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Author Topic: 1977 Honda 750 Supersport  (Read 6228 times)

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Offline bjbuchanan

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Re: 1977 Honda 750 Supersport
« Reply #25 on: October 15, 2012, 08:57:03 AM »
The seafoam loosened up all the crud
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Offline Don R

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Re: 1977 Honda 750 Supersport
« Reply #26 on: October 15, 2012, 10:06:11 AM »
You don't cut the gasket, you put one end over the rocker/cam  cover and slip it under the cover then do the other end. Then carefully align it with the shape of the cover and slip it over the dowel posts. The hard part might be cleaning off the old one.
 The seafoam might have loosened goo and/or rust in the tank. There was originally a screen inside the tank over the fuel petcock. It may or may not still be in there, if it is it might be covered with gunk of it it's gone the gunk may have made it into your carbs. It was inevitable if it is that problem.
The seafoam might have hurried the process.
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Offline Jiminy Indy

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Re: 1977 Honda 750 Supersport
« Reply #27 on: October 15, 2012, 10:59:52 AM »
Prolly a good idea to take off your petcock and clean it out anyway. Plus fuel line filters are a cheap and easy way from any gunk getting to your carbs. I like the cleat glass ones at JP Cycles since you can see when they start to gunk up and the filters are replaceable.
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Offline reliv77

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Re: 1977 Honda 750 Supersport
« Reply #28 on: October 15, 2012, 11:55:22 AM »
I took the Fuel Tank off and the Petcock. Drained all the Fuel into a Glass Jar. The Fuel looks Super Clean. Wondering if I should still add the Seafoam to a new tank of Fuel???
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Offline TwoTired

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Re: 1977 Honda 750 Supersport
« Reply #29 on: October 15, 2012, 02:24:43 PM »
I've tried seafoam several times and have seen no measurable effect other than the engine being down on power due to reduction in energy content of the diluted fuel.
If it's clean, seafoam won't make it any cleaner, anyway.

I know many people swear by seafoam.  It's never done anything for me or my bikes except make my wallet thinner.  A miracle potion it is not, imo.

If you still have the in tank fuel filter in good shape, that's all you need.  Filtering it twice or 3-10 times won't make the fuel any cleaner.  Further, inline filters can get restrictive as they accumulate particles leading to another set of issues.   And, if you don't route the lines correctly, the gravity feed fuel system can't work correctly.
In line fuel filters are cheap for a reason.  They cost even less to make than to buy.

Have you yet completed the 3K tune up schedule and vacuum balanced the carbs?

If you had a problem mid-ride, then take a look at the spark plug tips and check the exhaust head pipes for even heat.

Improper adjustment of points can certainly make the bike "limp".
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Lloyd... (SOHC4 #11 Original Mail List)
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Offline reliv77

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Re: 1977 Honda 750 Supersport
« Reply #30 on: October 15, 2012, 02:42:30 PM »
That is what the Bike seemed to do with the Seafoam, loss of power. When I pulled the Petcock out of the Fuel Tank, the only thing I saw was a short Plastic Pipe connected to the Petcock. Would the Original Fuel Filter be there? I do have an external Fuel Filter (clear plastic) and it looks really clean.
Still have not done a 3K tune up or Vacuum Balance.
What is all involved in a 3K Tune Up?
No idea how to do a Vacuum Balance.
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Offline TwoTired

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Re: 1977 Honda 750 Supersport
« Reply #31 on: October 15, 2012, 06:37:44 PM »
Quote from: reliv77 on October 15, 2012, 02:42:30 PM
That is what the Bike seemed to do with the Seafoam, loss of power. When I pulled the Petcock out of the Fuel Tank, the only thing I saw was a short Plastic Pipe connected to the Petcock. Would the Original Fuel Filter be there?
Should be. Could be.  It also could have been destroyed by Mr. ham hands during it's life when trying to remove it, and a cheap filter then put in to recover from their flub.  The original filter fits pretty tightly in the tank bung (look very closely, shine a light in the hole) and doesn't usually come out with the fuel valve on your model bike.

Quote from: reliv77 on October 15, 2012, 02:42:30 PM
Still have not done a 3K tune up or Vacuum Balance.
What is all involved in a 3K Tune Up?
No idea how to do a Vacuum Balance.

