Another Carb Thread - I'm Sorry

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Check slide is fully returning.
Carb bodies are easlily warped, then the slide gets sticky.
Or it can get stuck on the choke or cable.
Check cable routing.
 
A little late but I don't fathom the apology because a bit more knowledge is unearthed each time a subject is broached. I find it interesting following these things to their conclusions for not all are identical...... Most yes, but not all by a long shot. It helps us all out because some of it sticks to the dying brain cells and aides in trouble shooting in the future, so you are far from a boring topic IMO.... Just what one old fart thinks.
 
jbruney said:
A little late but I don't fathom the apology because a bit more knowledge is unearthed each time a subject is broached. I find it interesting following these things to their conclusions for not all are identical...... Most yes, but not all by a long shot. It helps us all out because some of it sticks to the dying brain cells and aides in trouble shooting in the future, so you are far from a boring topic IMO.... Just what one old fart thinks.
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All true ..... but only if the OP follows up and tells us what it was that finally solved his problem. Too often, we are all left hanging when the OP leaves the thread without informing us. Not say'n this OP will do that .....

Slick
 
CanukNortonNut said:
If the slides get worn then so does the needle jet from the needle rubbing against the jet due to the slide rattling back and forth in the carb body.
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The needle rattles around in the needle jet and wears it anyway. Nothing to do with a worn slide.
 
I'm taking the float bowl off today and will clean it, check level, clean carb then retry. Premiers will arrive Saturday so if no dice there I'm going to just bolt those up and see what heppens. Probably find my air leak then :p
 
Eric Bauer said:
I'm taking the float bowl off today and will clean it, check level, clean carb then retry. Premiers will arrive Saturday so if no dice there I'm going to just bolt those up and see what heppens. Probably find my air leak then :p
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You are probably aware that there have been issues with machine swarf in the pilot circuit on new Premiers, so if you have to go that route it pays to dis-assemble and check them thoroughly before fitting.
 
cliffa said:
You are probably aware that there have been issues with machine swarf in the pilot circuit on new Premiers, so if you have to go that route it pays to dis-assemble and check them thoroughly before fitting.
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I have read that - these are actually my first new carbs - always just rebuilt so I plan to take them apart and make sure all is well. Have also heard of wrong jets, etc. The shop I bought them from is changing them at my request, I went with the #19 pilot jet, the 3.5 slide, 260 main, 106 needle. They didn't have the 19 or 3.5 slide as standard, which I think is old news for 850s by my reading,
 
Eric Bauer said:
What is really perplexing to me is why I can set the air screw mixture ok (at least at idle) with the colortune and set the idle properly when hot one day, but then after a ride from cold the next day it runs right back up to 1,500 . That is bizarre to me.
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Sounds like a sinking or sticking float to me. Have you checked that the float needle hasn't got something holding it open on the side that is rich ?
 
Triton Thrasher said:
The needle rattles around in the needle jet and wears it anyway. Nothing to do with a worn slide.
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"The needle rattles around in the needle jet and wears it anyway. Nothing to do with a worn slide. "
Rattling was probably not a good term to use. I should have used the cyclic buzz from the engine in the Isolastic system while running.
1. The needle doesn't rattle as it is held down firm by the return spring over the split clip.
2. The needle is encapsulated by the split clip in the recess pocket in the slide which centers the needle to be guided into the jet from above. As long as the slide/body is within design spec, then all parts have the proper clearances. When the slides and bodies wear the tolerance opens up and ovals the needle jet by the needle now rubbing because needle follows the position of the out of tolerance slide, which creates a 2nd over rich problem by a now oval jet. I have measured the difference with a shadow-graph in a metrology shop. YMMV
Cheers,
Tom
 
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CanukNortonNut said:
"The needle rattles around in the needle jet and wears it anyway. Nothing to do with a worn slide. "
Rattling was probably not a good term to use. I should have used the cyclic buzz from the engine in the Isolastic system while running.
1. The needle doesn't rattle as it is held down firm by the return spring over the split clip.
2. The needle is encapsulated by the split clip in the recess pocket in the slide which centers the needle to be guided into the jet from above. As long as the slide/body is within design spec, then all parts have the proper clearances. When the slides and bodies wear the tolerance opens up and ovals the jet by the needle now rubbing because needle follows the position of the out of tolerance slide, which creates a 2nd over rich problem by a now oval jet. I have measured the difference with a shadow-graph in a metrology shop. YMMV
Cheers,
Tom
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I reckon that’s speculative and dubious.
 
Triton Thrasher said:
I reckon that’s speculative and dubious.
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Triton,
Please explain speculative and dubious? Have you checked out worn needle jet in any way for the forum or are you just being "speculative" or guessing, that your comments are "correct"? I have checked jets, out of spec. with equipment! So are you guessing? Do you have any means of giving the thread your knowledge for input?
 
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I just changed out some rather enlarged .260's, but found the needles in good shape.
 
jbruney said:
I just changed out some rather enlarged .260's, but found the needles in good shape.
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Your main Jets should never get enlarged??? Unless someone opened them up with a drill>>>
They usually get clogged up with crud. Nothing wears the main jet. Only fuel passes through it. Maybe I'm missing something here? The Needle never passes through the Main Jets. Are you talking about your .106 Needle jets?
 
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Replaced .106 & .260.... whole lot, but kept needles. Sorry for being vague. Thoughts were elsewhere.
 
I took the float bowls off and they look about the same - nothing materially incorrect. As you may recall the left side carb runs well so stands to reason that is not the issue. The carbs were taken apart and cleaned around 700 miles ago and it shows. Very clean on the inside. But definitely all original parts (float, etc). Thinking I am probably just going to bolt on the premiers and see how it runs.
 
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