Author Topic: 77' 750F exhaust system  (Read 1405 times)

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Beakin

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77' 750F exhaust system
« on: May 07, 2009, 02:18:21 PM »
So i just picked up a 750 super sport last week and have started its restoration/cafe transformation..

This is my first motorcycle, so im a newbie, bare with me

figured id start with the exhaust because there are a few leaks in the muffler

Heres a picture of part of the header






there is quite a dent in it, im not sure if a over night soak in vinegar will do the trick for that rust

It looks like this bike has been down a couple of times there are tons of road scars




I have a chance to pick up some used headers for 50 bucks i dont know how much better condition they are in..I Should probably go for them right??

Ive been looking for a muffler online and haven't found much..
heres one i found at the oldbikebarn


http://www.oldbikebarn.com/Chrome-Megaphone-Muffler-CB-750-F2?sc=12&category=52291

does anyone have any experience with this one, does its finish last? how does it sound? it fits alright?

any other recommendations on a muffler? Ive been told to stay away from the MAC systems..

thanks!




fuzzybutt

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Re: 77' 750F exhaust system
« Reply #1 on: May 07, 2009, 02:38:10 PM »
you might want to read through this thread before you give the old bike barn any of your hard earned money  http://forums.sohc4.net/index.php?topic=7235.0

Offline Geeto67

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Re: 77' 750F exhaust system
« Reply #2 on: May 07, 2009, 02:52:27 PM »
I would be interested in buying the stock muffler off of you if there are no holes in it and it is not dinged to #$%*. I don't need the head pipe, just the can from the collector back.

Honestly, a Mac pipe is pretty cheap and easy to obtain pretty much anywhere. it wil be brand new and a full system for around $200. I would buy from z1enterprises before oldbike barn, espically since z1enterprises is a member here and highly recommended.

Dynoman.net sells Kerkers but at $700+ they can be pricey. Worth it though.

don't just buy any old crap lying around - there are model differences you need t be aware of (for instance, if you buy a $50 header for a 69-76K bike you need to convert to the K head mounts). Collect more info about the parts you want to buy before you go shelling out nickels and dimes here and there unless you want this bike to nickel and dime you to death.

I hate to say it but you picked a lousy first motorcycle since the thing is such a project. you are going to spend more fixing that wreck than you would if you bought a decent runner. I hope you at least got a title. From what I can see you are looking at probably about $1000 in service parts before you even get to the cosmetics of it.

Bike most likely needs:
Tires
brake rebuild of all the calipers and master cylinders
brake lines
brake pads
carb rebuilds
cables
tank flush
oil and filters
battery
air filter
chain
sprockets
(maybe) gaskets

your first step should be to clean and de-rust the bike. Spend a good long time just getting her tidy so you know what you are looking at. Then start by evaluating what works and what doesn't. Put a battery and check for spark. Put a compression tester on it and check the compression. Don;t worry about buying pipes until you know the mill is sound. If it isn't might as well break her down and rebuild the engine or part her out.

and don't put dime one into it unless you have a title.

 
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Offline Geeto67

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Re: 77' 750F exhaust system
« Reply #3 on: May 07, 2009, 03:00:09 PM »
and another thing - forget cafe-ing that bike for at least a year. If this truly is your first bike get her running and road worthy and learn to ride. It will probably take you a year to sort out that wreck anyway before it would even be a good canidate to start chopping up considering your lack of expirence. It is always easier to modify a running rideable bike than it is to start from a complete wreck when you don't know what you are doing.

if you start out by throwing a lot of big ticket parts on a junk bike all you will have is a very expensive junk bike. You need a solid foundation.

this applies to your riding as well, cafe bikes are not easy to ride. They are cantankerous, twitchy, and generally uncomfortable. Plus they promote bad riding habits (hard to look over your shoulder when you are in a racer's crouch). Get her sorted, devlop good riding habits, then move to the next level. right now it looks like you want to run a marathon without learning how to walk first.

 

Maintenance Matters Most

Beakin

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Re: 77' 750F exhaust system
« Reply #4 on: May 07, 2009, 03:07:35 PM »
I'm fine throwing 1000$ into it i got it for 500, the bike runs, not bad actually, its a little rough at idle but will idle with the choke all the way down.. I was looking for one for over a month and was having no luck.. So i jumped on this one

right now i think it has a 73 engine in it.. made from 2 basket cases.. It came with 5 large Tupperware boxes of parts.. i went through everything, i defiantly have a lot of work ahead of me..

some future plans are to get some new valvues and guides for the original engine from the dynoman dude.. ( the owner said he found the exhaust valve guides were the only thing wrong with the original engine)..

blast the frame down and probably paint it myself.. How much is it generally to powder coat a frame?




Beakin

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Re: 77' 750F exhaust system
« Reply #5 on: May 07, 2009, 03:13:05 PM »
you dont want the stock muffler.. there a at least 2 major holes and some serious road rash

Its not like the clubmans are going on tomorrow or at least for a month or two.. Im doing a course this month, I drove a scooter 5 days a week last year, so im not completely new, i also understand its not the same..

I find I learn the most going into things head first.. I take my time though and im gonna make sure everything right..