Well then, stop complaining about poor performance or run issues until you do the basic maintenance.  ;D
 You got some learning to do and shop manuals to read!!  ;)

Cheers,
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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

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Offline 736cc

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Re: 1977 Honda 750 Supersport
« Reply #32 on: October 15, 2012, 07:42:50 PM »
Quote
That is what the Bike seemed to do with the Seafoam, loss of power. When I pulled the Petcock out of the Fuel Tank, the only thing I saw was a short Plastic Pipe connected to the Petcock. Would the Original Fuel Filter be there? I do have an external Fuel Filter (clear plastic) and it looks really clean.
The Supersport fuel strainer/filter is inside the tank; its in the threaded petcock mount and difficult to remove without mangling it. New from Honda it comes w/ a new o-ring.
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Offline reliv77

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Re: 1977 Honda 750 Supersport
« Reply #33 on: October 16, 2012, 04:58:36 AM »
I am not complaining about poor performance. I am here posting to learn from you guys ( the best source I have come across). I tried to download the PDF Shop Manual from this sight, but it will not download for me.  Where can I find a Shop Manual for a 1977 Honda 750F Supersport? Are the Tune Up Parts available through Honda Dealers or are there better sources?
 Thanks for all the help so far.
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Offline TwoTired

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Re: 1977 Honda 750 Supersport
« Reply #34 on: October 16, 2012, 08:54:33 AM »
Quote from: reliv77 on October 16, 2012, 04:58:36 AM
I am not complaining about poor performance. I am here posting to learn from you guys ( the best source I have come across). I tried to download the PDF Shop Manual from this sight, but it will not download for me.  Where can I find a Shop Manual for a 1977 Honda 750F Supersport? Are the Tune Up Parts available through Honda Dealers or are there better sources?
 Thanks for all the help so far.
You can buy a paper copy of the CB750 Shop manual from helminc.com
I don't think there is a "better" source for Honda components than from Honda... that is, when they still have the item in stock.  Some of the parts on 30-40 year old models are discontinued.  It doesn't hurt to ask them.
However, if there is enough demand, they will make more parts.  They are businessmen.
Lots of parts are only profitable to make when there are high quantities.  If it costs $5000 to set up a production run of parts, they aren't going to set up to make 10 parts @ $50 each.  There are also costs for storing unsold parts, which eat into the profit line.  So, making a bunch just to sit in warehouses doesn't make sense, either.  However, if there are 100,000 requests for a certain part.  They will make more parts.

So, you cheap bastards (you know who you are) that are trying to save a buck on substandard aftermarket parts are contributing to the number of "discontinued" items from Honda!   ;D

Cheers,
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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 reliv77

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Re: 1977 Honda 750 Supersport
« Reply #35 on: October 17, 2012, 05:58:51 AM »
On ebay there is a:
"Clymer Honda In-Line Fours CB750 SOHC Manual M341 Honda CB750F Super Sport 75-78 Service / Repair Manual" for sale. Seems to be more related to the Honda 750's for $33.26. Looks what I need?
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Offline Jiminy Indy

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Re: 1977 Honda 750 Supersport
« Reply #36 on: October 17, 2012, 06:30:33 AM »
The Clymer & Haynes versions are both good. I have both plus the Honda Shop Manual & the HondaMan book. In my opinion the Clymer & Haynes are more directed toward us rookie-tpes and the Shop Manual toward the Honda mechanic. Just a little different perspective is all. They are all good and all have the right information. Just my 2-cents worth.
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Offline TwoTired

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Re: 1977 Honda 750 Supersport
« Reply #37 on: October 17, 2012, 09:28:12 AM »
Quote from: reliv77 on October 17, 2012, 05:58:51 AM
On ebay there is a:
"Clymer Honda In-Line Fours CB750 SOHC Manual M341 Honda CB750F Super Sport 75-78 Service / Repair Manual" for sale. Seems to be more related to the Honda 750's for $33.26. Looks what I need?
It's better than nothing, but not nearly as good or as accurate as the Honda shop manual.  I have both the Honda and Clymer manuals and I seldom use the Clymer, it has mislead me far too often to trust.

I would agree that the Clymer is more directed at the newbie.  But, there is just plain wrong stuff in there which, imo, is hardly beneficial to the newbie.

Cheers,
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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 CafeDawg

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Re: 1977 Honda 750 Supersport
« Reply #38 on: October 17, 2012, 09:55:41 AM »
reliv77  I would try to download again if not here then their are other sites with them as well, for free.  Remember Google is your friend.  This site has a lot of info and can be overwhelming, I know it's taken me three years just to start understanding terminology and some of the specific design of these bikes.  You need to do a lot of reading and searching if you are going to get involved in fixing your own bike.  That being said the info and help is here but you need to look at FAQ area and the sellers area to start getting an idea of what can be done and where parts can be sourced from;  ebay is one option, dealership is another, Partsnmore, bilebandit, oldbikebarn, 750supply, CSML, are others.

A couple answers to your question....The cap that is leaking is the Tappet cover I think and new gaskets are available at a number of places.  To Vacuum Synch your carbs you need a specific tool with four gauges, one for each carb, about a $70 piece and their are links here and Youtube showing how to use it.  Their is a member here who puts together allen kits specific for their model.   The manual has torque specs for almost all the nuts and bolts on the bike so you won't over tighten anything.

To get it running right is a process, just like the Tbird...oil,fuel, plugs. airfilter good places to start.  I'm sure Cleveland has someone who can synch the carbs for ya.  Also the is a mix screw with a knurled end up by the carbs which might be misajusted which can affect idle. 

Just take your time and try and sift through all the info here and the suggestions people throw at you.  In the end I find it's worth all the effort!

Respect
CD
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