Excessive 2-Stroke Smoke

My wife’s 50cc Going smokes a lot. Every mechanic just says “It’s normal”. It isn’t. I have a Dio which barely makes any, and my NSR, RZR, and other 50cc scoots of past didn’t smoke 1/10th the amount this going does.

So I took it in and said “fix it”. The swapped the muffler. Put in expensive oil. Adjusted the oil to the minimum setting. And swapped some kind of thing…errr…don’t know what. Like the injector…or valve…or oil door. Or whatever.

Anyway…after all that I can safely say it’s exactly the same. I can ride the scooter for a kilometer, stop, turn around and look back…and see a solid cloud of blue white smoke for the whole kilometer behind me.

So what do I tell them to do next? Rebuild the engine? Or perhaps the carb?

First thing I’d do would be get back any money they’d charged me.

Then bao fei it, and get another bike. you mad polluters you.

it may need new rings or a new cylinder or both. putting a new pipe on is not necessarily going to solve anything, as the oil smoke starts way before that

or maybe it’s just a cheap shitty engine design? I’ve noticed a lot of the mini 2 strokes tend to smoke badly. I mean, a two stroke SHOULD have smoke, but not excessively. how do you get the thing re-registered each year if it fails the HC part of the emissions test?

[quote=“urodacus”]Then bao fei it, and get another bike. you mad polluters you.

it may need new rings or a new cylinder or both. putting a new pipe on is not necessarily going to solve anything, as the oil smoke starts way before that

or maybe it’s just a cheap shitty engine design? I’ve noticed a lot of the mini 2 strokes tend to smoke badly. I mean, a two stroke SHOULD have smoke, but not excessively. how do you get the thing re-registered each year if it fails the HC part of the emissions test?[/quote]

It’s my wife’s. So I don’t know what she does with it. But I just put good money into rebuilding it. It looks better than brand new. I just need to fix the smoking. So comments like “get a new bike” aren’t what I’m looking for.

So you are saying I should rebuild the engine?

one way to get bad smoke is for oil to leak from the crankcase under compression into the chamber past the piston rings (i bet on that bike there is only one ring), this means either a new piston (with new rings) and cylinder hone, or just a complete new cylinder and piston together. You can do that yourself if you have the parts easily enough. don’t forget a new top and base gasket.

but maybe the oil metering into the cylinder is just stuffed: either always bad, or bad now from a jammed open oil pump, or maybe you have a choke that never closes on the carb. an old exhaust that is filled with oil residue may smoke a bit when it gets hot, or may block exhaust gas out and lead to over-rich running, but you say you just swapped it… so that’s not an issue here.

I’d have to agree on it being the piston rings, get them changed (possibly the head needs a re-bore if it’s damaged… or just replace the head piston and rings, it’s cheap enough).

One other thing, if your 2-stroke mix isn’t mixing right that could also cause smoke, you could try manually mixing your fuel and disconnecting the 2stroke oil pump (but to be honest this is way too much hassle).

The pump is new. Just talked with them. That was the “oil door thing” I mentioned before. So I’m taking it in for a new piston and cylinder. Cheap enough for a 50cc.

@Mordeth

I’m pretty sure from seeing some of your vids that you’re more of a rider than a fixer, but if you did want to try your hand at fixing that 2-stroke yourself, there’s a guy on youtube DioSpeedDemon who literally takes his Dio apart every once in a while piece by piece, he loves messing around with two stroke motors, and if you send him a request, he’ll show you exactly how to fix a specific problem (if his vids don’t already cover it). youtube.com/user/DIOSpeedDemon

He’s got his dio going about 113 km/h at the moment :wink: fun stuff

[quote=“SerpentChina”]@Mordeth

I’m pretty sure from seeing some of your vids that you’re more of a rider than a fixer, but if you did want to try your hand at fixing that 2-stroke yourself, there’s a guy on youtube DioSpeedDemon who literally takes his Dio apart every once in a while piece by piece, he loves messing around with two stroke motors, and if you send him a request, he’ll show you exactly how to fix a specific problem (if his vids don’t already cover it). youtube.com/user/DIOSpeedDemon

He’s got his dio going about 113 km/h at the moment :wink: fun stuff[/quote]

Cool. I can’t fix anything. I gave up trying. But I’ll check him out and send send a few hundred subscribers his way. Thanks for the tip.

