Topic: Replacing OEM K1 750 Fuel Lines?

[leovich]

New honda fuel line and carb overflow lines , from what I've seen, do not have red lines on them. The new Honda fuel line is black with silver lettering....the carb overflow line is kinda dark with red lettering....
first pic is current honda  fuel line
the second pic , all carb overflow lines, left to right: J.T. Marks - grey with a red stripe but with lettering "4x8" in between the striping....
            The middle line is vintage 70's honda , ash grey with a continuous solid red stripe, yes, honda bikes in early to possibly later 70's , fuel and overflow lines had continuous red stripes.
             the third line is current honda overflow line , dark with red lettering.

It is same as the center one in your picture, ash gray with continuos red stripe, I also had a ‘73 125 twin with unmolested factory fitted and they’re the same grey with red continuos stripe. I don’t know if in US you have the NC750 x but also on that model the overflow hose from tank is same grey hose with red continuos stripe

[leovich]

This is the hose

[jlh3rd]

This is the hose

hey...do you have the part# handy?....if you do, thanks.

[ZTatZAU]

I really appreciate all the additional information that's been posted here.  There certainly are a number of options.
I've opted for the "Genuine Honda" 5.5mm X 10+mm hose.  And, at this point, my only concern is whether or not the 10+mm OD hose will pass comfortably though the routing holes in the carburetor rack?
ZT

[jlh3rd]

well...Honda has superceded the 5 mm I.D. line with the 5.5. By default, that means it should.

[ZTatZAU]

Likely so, JLH3rd!
I'm knocking on wood.
ZT

[willbird]

I really appreciate all the additional information that's been posted here.  There certainly are a number of options.
I've opted for the "Genuine Honda" 5.5mm X 10+mm hose.  And, at this point, my only concern is whether or not the 10+mm OD hose will pass comfortably though the routing holes in the carburetor rack?
ZT

Worked OK on my K2.

[CycleRanger]

Speaking of Honda hoses. Unfortunately does not show OD.

[bryanj]

From those numbers 95001 means its a hose, the next number starts with the id and the end number is length of roll

[leovich]

This is the hose

hey...do you have the part# handy?....if you do, thanks.

Hi, I haven’t part number right now but if you can find part list for Africa twin 1100 it is the “overflow” hose for carbon canister, going down on the floor near side stand

[HondaMan]

I just got some of the 'new' Honda bulk fuel hose. It doesn't have a red stripe now! Instead, it has printing all over it. I'll see about putting up a picture of it.

[ZTatZAU]

I just received a few feet of the "Genuine Honda" 5.5MM Fuel Hose.  Here's what the hose and markings look like...
https://www.ebay.com/itm/361538699424 ... A bit pricey at $5/foot but wanted to rig up a few feet of the new hose to feed the carbs from the removed elevated gas tank to check float bowl levels and synch the carbs.  Nice and soft, very pliable!  Hope it lasts with ethanol laced fuel.

I also received some 5.5mm muzzleloading flushing nipples with o-rings and clear hose from an outdoors shop in WV to check fuel levels in the bowls. ...  https://www.ebay.com/itm/204117788121?var=504657473007 ... They should work out well.

Also ordered a Morgan Carb Tune Pro 4 after reading several reviews and viewing some YT flicks.  https://www.amazon.com/dp/B018UTHGPE/ref=pe_386300_440135490_TE_simp_item_image

Looking forward to getting everything hooked up and getting my K1 carbs setup properly!

[Don R]

 Start with the morgan carbtune by reading the carb balancing section of the Honda service manual for your bike. It will save a lot of questions.

[willbird]

Start with the morgan carbtune by reading the carb balancing section of the Honda service manual for your bike. It will save a lot of questions.

It seemed from reading the instructions that one should avoid snapping the throttles closed and sucking all of the fluid out of it ?? I read the destructions when pondering about buying one. I’m just using some gauges for the time being myself.

[ZTatZAU]

Start with the morgan carbtune by reading the carb balancing section of the Honda service manual for your bike. It will save a lot of questions.

It seemed from reading the instructions that one should avoid snapping the throttles closed and sucking all of the fluid out of it ?? I read the destructions when pondering about buying one. I’m just using some gauges for the time being myself.

You may be confusing the MOTION PRO SYNC PRO CARB TUNER and the Morgan Carb Tune Pro 4 Synchronizer.  I remember reading the comments and warning about snapping the throttles sucking the fluid out of the Motion Pro unit but the Morgan unit uses steel rods in glass tubes, so there's no fluid to suck.

At least that's how I understand it!  I ordered the Morgan Carb Tune Pro 4.
ZT

[newday777]

Start with the morgan carbtune by reading the carb balancing section of the Honda service manual for your bike. It will save a lot of questions.

