of failure was neglect and or ignorance, or expecting it to do the impossible.

Bolts you could be right and you could be wrong. In this case I need to know if the owner has been riding it hard. I will find that out very soon via his mates and if he really was responsible then it is a faulty motor. I've had ZBox piston ring failure during running in and I really nurse those things during run in period. My point is from the ZBox engines I've had plenty are duds and a few (but less than the duds) were sweet from the start. That is a fact I found out from 6 motors - more if you include my friends wose ZBox motors I service.
Admittedly I got new rings gratis but it cost me to install them and they bust within 600 kms. They had a serious ring problems early last year. My experience with HTs has not been good and I am heartily sick and tired of always running in either a new engine or new rings cos I treat them almost the same as a new engine only for 300 kms not 500kms. Going about that sowly really does become painfull and I'm not going to speak well about the HT until I get one that goes 5000 kms without breaking. To make matters worse I have to read postings about going at 40 mph (yes mph not kph) for days on end which I'm expected to believe. Come on now I'm not that gullible.
About the time of the really serious HT problems there was a batch of chinese spokes on good quality brand name bikes that were snapping mid spoke all over the world. What was written in the good cycling magazines was the sordid truth about these spokes and all riders with wheels that were affected were told to take their wheels back to the shop of purchase for a free wheel respoke. That is what is lacking with the HT kit exporters - responsibilty to make good defective produce with a product recall like Merida, Cervello, Mongoose all did with the shonky spoke episode in 2006/2007. What use are 2 piston rings in the post when those are the same brittle rings that broke first time around. It's not OK Bolts and it is dishonest to pretend HTs are sort of OK most of the time when they plainly are not. That's my beef with HTs but thankyou for all the help and I'm sorry that I only found out today the the owner heard a pinging sort of bang before the motor misfired and then died. People take them to me when they are desperate cos they think I can fix anything which i can't always do. I only wanted to help the guy cos he's doing things tough. If I'd fixed it I'd maybe have asked him for $25 towards parts but not labour.
Theday I see an HT exporter do a product recall is the day I'll eat those busted HTs lying out there in my garden.

Hmm, well I don't know Irish, the failures you say about the HT is ofcourse expected, but I seem to have avoided anything as near as similar, infact nowhere near that extreme. But yes, some owners have approached me with their engines and it's issues and breakdowns, and all of them, it seems the root cause was owner related ignorance. For example, not understanding the cylinders are flash chrome.

I know of one owner who knows zilch about engines etc, but follows a bike builder's directions, maintenace and oil mix procedures to a T and over 2 years has not had any major problems.

On my own HT for personal use, I don't care about, "faster and fastest", I'm just happy to cruise, but respect the mechanics and where the cultre in China are at. They are not "at" the Le-Mans or Grand Prix level,
yet, or maybe never.Therefore they can never expect to "go back to drawing boards" and try to win the next race. That is why major motor race events are sponsored my major manufacturers. Honda for example, are out there at the race tracks competing, and that type of research is passed on to quality retail. Where are the Chinese ?

Thier race it seems at this point in time is a differant race to our Western thinking cultre.
So I lower my expectations, therefore I myself have had none of these severe problems.

Bolts, I ditched that 48cc motor and am instyalling a new 70cc with 400 kms on it or probably less. It got new rings last Feb and I never used it since because I lost confidence in it. I seem to lose confidence in so many of them but occasionally I get an OK one. What gets me is I treat them so well and break them in slowly and even after that I stop every 15 -20 mins for smoke to let them cool down. When running I change speed a lot so as not to strain them only going fast for very short bursts and then back down to about 30 kph which isn't fast.
Honda have really proved themselves in racing and that is why when the going gets tough economically they pull out of it. Like they did recently in Formula 1 and like they did back in Hailwood's day with their motorbikes. Mind you they paid Hailwood for about 10 years not to race for anyone else.
I wish Honda would get around to building a bicycle engine specially for what we need and my guess is they probably will.
It'samazing how far a 48cc HT travels through the air when you throw it from my workshop into the bush at the bottom of my hill. They really are an aerodynamic little motor.

Irish John said:

Bolts, I ditched that 48cc motor and am instyalling a new 70cc with 400 kms on it or probably less.:

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You gave up?
Admitted defeat?
Never figured out what was wrong with it?

I had a mystery motor failure the other day
Ask the customer what were the last things they did to it before it stopped working
It turns out my customer made a new exhaust gasket and forgot to cut the hole.....but denied it when questioned and it was too obvious to check...

I mean, how could anyone be that stupid?

Everything tested fine but it didn't even sound like it wanted to start

Moral of the story: don't smoke dope when you make gaskets

Irish John said:

It'samazing how far a 48cc HT travels through the air when you throw it from my workshop into the bush at the bottom of my hill. They really are an aerodynamic little motor.

