Author Topic: I cant figure out what this hose connects to  (Read 1247 times)

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Offline JamesHeller

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I cant figure out what this hose connects to
« on: June 08, 2021, 11:23:35 AM »
And i feel like something dumb is keeping me from being done and riding this bike already :'(
78 Honda Cb750K

Offline goodtryer

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Re: I cant figure out what this hose connects to
« Reply #1 on: June 08, 2021, 11:26:12 AM »
Possibly the overflow drain from the fuel tank.

Or maybe the recycle connection from the valve cover to the airbox.

What bike?
"Tolerance will reach such a level that intelligent people will be banned from thinking so as not to offend the imbeciles."
-Dostoievski

1977 CB550K
1978 CB750K
1973 CB500K

Offline Alan F.

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Re: I cant figure out what this hose connects to
« Reply #2 on: June 08, 2021, 11:34:16 AM »
78 750F was in his intro thread. James if you put which bike you have in your profile signature, it'll be included with every post you make.

Are you sure it's a 750F? I thought those had blacked out engines...

Is there already a hose connected here?


Offline BenelliSEI

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Re: I cant figure out what this hose connects to
« Reply #3 on: June 08, 2021, 12:02:24 PM »
If it’s not long enough to reach the back of the Cam cover, it’s the one to the airbox drain.

Offline bryanj

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Re: I cant figure out what this hose connects to
« Reply #4 on: June 08, 2021, 12:23:53 PM »
Crankcase breather and connects to oil separator i thik
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline madmtnmotors

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Re: I cant figure out what this hose connects to
« Reply #5 on: June 08, 2021, 12:52:57 PM »
It appears to be connected to the vapor/moisture separator under the battery. The other end of this hose would connect to the top of the air cleaner. The vapor/moisture separator should also have a hose connected to the valve cover as well as a drain hose that wraps around the front of the swingarm before routing to the rear.
TAMTF...


Wilbur



Projects:
"Evolution": http://forums.sohc4.net/index.php?topic=100352.0
"P.O. Debacle": http://forums.sohc4.net/index.php/topic,126692.msg1441661.html#msg1441661
F2/F3 O-rings: http://forums.sohc4.net/index.php?topic=113672.msg1300721#msg1300721
Cam Tower Studs: https://www.mcmaster.com/#93210a017/=t19sgp
Clean up that nasty harness: http://forums.sohc4.net/index.php?topic=137351.msg1549191#msg1549191
http://forums.sohc4.net/index.php/topic,148188.msg1688494.html#msg1688494
http://forums.sohc4.net/index.php/topic,139544.msg1579364.html#msg1579364
                                          
Charging system diagnosis: http://forums.sohc4.net/index.php?topic=1012.msg8345#msg8345
Get the manuals: http://manuals.sohc4.net/cb750k/
The Dragon: http://forums.sohc4.net/index.php?topic=45183.msg1571675#msg1571675
Headlight Switch: http://forums.sohc4.net/index.php?topic=113986.msg1283236#msg1283236
Branden's leak free top end thread: http://forums.sohc4.net/index.php?topic=107040.0
Engine Lifting Made Easy: http://forums.sohc4.net/index.php/topic,58210.msg1684742.html#msg1684742
                                      http://forums.sohc4.net/index.php/topic,100352.msg1675840.html#msg1675840
Static and Dynamic Timing: http://www.hondachopper.com/garage/carb_info/timing/timing1.html
Airbox Gasket Replacement: http://forums.sohc4.net/index.php/topic,114485.msg1290000.html#msg1290000
"Café" : http://forums.sohc4.net/index.php/topic,84697.msg953814.html#msg953814
PD Carb Choke Linkage: http://forums.sohc4.net/index.php/topic,100352.msg1669248.html#msg1669248
                                    http://forums.sohc4.net/index.php/topic,110931.msg1248354.html#msg1248354
                                    http://forums.sohc4.net/index.php/topic,48858.msg515204.html#msg515204
Follow up on your damn posts: http://forums.sohc4.net/index.php/topic,144305.msg1791605.html#msg1791605
Taiwanese Cam Chain Tensioners:  http://forums.sohc4.net/index.php/topic,155043.msg1774841.html#msg1774841
Gumtwo Seat Cover: http://forums.sohc4.net/index.php/topic,164440.msg1897366.html#msg1897366
Primary Drive: http://forums.sohc4.net/index.php/topic,166063.msg1919278.html#msg1919278
Tank Latch: http://forums.sohc4.net/index.php/topic,165975.msg1919495.html#msg1919495
Shorten your forks: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-shorten-forks-td4042465.html DO NOT CUT THE SPRINGS!
Clutch How To: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-change-and-adjust-a-clutch-SOHC-td4040391.html
Late model K7/K8/F2/F3 front sprocket cover removal: http://forums.sohc4.net/index.php/topic,178428.msg2072279.html#msg2072279
630 to 530 conversion: http://forums.sohc4.net/index.php/topic,180710.msg2094423.html#msg2094423

Sent from my Tandy TRS-80!

Offline JamesHeller

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Re: I cant figure out what this hose connects to
« Reply #6 on: June 08, 2021, 01:09:50 PM »
78 750F was in his intro thread. James if you put which bike you have in your profile signature, it'll be included with every post you make.

Are you sure it's a 750F? I thought those had blacked out engines...

Is there already a hose connected here?




Yes it is
78 Honda Cb750K

Offline JamesHeller

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Re: I cant figure out what this hose connects to
« Reply #7 on: June 08, 2021, 01:10:52 PM »
If it’s not long enough to reach the back of the Cam cover, it’s the one to the airbox drain.

