Diaphragm on side of Carb???

JGunn · 08-30-2018, 12:36 AM

Does anybody know what the diaphragm on the side of the carb is for? I'm curious if this is the culprit for my idling problem. I've heard it called the air enricher. I talked to another guy on this site and he said he was able to bypass it and his bike idled fine after he did it. I'm having some idling problems when I first start my bike and for the first 5 miles or so. I pretty much have to blip my throttle to keep the bike on. Yes I cleaned the carb and everything checks out but I have no idea what this side valve thingy is and if it's working properly. it has a spring and two screws.

Donald McPherson · 08-30-2018, 04:36 AM

OK I know my bikes a 125cc but I have just ordered a cheap clone heavy duty carb. Going with reports I am told will cure my erattic revvs at idle and will give me better performance. Best of all it's only £31.00

Vegas Street Rider · 08-30-2018, 11:41 AM

Your bike could be running too lean and hence the idle problems. You might need to adjust the valves. There is a good how- to here on the site. These bikes do tend to be a little cold blooded though. Engage your choke when first starting it and then slowly disengage it as the idle speeds up until it runs on it's own. Should only take a minute or two. Now that it is warm, set the idle with the idle adjustment screw to about 1500 rpm. I did mine just by ear until I had a strong steady idle.

JGunn · 08-30-2018, 04:46 PM

Interesting. I'm trying to get the bike ready to sell otherwise I might've done what you are doing. Would you mind giving me the website where you found this carb? Thanks

JGunn · 08-30-2018, 04:49 PM

Thanks Vegas Street rider. I've done what you're talking about. I just didn't want to have to write it down. I've adjusted the pilot screw as well. No go. I'm really trying to find out what that side valve is for.

Donald McPherson · 08-31-2018, 02:45 PM

That's mycheap carb intalled. Seems a bit nippier and now I get 5pmh more taking me to 65mph. Has also sorted out my erratic tickover.

08-30-2018, 11:41 AM	#3
Vegas Street Rider Senior Member Join Date: May 2015 Location: Henderson, NV Posts: 1,089	Your bike could be running too lean and hence the idle problems. You might need to adjust the valves. There is a good how- to here on the site. These bikes do tend to be a little cold blooded though. Engage your choke when first starting it and then slowly disengage it as the idle speeds up until it runs on it's own. Should only take a minute or two. Now that it is warm, set the idle with the idle adjustment screw to about 1500 rpm. I did mine just by ear until I had a strong steady idle. Login or Register to Remove Ads
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08-30-2018, 04:49 PM	#5
JGunn Junior Member Join Date: Jun 2018 Posts: 18	Thanks Vegas Street rider. I've done what you're talking about. I just didn't want to have to write it down. I've adjusted the pilot screw as well. No go. I'm really trying to find out what that side valve is for. Login or Register to Remove Ads
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08-30-2018, 04:36 AM	#2
Donald McPherson Member Join Date: Aug 2018 Location: Aberdeen Scotland Posts: 47	OK I know my bikes a 125cc but I have just ordered a cheap clone heavy duty carb. Going with reports I am told will cure my erattic revvs at idle and will give me better performance. Best of all it's only £31.00
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08-30-2018, 04:46 PM	#4
JGunn Junior Member Join Date: Jun 2018 Posts: 18	Interesting. I'm trying to get the bike ready to sell otherwise I might've done what you are doing. Would you mind giving me the website where you found this carb? Thanks
	0

08-31-2018, 02:45 PM	#6
Donald McPherson Member Join Date: Aug 2018 Location: Aberdeen Scotland Posts: 47	That's mycheap carb intalled. Seems a bit nippier and now I get 5pmh more taking me to 65mph. Has also sorted out my erratic tickover.
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