You know the EPA is phasing out 2-stroke bikes, don’t you? I wouldn’t shell out too much money on any major “repairs” as time is most definitely not on your side.

Yeah, what you did to try and fix the problem won’t fix the smoke problem you have been having. I would say that your piston rings are bad. I recently fixed my 50cc with a stock piston and cylinder and it cost $2500nt total. I would just do that. If you know of anyone that can do the work for you, then it will be half that price.

People have been saying this for 10 years. So chances are in another 10 when it happens the bike will be crap again. So no worries.

Any strokers on the streets will be good for as long as they run. Don’t worry about scaremongering. A rebuild, Mordeth. Couple of grand and it’ll be good to go. Supervise, though (as if you didn’t know!)

Oh God!! Here we go again. What Sandman says it right. You can keep your 2-stroke as long as you live.

Hey Mordeath, I’ll buy that 50cc off you for $2500nt, :slight_smile:

Oh God!! Here we go again. What Sandman says it right. You can keep your 2-stroke as long as you live.

Hey Mordeath, I’ll buy that 50cc off you for $2500nt, :slight_smile:[/quote]

It’s all stock…but it’s sweet looking now. I’ll make a before after vid and put it in this thread. The piston looked fine…but it’s an eight year old engine…it had to be due for a rebuild. I used to take that 50cc across the 7 to Hualien with my wife and dog on it as well. Many years ago.

[quote=“Mordeth”]My wife’s 50cc Going smokes a lot. Every mechanic just says “It’s normal”. It isn’t. I have a Dio which barely makes any, and my NSR, RZR, and other 50cc scoots of past didn’t smoke 1/10th the amount this going does.

So I took it in and said “fix it”. The swapped the muffler. Put in expensive oil. Adjusted the oil to the minimum setting. And swapped some kind of thing…errr…don’t know what. Like the injector…or valve…or oil door. Or whatever.

Anyway…after all that I can safely say it’s exactly the same. I can ride the scooter for a kilometer, stop, turn around and look back…and see a solid cloud of blue white smoke for the whole kilometer behind me.

So what do I tell them to do next? Rebuild the engine? Or perhaps the carb?[/quote]

99% of the 2 strokes in taiwan that have this issue is due to piston rings.
buy a whole new top end for $3000nt and replace with the old one.
Might as well change the carb and exhaust too or at least rebuild the carb.

My RZR smokes a lot, and it seems to be drinking gearbox oil due to the crankshaft seal being knackered, allowing gearbox oil to be drawn in to the crankcase. (Redwagon gives a detailed explanation of it over on “my” RZR Revival? thread.)

Since the crankcase on a 2-stoke is part of the induction path, I don’t think its necessary that the rings be knackered in order for gear oil to get into the cylinder and (incompletely) burned.

I’ve never had a scooter and don’t know if a similar thing could happen to one. Obviously its a CVT automatic, but judging from the shelfspace devoted to gear oil at Tainan RT mart, scooters must use it somewhere?

Apologies for my scooter ignorance, but I guess someone who can write “My NSR, RZR, and other 50cc scoots of past” and also write “oil door. Or whatever.” (OIL DOOR!?) might be willing to cut me some slack. :smiley:

Why even have a 2 stroke these days? It’s environmentally irresponsible at best and just annoying as F*ck to everyone that has to ride behind you… 保費 is the best suggestion I’ve seen yet.

Because 2 strokes are awesome. And when well maintained they produce no visible smoke.

They gave me a new piston and cylinder. It’s still smoking. I’ll mention the CVT seal.

I’ve seen many more polluting four strokes in recent years than two strokes, but that statement is still simply not true.

