Can't figure out carb adjustment

hnkrader

hnkrader

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Joined
Mar 16, 2025
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Indiana
Hell all, so I'm new to carburator adjustment and for the life of me I cAn figure out how to get this thing running right. I've got a 1971 CL175. I did a carb clean and rebuild, points gap adjustment, timing adjustment, and valve lash adjustment earlier this month. After doing all this, I've finally had time to get the bikes carbs adjusted and ready to ride. Well no matter what video/manual I look at, I just can't figure out why mine refuses to work right. I've refer to this post most recently (I'll link a image below) but it still doesn't feel right. My idle doesn't raise one but when I mess with the idle air mixture screws on my carbs. It's like they don't even do anything when I try to adjust them to make the idle idle as high as possible, to then bring it down. Any help would be appreciated, as I don't 100% know what I'm doing. Thanks

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ancientdad said:
Typically when the idle mixture adjustment screws are ineffective, it means the cabr passages or pilot jet emulsion holes are not fully clean.
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The bike also kinda backfires and sputters when I hold the throttle just slightly open, what could be causing that. What I mean is I just sit there with the throttle slightly open and it hesitates, sputters, and will sometimes backfire
 
ancientdad said:
Stock air filters or pods?
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Stock air filters, I rebuilt the carbs with those guys in Houston carb rebuild kits. I saw my main jets were #90, so I replaced them with the #90 from the kit. The included pilot jet was a #35
 
hnkrader said:
Stock air filters, I rebuilt the carbs with those guys in Houston carb rebuild kits. I saw my main jets were #90, so I replaced them with the #90 from the kit. The included pilot jet was a #35
Click to expand...
Unfortunately, no matter where you buy carb kits it's never advisable to use the brass parts and float needles from them. They're typically incorrectly-sized and it goes for all kits sold out there. It's a known problem to everyone who has used a carb kit before, but those who haven't often buy them without realizing. Generally only the gaskets and o-rings are usable in the carb kits currently available. Here's an article about some of it.

 
ancientdad said:
Unfortunately, no matter where you buy carb kits it's never advisable to use the brass parts and float needles from them. They're typically incorrectly-sized and it goes for all kits sold out there. It's a known problem to everyone who has used a carb kit before, but those who haven't often buy them without realizing. Generally only the gaskets and o-rings are usable in the carb kits currently available. Here's an article about some of it.

Click to expand...
So then what do you advice that I do? I know I haven't vacum tested the float needles, but I'd did check for sealing by holding the carb upside down and blowing air through the fuel inlet. I didn't hear any air coming through. The kit has good reviews and it seems like the best one. I get nothing is better than OEM, but it's definitely discouraging to hear that I basically wasted 60 dollars on something viewed as a waste of money.
 
hnkrader said:
So then what do you advice that I do? I know I haven't vacum tested the float needles, but I'd did check for sealing by holding the carb upside down and blowing air through the fuel inlet. I didn't hear any air coming through. The kit has good reviews and it seems like the best one. I get nothing is better than OEM, but it's definitely discouraging to hear that I basically wasted 60 dollars on something viewed as a waste of money.
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Did you save the old brass? Needles and jets? Made sure an old washer or oring wasn’t hidden down in the port for the fuel/air screw?
 
ancientdad said:
Then the first step is to thoroughly clean them and re-use them to see how things might change.
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I'm replying now because I realized I didn't before, but somehow when I installed those guys in Houston pilot jet on the right hand side carb, it somehow broke off inside the carb. That's why the bike wasn't behaving or wanting to get better at idling. I ordered some new Amazon carbs, cleaned and refreshed the old OEM hardware, and installed it on the bike. Everything is as it should be now, and the bike rides better than it did before. I'm sufficiently impressed with these Chinese kehin copies!
 
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