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Who are you kidding?
they are as aerodynamic as a rock

Forbisher that's really funny about the exhaust gasket. How could anyone be so silly but they are. Reminds me of when the Irish invented the sit down toilet seat and then the English went and cut the hole in it. Trust the English to spoil a really good idea!
The ring(s) have blown which was established over 2 or 3 days by geniouses at MBc acting through myself as a medium.
Tomorrow I'll pull the cylinder barrel off and look at the rings but a 48cc shouldn't be able to be turned over by turning the pedals by hand when the bike is up on a workstand. I mean you can turn over a motor that way but not easily and continuously so the compression is gone and that is why the fuel wasn't being burnt and why it wouldn't stay firing at the bottom of the hill. I'm sorry I wasted people's time but the turkey who owns it didn't tell me that be heard a pinging bang before it started misfiring and then not firing. The owner actually delivered it to me through another person so that didn't help things but we were able to establish the cause by deduction and experimentation.
I'm still laughing at your gasket story Forbisher it's a corker. I suppose it's no sillier than what I did recently when I bought a chocolate ice cream, walked out of the shop, unwrapped it in the street and threw the choc ice into a bin and stuck the wrapper in my mouth. When I went to retrieve the choc ice from the bin it was all covered with unmentionable filth so I had to leave it there.

Irish, I am not sure if they still make this special, "patch" for suspected broken rings, but it was called "blue compression", I am not sure who made either, no one has heard of it recently. Some mechanics and auto electricians swore by it. As an apprentice I was sent to get some for the mechanic who had problems trying to get a V12 E-type Jag to fire up.
So I went and got this "blue compression", sealed in a brown paper bag.
As far as I know. the Jag fired up, but I miised how it was used cos the kettle boiled and had to rush out and make the coffee. But yeah, ask ya local parts store if they still stock a product called "blue compression"...give that try.

BoltsMissing said:

Irish, I am not sure if they still make this special, "patch" for suspected broken rings, but it was called "blue compression", I am not sure who made either, no one has heard of it recently. Some mechanics and auto electricians swore by it. As an apprentice I was sent to get some for the mechanic who had problems trying to get a V12 E-type Jag to fire up.
So I went and got this "blue compression", sealed in a brown paper bag.
As far as I know. the Jag fired up, but I miised how it was used cos the kettle boiled and had to rush out and make the coffee. But yeah, ask ya local parts store if they still stock a product called "blue compression"...give that try.

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Well stone the crows Bolts, it is so long since I've heard of that stuff that I'd completely forgotten about it ever having existed although it was once as popular as Cream of Tartar (don't hear that being mentioned much these days either). My mate Norm down the road fixes vintage sports cars and I rode down to ask him if he had any. Sure enough there on a shelf in the depths of his cluttered workshop was 2 packets of it. When he showed me it it all came flooding back - like finding an Aussie ten shilling note in an old suit pocket - I just stared at it, The waxed brown paper packet still sealed and as good as the day it was bought - Genuine Blue Compression Powder made by Obadiah Ackroyd & Sons, Pontefract, Yorks. It was like going on holiday to some exotic place I've never been before like Marakesh and bumping into my long dead Granny. I recognised it so well but the brain couldn't call it up into my consciousness - what a weird feeling.
He said I could have the packet cos he had another one. I was ecstatic and thanked him and tore back home to my workshop. I knew how to apply Blue Compression because I remember being told by some old fart in a pub who had been a boilermaker in the Belfast shipyards and they used it on big steam turbines to stop leaks in inaccessible places in ships engines.
I opened the packet carefully because I wanted to keep the wrapping and frame it. The rich blue and gold lettering is really beautiful even it was a bit faded.
At last I'd been saved from the ignominy of having to tell my friend that his engine was cactus and I couldn't fix it. I was so grateful to you especially Bolts and feeling so proud of the knowledge base of MBc and the benefits of membership etc.
I started taking the head off the HT and readying the top of the piston for application. I was using my plug gap feeler guage cos it is just the most perfect tool for applying the compound. (0.o5mm is the perfect applicator blade on the guage BTW)
I swivelled around on my work stool to the bench behind where the bag of Blue Compression was and, to my utter horror and dismay, the packet was there but the Blue Compression was gone. I looked like a stunned mullet - no kidding. All that was left of Obadiah Ackroyd & Sons powder was a grey residue about 2 microns thick. I wept with grief probably at the embarassment of having already excitedly phoned the bikes owner to tell him I had solved the compression problem more than at the disappearance of the powder itself.
I tore back to the vintage sports car workshop to tell Norm what had happened. He had a wry smile on his face and said " Sorry John, I should have warned you to use it immediately after opening." He then went on to tell me how he opened a bottle of 150 year old Aussie claret that he'd bought at auction for $3000 only to see it oxidise in front of his eyes as he proudly admired it and smelt its aroma. Well my packet of Genuine Blue Compression had cost me nothing and out of respect for the loss of Norm's $3000 bottle of Grange Hermitage Claret I didn't think it was right to complain. What a day it has been Bolts but at least I still have that packet with the lovely lettering and a picture of an old brick factory in Pontefract. It's a nice memento to have I suppose.
I'll post a picture of the wrapper if you're interested.

yeah, that's right Irish, brown bag was waxed as I recall, was 1975 at the time. And now as I remember, was warned to be carefull to not open the bag till ready for use. That makes sense now, the kettle was boiling, ( no auto off in them days, too much of a luxary) and had to rush out to turn it off, then that makes perfect sense, the mechanic had to use it straight away. Gee thanks I Irish, often wondered why they all panicked.
Turned out though, the Jag still did not fire up again, was out of fuel after all. I did try to tell them the gauge showed low when I drove it back after dropping off the customer, ( customer service back then, but took the long way, hey, E-Type V12 Jag, who would'nt ? ) but no one listens to an apprentice, just make the coffee, be told and get some more of that Blue Compression.