Petro
Scoot Enthusiast
Posts: 149
Location: Gothenburg, Sweden.
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Post by Petro on Aug 18, 2020 14:04:50 GMT -5
I found both yes and no in my search, some say there is a limiter @ 9k rpm, others @ 10k... And others that there is none at all...
What's your experience, I am trying to get my motor to rev out but despite light rollers, bigger/smaller jet the top rpm's wont increase, not even if I rest my nose on the tachometer @ 50mph...
On the stand it's the same, 18mm or 24mm carb gives the same rpm...
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Post by CrankingWithCG on Aug 19, 2020 3:19:39 GMT -5
Check your cdi box and the plug. All cdi have 6 plug ports, but a lot of scooters only have 5 wires on the plug with one blank slot. I guess they stopped installing the rev limiters electronically in favor of transmission and fuel regulations
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Petro
Scoot Enthusiast
Posts: 149
Location: Gothenburg, Sweden.
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Post by Petro on Aug 19, 2020 7:41:54 GMT -5
Check your cdi box and the plug. All cdi have 6 plug ports, but a lot of scooters only have 5 wires on the plug with one blank slot. I guess they stopped installing the rev limiters electronically in favor of transmission and fuel regulations Mine also have 6, the one that limits the scooter to 30mph I already have disconnected with a switch. I am talking about up top after say 9k rpm, if there is like a inbuilt limiter in the stock CDI, like an engine protection? I guess I have to take the belt out and rev it on the stand to see for my self. I remember my cheap chinese EFI scooter reving more but that kit came with its own CDI. |
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Post by CrankingWithCG on Aug 19, 2020 18:25:34 GMT -5
Most 50cc GY6s cap off at around 9 to 10 grand due to valve float if I had to guess, or port limiting
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Post by GrumpyUnk on Aug 20, 2020 10:03:49 GMT -5
Nine or ten grand is about one or two thousand too many if you want any sort of engine life. Personal opinion.
Actually, I have a wrap around the plug wire style tach pasted to the handlebars. The engine, again, IMO, seems to run best when it is below 8k. Much beyond and all you are doing is spinning way past the torque peak. IMO.
Have fun.
tom
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Petro
Scoot Enthusiast
Posts: 149
Location: Gothenburg, Sweden.
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Post by Petro on Aug 20, 2020 11:56:38 GMT -5
Nine or ten grand is about one or two thousand too many if you want any sort of engine life. Personal opinion. Actually, I have a wrap around the plug wire style tach pasted to the handlebars. The engine, again, IMO, seems to run best when it is below 8k. Much beyond and all you are doing is spinning way past the torque peak. IMO. Have fun. tom I run mine around 7k, always, its just that I do some "testing testing" and I am confused that I cant make it "break up" as I could with my other scooters (with aftermarket EFI)... I've grown apart from carburettors and I find it hard (and boring) to get the right settings for both torque and top end... The 24mm gives me good torque but the consumption is way over limit at my 40 mph average speed. I have a Naraku 20mm sent to me, my 18 and 24mm are nonames and I had my share of headache with that before... Also a Naraku CDI is on incoming but I do not (really) think that the CDI is the reason. I am thinking that maybe the exhaust causing it but that too, I never upgraded it on my other scooters and they would rev out just fine with the same cylinder/head... I guess I have to much time in my hands...  |
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Petro
Scoot Enthusiast
Posts: 149
Location: Gothenburg, Sweden.
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Post by Petro on Aug 30, 2020 0:30:58 GMT -5
After a lot of thinking I decaded to change the rocker arm assy. The complete spare one I had was also for 64mm valves but the angle of attack on the adjustment screws seemed different than the stock. Now it revs as it should and even the bottom torque is better, one can even hear it. If I had to guess, I'd say that the stock one wasn't 64 nor 69mm but something in between... The 20mm Naraku carb mentioned above turned out to be an 18mm and is on it's way back to the seller... I bought another cheap 24mm which I am going to modify (with a blunt axe  ) for efficient mph. If that doesn't work I'm taking the step towards an aftermarket cheap EFI like I had on my other scooters. Thank You. EDIT: Thanks to bigbeastgy6 with Your post above that pointed me in the right direction!  |
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Post by GrumpyUnk on Aug 30, 2020 10:39:16 GMT -5
Who makes a cheap aftermarket EFI? Perhaps only available in the EU?