For example, would it be more environmentally friendly to replace an old two stroke motor vehicle with a new one, when you rarely use your vehicle in the first place?

The answer is: Not necessarily likely; For want of a more specific answer. The cost of producing a modern full sized four stroke motor scooter for example can be large in terms of carbon emissions (if you believe in human carbon output as having a severe effect on the environment).
It is estimated that approximately ten percent of a vehicle’s emissions over a typical lifetime is actually produced when producing the vehicle in the first place. This is in simple carbon production. Plastics however consume and produce a much greater quantity of materials and emissions than metals such as steel. How much precisely would largely depend upon the style of production in the first place, and how much saved over a lifetime would really depend upon how the vehicle was operated and serviced.
If everyone with a motor vehicle in the world today were told to be more environmentally conscious and to purchase a much newer and less polluting car or motorcycle, you would quickly realise that the materials required to produce those vehicles would not readily be available. Furthermore, the cost of replacing vehicles frequently could further increase carbon and other emissions.

So far nobody as far as I understand has come up with a formula in regards to when and which motor vehicle to upgrade to in regards to pollution reduction as it is impossible to say with accuracy.

Anyone will admit that a traditional two stroke motor scooter will generally produce more emissions in terms of CO and CO2 than a four stroke equivalent. That is hardly a moral argument though for upgrading to a four stroke machine.
Firstly total average engine revolutions would produce a far clearer indicator of the advantages for upgrade, versus a newly produced four stroke machine.
Secondly four stroke scooters on a sliding scale are still far worse culprits than typical four stroke cars when comparing pollutant production in a single engine revolution cycle. This should at least cause a four stroke scooter user to question their own moral standing when it comes to typical pollution running cost production.

As far as I personally understand and agree however, a large number of two stroke motorcycles found on the roads produce a lot of unfavourable smoke. This I would like to see reduced.
However, two stroke scooters are now not allowed to be sold in Taiwan. It is unfair to force recent or even older purchasers of these vehicles however to simply give them up. And what then would gas bottles be delivered in? Its a social dilemma. If one has the ability to force these owners to surrender their vehicles, then what next? Anyone can find a justification for forcing their product onto whoever they deem a necessary purchaser. No! That will never do!

In the meantime however people can learn to be more responsible. People will and inevitably do learn to reduce their typical fuel consumption, and thus, their typical pollution production. This is regardless of what type of vehicle they own. The trend in bicycling recently is a good example of the growing conciousness that we need to do something to not simply reduce our fuel costs, but search for practical alternative transportation as the present system slowly clogs up to a halt. Building environmentally friendly public parks and amenities would mean that people would be encouraged to stay around their own area and perhaps not need to travel farther afield. Working from home also assists. I must say that personally since I moved to an area I find favourable, I travel far less frequently than I used to.

Indeed, once we start on this sort of “thou art holier than thee!” campaign there is quickly a realisation that nobody stands on the top of the holy tree.

Should I lecture others that they should all drive a Toyota Prius like me? Well I wouldn’t as its a ridiculous thing to say. Firstly I know what my car costs in terms of pollution production, and I’m nowhere close to the holiest branch on the tree. Secondly why would someone who drives a blue van need a Prius? Or why would someone who enjoys go carting or whizzing around mountain roads need a family sized hybrid? They would consume far less fuel if they purchased a performance vehicle, trust me on that one.

If you have ever heard the term “horses for courses” or the other way around, then you will know what I’m getting at here.

Being environmentally friendly is a personal choice. Its an education. Its a responsibility, yes.

What it shouldn’t become however is the next holy crusade. Everyone is entitled to what they can afford and what they believe they need for themselves.

What I believe to be most important however is educating individuals in how they can best achieve a level of satisfaction and matching their need whilst taking into account their responsibilities and respect towards others.

Old technology will die out, so you need not worry too much about it. Fortunately some people keep a little old tech on hand to remind the present where things and ideas are derived from. In fact some of the latest and greatest clean technology is a reinvention of the two stroke engine with differing forms of injection.