My very first bike! 1980 CB750c

[Yuxc]

Like many of the people that I've seen post on here i got my first bike/first cb750c and i have A LOT of questions that i'm hoping will be answered over time/as i find more.

May i add from what I've read already searching for answers you all seem like a bunch of nice people and I'm glad i found a nice cb community :)

First things first I'm a 23yo heavy duty mechanic apprentice that hasn't ever been to school due to bullshit-ery from my company (not the point of topic) but i have about 3 years mechanical exp (all large locomotive diesel engines) and lack a lot of terminology/part names. (thank god for pictures!)

That being said i am really excited to (learn to) ride my bike and work on it myself. Like the title says i/my wife (600 bucks for my bike as 2 year anniversary gift....best wife ever!) bought a 1980 CB750c which seems if very decent condition here's the good and the bad (according to previous owner)

GOOD:
Forks just serviced with new fork seals (i cant see any leaks and forks in my no experience feel smooth)
New last season gel battery (I'm from Canada winters a bitch)
New last season tires (my buddy agrees they look brand new hes been riding a few years hes the one who rode it home for me)
Engine redone last season
Tank looks like there's no rust in it at all!
New seat
new sprockets and chain
my buddy says that when he was riding it it feels real nice sounds good has great power no strange vibration good braking
oil just changed (its actually still golden)

BAD:
Engine redone (even though its running i just hope who ever did it knew what they were doing!)
previous owner says carbs need to be tuned (engine redone but carbs not synced...?)
Engine either idles at 3k or dies at 1k (choke not engaged)
Right side panel missing (minor ill find one)
oil leak was a mystery but found out its coming from engine sprocket
1 exaust seal clamp(?)  was missing a nut but i put one on and snuged it evenly (not to tight dont know torque value if any)
float overfow nipples missing all hoses
crankcase blow by box (under battery housing) is just sitting there with no hose/plug
air filter houseing has a nipple at bottom that looks like it should have a hose (to blow by box?)


The reason I think the carbs need to be tuned is i saw fuel coming out of one of the floats when the bike was sitting turned off and on the side kickstand it was the one furthest from the kickstand (brakeside/right hand side .....#4 carb?) no big deal ill do the carbs my self I'm pretty sure i can tackle cleaning them syncing them i herd is a little more tricky

Oil leak.... its to my understanding the there is supposed to be a little bit of oil that comes out of the engine sprocket to lubricate the chain as you ride my buddy and i checked the dipstick with the bike dead and warm at a standing position and there was no oil on dipstick but oil is showing full when bike is on side kickstand) i downloaded the manual from the site and I'm trying to tackle all the maintenance myself but I'm dying to ride it (rode once only in first gear lol) but before i do i want to make sure me just jumping on it and riding isn't going to be causing me more problems from ignoring small preventive maintenance.

anyways been kinda wraped up in tinkering with my bike and need to spend more time with my awesome wife that got me it in the first place thanks in advance for any help you guys give me :)

p.s if i cant describe the part ill post pics with arrows and ill post pics of the bike in general for your viewing pleasure ;)

[TOOLS1]

Congrats on the new bike, and welcome to the forum. There should not be any oil leaking around the sprocket! Also the oil should be checked when the bike is straight up. Syncing the carbs is actually very easy. What is being done is, you are adjusting the carbs to where they all read the same vacuum. You will need a set of gauges though. I got mine from a seller on e-bay. Here is a link to one of his auctions. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&_trksid=p4340.m748&item=380360674131&viewitem=&_trkparms=clkid%3D1953719390561157 He used to sell them, for $52.00. I guess the price has went up. Still a good deal.
TOOLS  

[shinyribs]

I got mine last week.Still $52   $10 for shipping.    Worked great.Love the little choke-off valvesThanks Tools! Sucks they went up   glad i didn't hesitate

[shinyribs]

I'm new here too Yuxc. Only had my bike 2 weeks,never touched one before and already carb syncing is a breeze.I am in no way a master motorcycle mechanic.but with the help of the manual(you can it download here)and alot of help from Tools ( you da man!)and i got mine running great...i think. Super easy to work on.Don't be intimidated,you can do it.Have fun!!!!

[Yuxc]

Thanks for the link and confidence booster I really wanna get my bike running tip top but unfortunately I have my bike and landscaping(and a few other projects)to do so I'm trying to balance my time I think I'm going to have to order a countershaft seal to stop the oil leak all my leads point to it

[free2ride]

good luck on the oil leak. I think my leak was from the countershaft seal -- wherever it was from the mechanic [I wasn't about to touch it] said he had to split the engine to get it done -- mega-labour-bucks. he said that it was becuse the bike is an '80 -- a bit newer or older and it would have been an hour labour.

seems a PO had noticed a leak and had shoved/rammed a seal from the bottom with a screwdriver [causing other damage as well that needed to be repaired].

but this year -- THIS YEAR -- the bike finally runs like a charm [except for that possible starter thing].

[wes]

m new also, had my bike lil over a month. this is a great forum with some very good tech. support. post a pic of your scoot. DOWNLOAD THE MANUAL OF THIS SIGHT!! it sure helped me!