You may find a 24mm is too much carb, and you don't get good operation as it will not 'pull' enough airflow to get into efficient mixing of fuel and air. It could also end up running in the 'intermediate' fuel circuit, rather than the 'main' high speed circuit.
tom
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Post by mikehailwood on Aug 30, 2020 11:39:49 GMT -5
I too am curious about the availability of an aftermarket EFI for a GY6 50.
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Post by GrumpyUnk on Aug 31, 2020 8:08:41 GMT -5
If you don't mind spending the moolah, a Honda Metro as EFI. When, not if, the China mimics get one to take apart and reverse-engineer, they'll put them on the market. The Sanyang Classic (Wolf? Bear?) 150 single sold in Taiwan and other FE markets has EFI. I suspect they are not the only ones in that size and price range.
What EFI requires parts wise are few. pump, injector, O2 sensor, load(maf/map) sensor, brainbox to do the math and control the squirter.
There are parts available on aliexpress or alibaba. I saw complete setups(I think), aftermarket, but they were in the $300 range. All the machines I have were purchased broken, disabled, abused, or 'tuned' by ignorant persons who thought the ductwork was unnecessary. I have not paid more than $175, so have no interest in a system costing double the machine. It would be fun to fiddle, but not that pressing to me.
tom
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Petro
Scoot Enthusiast
Posts: 149
Location: Gothenburg, Sweden.
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Post by Petro on Aug 31, 2020 12:37:42 GMT -5
The EFI kit I bought like 4 years ago was €120 from china, cant find it anywhere now... It had a sensor I welded on the exhaust, a solenoid acting as a pump and a black box (the brains of the operation). All this fitted on an intake (24mm). Also came with a CDI, hoses, clips and a wiring harness. I obliviously had a carb with me as replacement for I didn't trust that solenoid @2-3k jumping up and down to make petrol pressure for the injector. But this kit never gave me any headache at all, despite weather. I gave that scooter away to a kid in Germany so long gone is the lot... Here is one kit, www.aliexpress.com/item/32786077851.html , there is cheaper ones but still, all of them way to expensive these days in my opinion... Edit: About the 24mm carb I ordered, I am going to downsize it to 21mm I think. |
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Post by CrankingWithCG on Aug 31, 2020 12:56:18 GMT -5
The EFI kit I bought like 4 years ago was €120 from china, cant find it anywhere now... It had a sensor I welded on the exhaust, a solenoid acting as a pump and a black box (the brains of the operation). All this fitted on an intake (24mm). Also came with a CDI, hoses, clips and a wiring harness. I obliviously had a carb with me as replacement for I didn't trust that solenoid @2-3k jumping up and down to make petrol pressure for the injector. But this kit never gave me any headache at all, despite weather. I gave that scooter away to a kid in Germany so long gone is the lot... Here is one kit, www.aliexpress.com/item/32786077851.html , there is cheaper ones but still, all of them way to expensive these days in my opinion... Edit: About the 24mm carb I ordered, I am going to downsize it to 21mm I think. You want something snappy, try to find a mini 21mm flat slide. Oko or something like that. Youd have to swap throttle cables, but they're nice carbs. Manual choke, but the throttle response is soooo good on the slide carbs |
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Post by jaxe on Mar 10, 2021 21:07:09 GMT -5
I found both yes and no in my search, some say there is a limiter @ 9k rpm, others @ 10k... And others that there is none at all... What's your experience, I am trying to get my motor to rev out but despite light rollers, bigger/smaller jet the top rpm's wont increase, not even if I rest my nose on the tachometer @ 50mph... On the stand it's the same, 18mm or 24mm carb gives the same rpm... |
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Post by jaxe on Mar 10, 2021 21:08:38 GMT -5
Hello Hello. CAn you tell me which wire on the cdi (NCH 50 Metro) as the limier wwire? Many thanks
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) for efficient mph. If that doesn't work I'm taking the step towards an aftermarket cheap EFI like I had on my other scooters.
