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Discussion Starter #1
So, I decided to replace as many hoses as I can over this winter. I have a few I have taken off the bike, and want to replace and am not sure what is the best way to go about it.

Are factory hoses molded, or have they just been molded due to hot/cold cycles?

Should I order OEM, or just go down to a local parts store and match the size and purpose (vacuum vs fuel)?

Here are the hoses I'm looking to replace right now:







Thanks
 

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I ordered the carb hose in your first pic. Figure a OEM molded version would be best. Could probably do a straight one from auto parts if needed sooner.
Not riding season here lately anyway.
 

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most hoses are molded...
if the room permits , then auto parts store..

a few, there is no choice.
 

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I can speak for the main fuel line. I was also in the midst of changing out a lot of things after a carb rebuild, and like any good gearhead, have lots of different fuel line around. I tried the normal straight stuff - it barely worked (weeped until clamped down way too tight and stressed in places), it became clear the curves at the petcock and carb are there for good reason, so I got the OEM. Much better. Any of the smaller (straighter) stuff would likely be okay to use something else.
 

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Discussion Starter #5
Thanks for the input guys. I ended up doing what I always do... I referenced all the parts, made a spreadsheet with prices and faxed it to my local Honda dealership for them to price match. I decided to stick with OEM. I ordered all the rubber pieces that are fuel/vacuum related. I also ordered an OEM "piston, vacuum" (vacuum diaphragm) to hold onto for when mine tears.

My next stuff will be coolant lines.
 

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Yeah,I went with OEM....made for a more harmonious outcome..... (y)
 

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Honda vacuum hoses uicracked/split on the ID. Replaced early, about as bad as the OEM shock bushings. All my other hoses are original.
 

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Discussion Starter #9
Honda OEM rubber hoses should last the useful life of the bike...
I do not replace hoses unless they are: cracked, hard as a rock, or leaking.
If you zoom in on the end of the vacuum hose that goes to the petcock in my picture you can see cracks. I also don’t like the feel of the fuel line from the petcock to the carb. The vent hose for the gas tank has been ripping each time I remove the tank.

I may not actually install all the new hoses, those that aren’t installed will be boxed and stored for when I need them. I also will keep all removed hoses as backups (since they actually are being preemptively replaced).

For anyone looking, all the vacuum lines, fuel lines, clips for all lines, rubber flange pieces for the manifold, and the carb diaphragm ($70) were $180 with tax.

I didn’t order it yet, but the coolant lines are about $300 for everything.
 

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If you zoom in on the end of the vacuum hose that goes to the petcock in my picture you can see cracks. I also don’t like the feel of the fuel line from the petcock to the carb. The vent hose for the gas tank has been ripping each time I remove the tank.

I may not actually install all the new hoses, those that aren’t installed will be boxed and stored for when I need them. I also will keep all removed hoses as backups (since they actually are being preemptively replaced).

For anyone looking, all the vacuum lines, fuel lines, clips for all lines, rubber flange pieces for the manifold, and the carb diaphragm ($70) were $180 with tax.

I didn’t order it yet, but the coolant lines are about $300 for everything.
If you want, you could replace just the rubber diaphragm only, with this, It says for Harley but will fit your carb;Twin Power Keihin CV Carb Vacuum Piston Diaphram 27690 | eBay
 

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Discussion Starter #11
If you want, you could replace just the rubber diaphragm only, with this, It says for Harley but will fit your carb;Twin Power Keihin CV Carb Vacuum Piston Diaphram 27690 | eBay
Thanks. I already put in the OEM replacement, and kept my original as a spare (no visible cracks). But this is nice to know.

When I had it off I was looking at it to see how people are swapping just the rubber, how do people do it? I couldn’t figure it out. Does it just stretch over the metal cup?
 

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I went with a JBM Industries diaphragm but not exactly the right one.
I cut the red band off to get the tire into the groove. Lefty1998 may not have know about the K72S which fits into the groove. Drill a small hole to help break off the black band. Align and mark with vacuum hole in correct location and the slide with the slide cutout where the throttle butterfly is.
169884
169886
169885
 

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Not a derail... I want to know too. Thanks.
I went to JBM site and found this, Hans says K-72S is correct sized diaphragm, see video associated with the K-72S description

this led me to this:
 

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I updated the carb diaphragm PDF and posted it on the 1300 Step by Step.
One YT video showed someone having trouble with keeping the diaphragm in place. I just pop a 3/4" socket partially in the throttle body to hold the slide in place and never had an issue with the diaphragm coming out of the groove.
 

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Discussion Starter #19
Thanks Hans.

I noticed that when I replaced my diaphragm, that my dyno tuner put some sort of grease around the carb groove. This held the diaphragm lip in place, and actually helped hold the new one in place when I went to install it.

He’s built a ton of bikes (he’s an old school guy) so I’m sure this is a common industry trick. When he’s tuning he would have to have the diaphragm off and on tons of times as he is tweaking the jets/needle.
 
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