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Discussion Starter · #1 ·
What is the Honda way to tighten the carbs on my CL175? the O ring causes carb & manifold to sit apart when bolt finger tightened, do I tighten fully so the ring is compressed or would this distort the flanges, there is a spring washer on the bolts so I assume they must be fully tightened.
 

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You need to tighten them as you would any other bolt - only you have to do it evenly on each side of the carb.
Meaning a little bit on one side, then a little bit on the other, repeat until both are tight - otherwise the the o-ring will distort and leave you with a monstorus air leak, which will cause instant redline when you start it up.

Don't ask how I know this...........
 

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Sensei
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I generally cut a full gasket that fits just outside of, and use the o-ring... This also further helps reduce heat transfer to the carb body.... Not sure it is worth the time/effort, but it works for me..... You still have to gradually tighten the bolts down to avoid leaks, but they are less likely and the o-ring doesn't get completely crushed flat........ :D Steve
 

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Discussion Starter · #4 ·
OK thanks both, it was as I thought then metal face to face. I had used a smear of vaseline on the 'O' ring to try to stop the ring from binding on the metal face. I like the gasket idea Steve, maybe next time if I can get it back to the UK.
 

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Discussion Starter · #5 ·
Steve can you tell me what thickness of gasket paper you use please.

tbpmusic said:
You need to tighten them as you would any other bolt - only you have to do it evenly on each side of the carb.
Meaning a little bit on one side, then a little bit on the other, repeat until both are tight - otherwise the the o-ring will distort and leave you with a monstorus air leak, which will cause instant redline when you start it up.
I had a similar problem to this but found when I tightened the carbs fully the carb body distorted enough to cause the the slide to stick, the only cure was to slacken the bolts slightly to give a few thou gap and the o-ring creating a flexible seal. I am hoping a gasket would allow me to tighten the bolt more.
 

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I do like Steve's idea of a full gasket to distribute the pressure across the entire matching faces. ya'll might remember the tightening issue I have on my cb125s.... I'm experimenting with copper gasket material to add a "crush effect" that will hopefully be enuff seal to prevent body distortion. Don't make my mistake and over tighten those nuts! danWI
 

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Discussion Starter · #7 ·
danWI you had this body distortion problem too? I had not seen any mention of it anywhere before, could the o-ring have been replaced and be too large diameter or too hard perhaps.
 

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Sensei
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I should think either condition would cause a problem.... My parts fiche lists them at 27 x 2.4mm which is an unusual sizing.... Most of the replacements I've found are even 1/2 mm sizes (27 x 2.50) ...Perhaps that is a critical measurement, and my gaskets allow for it...
 

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Discussion Starter · #9 ·
Thanks for that information Steve, so do you know the thickness of gasket material you use. My carbs are held on with hex socket head screws too which doesn't seem original.
 

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Discussion Starter · #11 ·
OK an update on this now I have the bike here.

The grooves on my carbs measure 24mm inner dia x 3mm wide x 2mm deep, so I think O rings need to be 24mm ID - 2.5mm dia, the ones removed were about 25/26 mm ID x 3mm dia that was enough to 'bow' the flanges when trying to tightened fully. Has anyone had any luck trying to straighten 'bowed' flanges? or do I go straight to the gasket mod.
Steve do you happen to have a template or do you just cut a gasket from scratch each time.
 

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Sensei
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I just trace and cut....I also recommend a thin film of Hondabond......You can file the flange flat and forget the o-ring.....
 

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Discussion Starter · #13 ·
Just noticed I hadn't updated this thread, it may be of help to someone in the future.

I got hold of O rings ID - 24mm Dia - 2.5mm and they were perfect without a gasket just a smear of Hylomar, as I said earlier the carbs are held with socket head screws which allowed a little more leverage than a philips head would, so I tightened fully, it no longer distorted the carb body the slides are very smooth and close fully, in fact the tightening seemed to flatten out the bowing of the flange.
 

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Just noticed I hadn't updated this thread, it may be of help to someone in the future.

I got hold of O rings ID - 24mm Dia - 2.5mm and they were perfect without a gasket just a smear of Hylomar, as I said earlier the carbs are held with socket head screws which allowed a little more leverage than a philips head would, so I tightened fully, it no longer distorted the carb body the slides are very smooth and close fully, in fact the tightening seemed to flatten out the bowing of the flange.
Im hoping that this will solve my problems. I have been chasing my tail on my cl175. I cannot for the life of me get it to idle. It revs up like crazy then dies. With my 350 I was able to solve this problem with the wd40 method, track down the leak and fix it. however on this bike I don't seem to get and result from spraying. It still seems like vacuum leak symptoms though. I've checked the carb slides and float height, timing, petcock, fuel lines, cleaned carbs multiple times. I have even smeared liquid gasket over all the sealing surfaces with no luck. I'm gonna try cutting a gasket now to fit around the O-ring.
 

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As stated above, you can just cut 6 gaskets and forget the o-rings. I do this, and it works great. Also as stated above, lap the aluminum flanges and spacers flat on both sides.
 
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