What mechanical issues cause a scooter to fail the smog check? What parts/service are needed to make it pass?
Forgetting to ask the testing guy to leave the probe hanging out of the exhaust. Nobody fails the smog check.
If yours does, the basic reason is because the engine is running with the wrong fuel mixture, or is burning oil. It could be the air filter or the exhaust itself is blocked, or the carburettor is out of adjustment. Expensive new parts rarely required.
Or it may just be general engine wear, which is not easy to fix. New piston rings might do the job, but if your scooter is ancient and it’s obviously belching out fumes, you might as well just chuck it away and get a new one. Two-strokes are supposed to burn oil anyway, but as the engine wears (which happens somewhat more quickly than with 4-strokes, because lubrication is not so effective) they burn more, producing clouds of smoke. A 4-stroke will do the same, of course, but it generally takes longer to get to that state.
Anyway, the mechanic should first check and adjust the obvious bits, unless it’s quite clear your engine is knackered (say, if you’ve got 150km on the clock).
I never deal with that crap. All my scooters and motorcycles have been modified. The shop I take my scooter too gets it to pass for me free of charge. I take my motorcycles to him too (even though he doesn’t work on my motorcycles) and he helps me for free as well. Most mechanics can help you with this process. Look at all the modded out scooters and motorcycles on the road, do you think they all pass. No way!
Does modding a motorcycle or scooter make its pollutant emissions go up? Just wondering why they would be less likely to pass.
You don’t fail due to emissions, you fail due to not having all the original equipment on the bike. [corrected - this is only when you transfer ownership and not during emissions] This is one of those shortsighted rules that might make sense from a certain viewpoint while completely ignoring the real world effect.
You don’t fail due to emissions, you fail due to not having all the original equipment on the bike. This is one of those shortsighted rules that might make sense from a certain viewpoint while completely ignoring the real world effect.[/quote]
I thought:-
(a) The emissions test was just that, and they ignored everything else.
(b) The only time modifications were an issue (assuming they don’t affect emissions, which some performance mods might, for example, by running richer) was on the ownership transfer inspection, when everything has to be stock and original.
Am I wrong (again?)
My scooter hasn’t passes the test in years. My scooter guy will usually do the check first, see that it fails, then get a second probe and for my exhaust, then hook the one connected to the computer up to one of their new scooters. I’d really like them to fix the cause of this but every time I go there they tell me “Nevermind. It’s too much trouble. Next time, next time”
You’re right, the emissions test is only just that. The person who does the test doesn’t care what you’ve done to your vehicle. It’s not like the testers are employees from the department of motor-vehicles,
so they certainly won’t say or do anything other than run the test. Well, as it was mentioned before, the tester may help you pass your test if you fail.
Also you’re right about modifications are only an issue when you want to transfer ownership. I don’t know how far they’ll go to check to see if your scooter/motorcycle is stock or not. I’ve been told by
one Taiwanese mechanic that the inspection is not too thorough. They just compare your vehicle to a picture and if it looks the same, it passes. I can’t say I know for sure, as I’ve never done it myself.
However, I do know that at least one modification will definitely affect emissions and that’s removing the EGR (Exhaust Gas Recirculation). Most scooters/motorcycles in Taiwan have these. I know my
6 year old scooter does for example, and I’ve seen it on a Hartford Mini and on those new Quannon motorcycles.
I have upgraded to bigger carbs on all my scooters and motorcycles and yes this does affect the emissions. Also if you have changed to an aftermarket exhaust or bored and stoked your engine can affect it as well.
Yes, this is SOP in Taiwan. How else do you think people get away with driving those 30-year-old contraptions belching vast clouds of smoke, OP? If you want to take this route (rather than being socially responsible) you just need to find the “right” garage.
[quote=“Ducked”]
I thought:-
(a) The emissions test was just that, and they ignored everything else.
(b) The only time modifications were an issue (assuming they don’t affect emissions, which some performance mods might, for example, by running richer) was on the ownership transfer inspection, when everything has to be stock and original.
Am I wrong (again?)[/quote]
I think you’re right and corrected my post. I don’t bother with any modifications on my bike (hartford 150) because I don’t really care enough about better performance or looks. And I’ve never done an emissions test on my motorcycle in Taiwan. I guess my mechanic does it because I’m able to renew my registration and insurance every year.
I mentioned one kind of emission control, but it really wasn’t the one I was thinking of. The EEC (Evaporated Emissions Control) if disabled will definitely make your CO count go up, as I’ve seen it on the emissions test machine.
When it was disabled, I saw my CO count go up from around 1.7 to over 3.0.
I really don’t like the EEC very much, if the vacuum pump is broken it can and will affect how well your scooter runs. I found this out when I went to my friend’s shop and I wanted help in tuning my carburetor as I didn’t have
a tool to count my rpms accurately. When he was helping me tune my carburetor, he hooked up my scooter to the emissions test machine and didn’t like the readings. Then he tested the vacuum pump to see if it held pressure
and found that it didn’t. After replacing the vacuum pump, the emissions went down.
I also found out recently that the pilot screw (this helps control how much fuel is used at idle and above idle speeds) setting in my English scooter manual and the Taiwanese scooter manual for my scooter are different. In
my English manual, it says 2 1/2 + or - 1/2 and in the Taiwanese manual it says 2 + or - 1/2. Why are they different? Well, in my English manual it doesn’t have the EEC listed in it to explain how to troubleshoot/fix it. In
the Taiwanese manual it does.
Here’s a link that looks like it comes from an English service manual that describes how to troubleshoot/fix problems with the EEC
Gonna necro this thread.
My scooter used to have great emissions results. I went away for 6 months and left it parked, and stupidly saw a garage a few minutes away and drove it straight there… and promptly failed.
I’m guessing as it was sitting there that long things got gunked up. I plan to drive it Taichung to Taipei tonight so I figure that should remove some deposits.
The mechanic warned me that I need to get it checked within 30 days again and he said if it fails twice I am forced to make repairs before they will test it again. He didn’t offer to fake a test for me. I should have offered him some cash.
He then started advising of various costly repairs of course.