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Old 06-19-2024, 12:58 AM   #1
tt250vabeach   tt250vabeach is offline
 
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Is it weird to need throttle to start? But runs beautifully Hawkeye 150

G'day

I have a Icebear Hawkeye 150 GY6, and while I haven't messed with the jetting at all I have done an ecr block and emissions removal also the usual like valves, spark plug oil etc

I have a stock, drop in mikuni clone carb from gy6racing I simply dropped in, and it runs perfectly. I'm at sea level, from idle to wide open it runs smoothly and flawlessly with no weird noises or hiccups.

However to start it, it will never start from just the electric starter if it's not already warmed up, I HAVE to give it throttle, and then it'll start and run with no throttle and idle beautifully.

Is this normal or is my carb actually something to fix

Thanks


 
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Old 06-19-2024, 07:13 AM   #2
Thumper   Thumper is offline
 
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Does that gy6racing carb have the enrichment "choke" circuit? I see a black button to lift on a photo of the carb.

I would think using that choke would be the normal cold start method if you have it. Many bikes will NOT start when cold if you twist the throttle with no choke since it opens up air when less air/more gas is needed when cold.
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Old 06-19-2024, 08:34 AM   #3
tt250vabeach   tt250vabeach is offline
 
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Quote:
Originally Posted by Thumper View Post
Does that gy6racing carb have the enrichment "choke" circuit? I see a black button to lift on a photo of the carb.

I would think using that choke would be the normal cold start method if you have it. Many bikes will NOT start when cold if you twist the throttle with no choke since it opens up air when less air/more gas is needed when cold.
It does not have a manual choke, it has an "electric choke".

Thanks, and sorry if my question is silly


 
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Old 06-19-2024, 09:29 AM   #4
Thumper   Thumper is offline
 
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Oh. I think I found it (a CV carb, vacuum operated, called PD24 CVK). I see, it does have an electric choke!

My guess is that it is normal for that carb to need a throttle twist to start.

If you haven't looked into it, your throttle opens a butterfly valve in the throat of the carb, exposing the carb to the vacuum generated by intake valve opening. The vacuum is vented to the cap over the diaphragm that is connected to the slide-which pulls the slide up. These carbs were common on lots of multi-cylinder Japanese bikes, like the GS series (except the first few years which had direct slide type carbs).

This is very different than the typical direct slide control carbs on the dual sports which lift the slide with the cable.

CV carbs don't open more than the engine needs, which you can easily do with a direct cabled slide. It is easier for the manufacturer to set it up and tune it to get the right amount and mixture of fuel/air. Nifty device.
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-NOS 2020 KTM 250SX (2-stroke motocross), less than 10 hours on it


 
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Old 06-19-2024, 11:07 PM   #5
tt250vabeach   tt250vabeach is offline
 
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Quote:
Originally Posted by Thumper View Post
Oh. I think I found it (a CV carb, vacuum operated, called PD24 CVK). I see, it does have an electric choke!

My guess is that it is normal for that carb to need a throttle twist to start.

If you haven't looked into it, your throttle opens a butterfly valve in the throat of the carb, exposing the carb to the vacuum generated by intake valve opening. The vacuum is vented to the cap over the diaphragm that is connected to the slide-which pulls the slide up. These carbs were common on lots of multi-cylinder Japanese bikes, like the GS series (except the first few years which had direct slide type carbs).

This is very different than the typical direct slide control carbs on the dual sports which lift the slide with the cable.

CV carbs don't open more than the engine needs, which you can easily do with a direct cabled slide. It is easier for the manufacturer to set it up and tune it to get the right amount and mixture of fuel/air. Nifty device.
Thank you for the info! And the detailed explanation. I feel better!


 
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