It seemed from reading the instructions that one should avoid snapping the throttles closed and sucking all of the fluid out of it ?? I read the destructions when pondering about buying one. I’m just using some gauges for the time being myself.

My Morgan Carbtune Pro4 doesn't have liquid in it

[newday777]

Morgan Carbtune has steel rods

[willbird]

Start with the morgan carbtune by reading the carb balancing section of the Honda service manual for your bike. It will save a lot of questions.

It seemed from reading the instructions that one should avoid snapping the throttles closed and sucking all of the fluid out of it ?? I read the destructions when pondering about buying one. I’m just using some gauges for the time being myself.

My Morgan Carbtune Pro4 doesn't have liquid in it

Must have been the Motion pro synchpro, sorry for my confusion :-).

[ZTatZAU]

Start with the morgan carbtune by reading the carb balancing section of the Honda service manual for your bike. It will save a lot of questions.

I've set my valve tappet clearances and ignition timing, verified the fuel levels in my carb bowls via the clear tube method, and believe I'm ready to synch my carbs with my new Morgan CarbTune Pro...



As per Don R's advice, I looked over the carb synch procedure contained in the CB750 SM, K1-K4 Supplement again.  It all seemed pretty straight forward if not a bit out of sequence (i.e. Before synchronizing Note; coming between step 4 and step 5 of the procedure).

After cleaning and reassembling the carbs, I didn't do much of anything to "Bench Synch" the carbs other than reinstalling the 4 carbs, as they were before, on the linkage rack.  The carb slides, needles, top caps, and adjusters were not disturbed during the Ultrasonic cleaning, and all the components went back where they came from, so I didn't think there was much if anything to setup on the bench before installing the 4 carb assembly.  Please correct and educate me if this was an incorrect assumption.

After a bit of warm up, at  about 1100 rpms, the carbtune pro showed all four carbs within a couple of cmHg down low on the scale.  Without adjusting anything but opening the throttle, to get the vacuum up into the 20 cmHg range, I saw 18, 20, 22, & 20 cmHG on carbs 1 through 4 respectfully.  I.E.  All within the specified 16-24 range and pretty close to the specified 3 cmHg difference.

I do not feel like I'm finished and would like to do some adjusting to get the four carbs a little closer together.  My questions are...

I've seen a number of references here on SOHC4, to the "1/8" drill bit trick" but never found any info on the trick itself.  Is the "drill bit trick" intended to closely approximate the specified 0.070-0.189" distance between the top of the carb and the bottom of the adjuster screw/nut?

And is setting this 1/8" space with the adjusters first, where I should be starting at this point, or should I just start adjusting to achieve 20 cmHg on each carb... and whatever rpms result... and then readjusting the idle stop screw for the correct idle speed?

Thanks for any advice/suggestions on this  ZT

[bryanj]

1/8 is too big you need a new 1/16 with unscarred shank.
With carbs off look into the holes on engine side and unscrew the big tickover screw till all the slides hit the bottom then screw the big screw in until the drill shank just slides under the first one to open like usining a feeler gauge after this you use the top adjuster screws on the other 3 to get the slides equally open

[ZTatZAU]

1/8 is too big you need a new 1/16 with unscarred shank.
With carbs off look into the holes on engine side and unscrew the big tickover screw till all the slides hit the bottom then screw the big screw in until the drill shank just slides under the first one to open like usining a feeler gauge after this you use the top adjuster screws on the other 3 to get the slides equally open

I appreciate the info Bryan and It would take me a while to figure out exactly what you're describing (tickover screw?)... but at this point I'm a bit hesitant to remove the carbs again.  Any suggestions on how best to proceed from where I'm at now would be appreciated?
ZT

[bryanj]

There is big screw that adjusts the rack bar that lifts the slides and adjusts the tickover--------tickover screw

[newday777]

1/8 is too big you need a new 1/16 with unscarred shank.
With carbs off look into the holes on engine side and unscrew the big tickover screw till all the slides hit the bottom then screw the big screw in until the drill shank just slides under the first one to open like usining a feeler gauge after this you use the top adjuster screws on the other 3 to get the slides equally open

I appreciate the info Bryan and It would take me a while to figure out exactly what you're describing (tickover screw?)... but at this point I'm a bit hesitant to remove the carbs again.  Any suggestions on how best to proceed from where I'm at now would be appreciated?
ZT

Use Google search.... what is British tickover

[RAFster122s]

Search on Google with this string added to give you results from SOHC4 forum

"site=https://forums.sohc4.net"

[newday777]

Search on Google with this string added to give you results from SOHC4 forum

"site=https://forums.sohc4.net"

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