Thats what i had been thinking but wasn't 100% sure
78 Honda Cb750K

Offline JamesHeller

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Re: I cant figure out what this hose connects to
« Reply #8 on: June 08, 2021, 01:12:35 PM »
It appears to be connected to the vapor/moisture separator under the battery. The other end of this hose would connect to the top of the air cleaner. The vapor/moisture separator should also have a hose connected to the valve cover as well as a drain hose that wraps around the front of the swingarm before routing to the rear.

What is the best thing to do with it now you think cause
78 Honda Cb750K

Offline madmtnmotors

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Re: I cant figure out what this hose connects to
« Reply #9 on: June 08, 2021, 01:20:26 PM »
"cause" what? Because the air cleaner has been jettisoned? If so, then all you can do is stick a filter on the end and vent to atmosphere. DO NOT PLUG THIS BREATHER HOSE. The crankcase pressure must be vented. You could eliminated the breather canister completely and stick the filter on the end of the breather hose from the valve cover would accomplish the same thing.
« Last Edit: June 09, 2021, 04:20:39 AM by madmtnmotors »
TAMTF...


Wilbur



Projects:
"Evolution": http://forums.sohc4.net/index.php?topic=100352.0
"P.O. Debacle": http://forums.sohc4.net/index.php/topic,126692.msg1441661.html#msg1441661
F2/F3 O-rings: http://forums.sohc4.net/index.php?topic=113672.msg1300721#msg1300721
Cam Tower Studs: https://www.mcmaster.com/#93210a017/=t19sgp
Clean up that nasty harness: http://forums.sohc4.net/index.php?topic=137351.msg1549191#msg1549191
http://forums.sohc4.net/index.php/topic,148188.msg1688494.html#msg1688494
http://forums.sohc4.net/index.php/topic,139544.msg1579364.html#msg1579364
                                          
Charging system diagnosis: http://forums.sohc4.net/index.php?topic=1012.msg8345#msg8345
Get the manuals: http://manuals.sohc4.net/cb750k/
The Dragon: http://forums.sohc4.net/index.php?topic=45183.msg1571675#msg1571675
Headlight Switch: http://forums.sohc4.net/index.php?topic=113986.msg1283236#msg1283236
Branden's leak free top end thread: http://forums.sohc4.net/index.php?topic=107040.0
Engine Lifting Made Easy: http://forums.sohc4.net/index.php/topic,58210.msg1684742.html#msg1684742
                                      http://forums.sohc4.net/index.php/topic,100352.msg1675840.html#msg1675840
Static and Dynamic Timing: http://www.hondachopper.com/garage/carb_info/timing/timing1.html
Airbox Gasket Replacement: http://forums.sohc4.net/index.php/topic,114485.msg1290000.html#msg1290000
"Café" : http://forums.sohc4.net/index.php/topic,84697.msg953814.html#msg953814
PD Carb Choke Linkage: http://forums.sohc4.net/index.php/topic,100352.msg1669248.html#msg1669248
                                    http://forums.sohc4.net/index.php/topic,110931.msg1248354.html#msg1248354
                                    http://forums.sohc4.net/index.php/topic,48858.msg515204.html#msg515204
Follow up on your damn posts: http://forums.sohc4.net/index.php/topic,144305.msg1791605.html#msg1791605
Taiwanese Cam Chain Tensioners:  http://forums.sohc4.net/index.php/topic,155043.msg1774841.html#msg1774841
Gumtwo Seat Cover: http://forums.sohc4.net/index.php/topic,164440.msg1897366.html#msg1897366
Primary Drive: http://forums.sohc4.net/index.php/topic,166063.msg1919278.html#msg1919278
Tank Latch: http://forums.sohc4.net/index.php/topic,165975.msg1919495.html#msg1919495
Shorten your forks: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-shorten-forks-td4042465.html DO NOT CUT THE SPRINGS!
Clutch How To: http://vintage-and-classic-honda-s.456789.n3.nabble.com/How-to-change-and-adjust-a-clutch-SOHC-td4040391.html
Late model K7/K8/F2/F3 front sprocket cover removal: http://forums.sohc4.net/index.php/topic,178428.msg2072279.html#msg2072279
630 to 530 conversion: http://forums.sohc4.net/index.php/topic,180710.msg2094423.html#msg2094423

Sent from my Tandy TRS-80!

Offline Alan F.

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Re: I cant figure out what this hose connects to
« Reply #10 on: June 08, 2021, 03:03:08 PM »
Is this your bike?

Why do you think it's a CB750F?

Offline TwoTired

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Re: I cant figure out what this hose connects to
« Reply #11 on: June 08, 2021, 05:40:19 PM »
Should know what bike you have.  F models and K models are both Four cylinder.

Cheers!
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline JamesHeller

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Re: I cant figure out what this hose connects to
« Reply #12 on: June 22, 2021, 11:25:11 AM »
Is this your bike?

Why do you think it's a CB750F?

I has cb750f on it and also Cb750K so i was lost and my grandfather had completey for got which one it was but it is a K model
78 Honda Cb750K

Online newday777

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Re: I cant figure out what this hose connects to
« Reply #13 on: June 23, 2021, 06:56:29 AM »





Is this your bike?

Why do you think it's a CB750F?

I has cb750f on it and also Cb750K so i was lost and my grandfather had completey for got which one it was but it is a K model

78 750 Four is different than the question is it the F model or the K model. F model is the Supersport.
When you ask a question please include the model and year in each new question topic. It avoids confusion.

K model specs and picture


https://www.motorcyclespecs.co.za/model/Honda/honda_cb750k7_77.html

78 F model Supersport in the picture. Notice the differences

Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A