CL160 carb needle query

[SuperSquirrel]

Hi, I am thinking of replacing the needles - are the Dellorto ones ok? Or what to look for? My bike is mostly fine but after a few miles at 50mph or so and then slowing down it feels unhappy and doesn't pick up smoothly on acceleration. Doesn't feel like ignition and the valve clearances are ok. Feels like fuel starvation. I'm in the middle of checking the carbs off the bike and wonder whether I've got Keyster needles. I'll be checking float height and fuel flow anyway. Just wondered whether this is known problem,

Cheers everyone

 

[ancientdad]

Moved to Smaller Twins Carburetion section.

Did you check JetsRUs to see if they have original Keihin needles?

 

[deckeda]

... My bike is mostly fine but after a few miles at 50mph or so and then slowing down it feels unhappy and doesn't pick up smoothly on acceleration ...

Does the service manual for this model list a different spark plug for "extended highway riding" or similar verbiage? Mine is much newer than yours but they still list 3 potential spark plug heat ranges depending on ambient temps/extended rpm usage and so on.

 

[SuperSquirrel]

Hi deckeda, thanks, I didn’t know that, I’ll take a look.

As it happens, on stripping the suspect carb I found the float height wrong, was giving a lean mixture. I had a good read on the relevant thread and adjusted it as best I could, compromising on the reference level on the carb body - opinion seems to be divided on exactly where it is.

A quick blast seems to show a marked improvement, longer ride to follow.

 

[SuperSquirrel]

JetsRUs didn’t have any but I found some (allegedly) genuine ones in the UK, haven’t fitted them yet though

 

[SuperSquirrel]

Hi again everyone.
I have been right round the track with my keihin carbs and think I must admit defeat. The bike is fine to ride but the LH carb wont adjust for tickover. Float height correct, carb ultrasonically cleaned, all jets clean. But the aftermarket float needles are suspect and so in my opinion are the jets.

So, can anyone advise whether a new high quaiity pair of Mikunis would fit atraight on? The rest of
the bike is excellent, it would be a pity to give up,

Cheers all and thanks

 

[ballbearian]

Hi again everyone.
I have been right round the track with my keihin carbs and think I must admit defeat. The bike is fine to ride but the LH carb wont adjust for tickover. Float height correct, carb ultrasonically cleaned, all jets clean. But the aftermarket float needles are suspect and so in my opinion are the jets.

So, can anyone advise whether a new high quaiity pair of Mikunis would fit atraight on? The rest of
the bike is excellent, it would be a pity to give up,

Cheers all and thanks

Don't give up. I've had to ultrasonic them more than once and there are many times that didn't do the trick but had to spray carb cleaner in every single port and passage and then use high pressure air as well, then back into the ultrasonic. It really sounds like there is still a plugged or partial blockage. Put on eye protection and find a compressor. Check your slide bores and slides for stickage as well.

 

[Flyin900]

Hi again everyone.
I have been right round the track with my keihin carbs and think I must admit defeat. The bike is fine to ride but the LH carb wont adjust for tickover. Float height correct, carb ultrasonically cleaned, all jets clean. But the aftermarket float needles are suspect and so in my opinion are the jets.

So, can anyone advise whether a new high quaiity pair of Mikunis would fit atraight on? The rest of
the bike is excellent, it would be a pity to give up,

Cheers all and thanks

The jetting should be the correct original Keihin parts with the stylized K on them with the correct jet size per the Honda manual. The float needle brand makes no difference, as long as the setting is correct at whatever the Honda manual specifies as the correct height. It’s only purpose is to open and close the fuel into the carb. Now if you have an incorrect size number on that fuel valve that could pose a problem. They normally have a number stamped on the top of the brass such as 2.0 as a size.

Smooth opening and closing of both the carb slides in the bodies and the fuel needles are two important aspects of operation. If the fuel valve was hanging up, or the float on the float pin sticking you would likely have fuel overflow issues from the brass tube on the float bowl.

If your issue is an idle only one now and it runs and pulls well, the idle circuit is still possibly dirty. This is the slow speed jet and the air screw or fuel screw mixture passage and adjustment for correct operation.

 

[SuperSquirrel]

Thanks guys for your encourgement and reassurance, I'll check the jets, make sure the float is working properly, check the action of the slide and needle and persevere with cleaning up the drillings. Further report in due course,

Cheers, Rchard

 

[SuperSquirrel]

It's been a while I know but it's now sorted. A friend (an Enfield man) took the carbs and put them through his U/S cleaner and high pressure hose several times, also adjusted my rubbish float height setting and after spending a while synchronising them and getting the mixture right the bike is now running nicely, so thank you all for your advice and encouragement. A good welcoming helpful group you are too,

Cheers, Richard

 

[ancientdad]

It's been a while I know but it's now sorted. A friend (an Enfield man) took the carbs and put them through his U/S cleaner and high pressure hose several times, also adjusted my rubbish float height setting and after spending a while synchronising them and getting the mixture right the bike is now running nicely, so thank you all for your advice and encouragement. A good welcoming helpful group you are too,

Cheers, Richard

Glad you got it sorted Richard, and thanks for the kind words. You don't have to come around only when you need help, we're here to have fun too so don't be a stranger.

 

[ballbearian]

It's been a while I know but it's now sorted. A friend (an Enfield man) took the carbs and put them through his U/S cleaner and high pressure hose several times, also adjusted my rubbish float height setting and after spending a while synchronising them and getting the mixture right the bike is now running nicely, so thank you all for your advice and encouragement. A good welcoming helpful group you are too,

Cheers, Richard

Great. If you don't give up, you can't be beat.