But you gotta start somewhere, im pretty determined to make this work

Beakin

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Re: 77' 750F exhaust system
« Reply #6 on: May 07, 2009, 03:15:48 PM »
and yes i have the title

Beakin

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Re: 77' 750F exhaust system
« Reply #7 on: May 07, 2009, 03:21:08 PM »
you might want to read through this thread before you give the old bike barn any of your hard earned money  http://forums.sohc4.net/index.php?topic=7235.0

thanks for this..

and ill look into z1enterprises, and take the advise i was given and stay away from MAC aswell..

I have to sets of the headmounts.. im guessing one for the 73 K model and one for the supersport

Offline Geeto67

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Re: 77' 750F exhaust system
« Reply #8 on: May 07, 2009, 03:36:11 PM »
if the rings, the pistons, the bearings or the head is screwed, you ain't going to make that work without serious monetary investment.

Step one: Clean
Step two: Evaulate

- Put a compression tester on it and make sure all the holes are within 10% of each other and 90 psi or over.
- Change oil and sift through old oil for any large pieces of metal
- put it on the main stand and with the motor running check the tranny to make sure it shifts through all the gears (be very careful about this one - if the bike rocks back it could go shooting off the stand - best to do it with the front tire against a solid wall - not drywall)

If any of the above three things don't check out let us know and we will tell you where to go from there.

Exhaust is like step 15 or so. No point in buying a pipe if you don't even know if the engine is any good.

I admire your enthuasim but really you are not the first newbie to spout pigheaded statements like "i rode a scooter for 5 days so I know what I am doing" and "I am determined to make this work".

Habits are devloped over time. You need a rideable bike to devlop good riding habits and instincts. you need to get there first. You may find that once the bike is in use you don't want a cafe anymore, or you may strengthen your resolve. Lots change when you actually get to evaulate the bike in action.

The success of any project depends on how well it is planned out. blindly spending money is not a plan. You need to evaluate what it is you have. Do you even know the common problems to look for on this bike yet? you need to know where you stand in order to make real measured progress, otherwise - you are just pissing money away.

you are probably going to be more than a little disappointed when you get up to the step that involves clubmans.

valve guides on a 78F engine are a common problem. not a super big deal but you may be a little surprised at the cost.

post the engine number and we can tell you what the engine actually is from. 73 and 78 have different chain sizes and lines so hopefully the P/o knew what he was doing and got the right parts setup, otherwise you are in for a nasty surprise when you go to ride it.

« Last Edit: May 07, 2009, 03:39:24 PM by Geeto67 »
Maintenance Matters Most

Beakin

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Re: 77' 750F exhaust system
« Reply #9 on: May 07, 2009, 03:48:54 PM »
Geez, i appreciate the help but i don't understand why you have to insult me and twist my words(I said 5 times a week for a year, 40 kilometers a day in the city.. and i never said i know what im doing)

I was just pointing out that i have riden on the road with two wheels and know more then someone that hasn't, but obviously i don't know everything, probably not even 1/4 of what i need to know to be a safe motorcycle rider, but leave that to me. I here to get opinions and advise on my bike, not on me.

the P/O says hes put over 30,000 miles on the engine thats in there now, I got my friend to ride it home, hes still alive..
checking the cranking pressure was on my list of things to do, and ill for sure change the oil.

as for the gears, they seem to work fine except when my friend was riding it at maybe 90km/h it dropped into neutral when he was shifting.. but didn't happen again (obviously there is a problem that needs to be looked at there)

where can i find the engine number?

thanks
« Last Edit: May 07, 2009, 03:54:39 PM by Beakin »

Offline Geeto67

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Re: 77' 750F exhaust system
« Reply #10 on: May 07, 2009, 04:28:18 PM »
just trying to help you get on track and focus for the task at hand. Ebay is littered with project bikes where people bought them and just threw a bunch of parts at them and either got no where or built a bike that turned them off to vintage bikes or riding all together.

Who you are as a rider is part of the expirence of being a motorcyclist. The point of this board is useful advice on all those subject. Maybe you don't see it now but you will in time.

cafe bikes are the new it fashon so your first post here aligning yourself with the horde of people drawn to motorcycling by the same motivation opens you up to the same assumptions drawn from the multitude of people who came before. Some moved on to other fashions, others stayed. In the end this expirence is up to you, and we are here to help.

Information is your friend. The more you give us about your bike and project the more you will get back. It is usually a good idea for your first post to be an introductory one so people get to know just how they can help you given your paticular situation. The less you tell us the more assumptions we are forced to make in order to answer your questions.

Looking at that wreck I would not have guessed it runs and was even marginally rideable. Most that look like that are not. Good to know that it is, since it saves you some time.

You are more than likely going to need a carb rebuild if the bike does not run without choke.

Engine number should be on the left side on a pad underneath the carbs.
Maintenance Matters Most

Beakin

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Re: 77' 750F exhaust system
« Reply #11 on: May 07, 2009, 04:34:18 PM »
The bike does run with no choke.. This thread was originally to get some feedback on exhaust headers and mufflers.. i was planning to start a new one in the build section..