[Half-Caf]

I like all the black, and the muffler as well.. What kind is it?

[shinyribs]

Amesome!!Welcome to the forum.I am new to these bikes as well.You will learn fast as they are pretty simple to work on.Dont let syncing the carbs worry you,i was concerned about it and ended having mine done in no time.Takes longer to get the tools setup than it does to do the actual job.There is a link to where you can get the tools to do it here.I will see if i can find it for you.You can buy more expensive kits,but the ones i got are going for around $60 and worked really well.

You got a nice bike!and must have got yourself a pretty good girl too.Better hang on to both of them!

Good to have you!Have fun and good luck

[shinyribs]

Here is the link to the carb sync tool
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=290585212284&viewitem=&sspagename=STRK%3AMEWAX%3AIT 

[Piute]

 Welcome Yuxc
   Only been on here a bit myself but always learning ,congradulations on the bride and also the love she has for you shows by you coming together for a bike ,witch will keep you both even closer,even in Canada,
 Moved here from Wisconsin ,
   600 bucks and ride able well your ahead of the game in price and knowing if it will run,Mine didn't even start, 2 months ago when I got it,But looked to be in excellent condition at 250I've given myself till next summer to have her the way she should run and that is all day .>>Piute<<<N>>>Judose<<<

[Yuxc]

So its been a while since i posted/worked on my bike. I dont have a garage so she sat in the shed all winter. But anyways i finally tinkered around on her and got her to idle without choke at about 1300-1500 (im still nervous to set it any lower even though its supposed to be 1000 +/- 100 correct?), also when shes warmed up she can start without the choke . But anyways how did this all come about. Well it all started with putting a trickle charger on a neglected battery that sat in my shed all winter(i think i got lucky in the sense that the battery actually survived it). Okay, so she can turn over and run for a bit but sounds really angry that i spent all winter with the wife, i knew there was more work too do. Bought new plugs, was going to go with NGK Iridiums but i don't think they had my size so i went with standard D8EA's . Got oem paper air filter but found out when i switched out the k&n filter that PO had thrown out the metal bracket for original filter style, so i with the help of my wife, rigged up a new one which actually works quite well, its just a couple of small metal brackets lying in the shed that i got my wife to wire wrap together with a pull string made from wire to get filter out for change up. Bought proper o-ring for my front sprocket bolt that was missing, found out that i'm missing the damper ring still but i think i can manage without for now.  After switching out parts i decided to play with pilot screws on the bottom of the carbs. After first attempt the bike was running worse than the year before D'oh . Then when i took the tank off to better get a look at the carbs i realized that some fool who must have worked on them pinched a bracket for the fuel line that comes off the carbs in between the top cover and the i guess you could call it carb body on the number 2 carb! So i took it apart and got the bracket out and flatten the kink out of it with the back of a screw driver (most of my tools are at my work wich is about 40 mins away so i started getting a little primitive but not so much as to break stuff) any who i also found that the carbs are pretty fricken clean bonus on my part but i still decided to run a bit of sea foam threw her just to be safe. The fun part. I dont have my license yet but my buds took me riding last season (im able to with them kind of like a license parent/guardian lol) so convinced the wife to let me take a rip to make sure the sea foam runs through the system , right? lol Anyways took her for a bit of a ride i finished taking a turn and pulled my clutch to switch gears and she sputtered and died... so i pulled over and and put her in neutral clutch still pulled and tried to start. She had a little trouble but started up and i finished the rest of my little circuit and went home with no more problems. The funny thing is when i got home and im slowly bringing her through my fence my jeans catch on my chain link fence and rip my pant leg, so of course i go in the house and say i wiped out  So it was a pretty good day got my bike going pretty good played a trick on the wife and got to update my situation to you guys, sorry for the long read but its been a while since my last post and i just wanted you all to enjoy the good news with a bit of humor. Now i can start on some of the cosmetics...

[shinyribs]

Sounds like fun! Glad you got it going good.You are about right on that idle.I know the manual I have says 900 +/- 100 rpm.Yeah,not gonna happening.My stays right at 12-1300 rpm.

So,how did the wife like the "wipe out trick"?

[TOOLS1]

All right!
TOOLS

[LukeM]

great story, bro. Tell it again.

Such a good feeling when you get the machine working (doesn't mayer what kind of machine: bike, car, clothes dryer, computer, typewriter). Taking that first test drive... All senses firing, listening, smelling, feeling, and my favorite: the view from the front seat of a motorbike. No cage, no visits, no air bags, no seat belts... It blew my mind when I got my cb750 tuning the first time, and that test ride after 30+ years. Still gives me shudders.

Congratulations on getting it going. Now it's time to make it reliable, which means checking all the systems, and finding a good confection for parts and stuff. And making it pretty, of course.

Luke M

[Piute]

   Great to hear ya back ,
Long Honey moon,Still playing around with mine and it too idles at that 11-12.
   Get yourself some mo pants no shorts aloud

[rrgunslinger]

Cool read! Glad things are working out good for you.  Took me 6 years of work to get mine going again.  

[Ganguskahn91]

Hey guys, its cool to hear other peoples stories about their bike :)
Im 21 and just picked up my baby a couple weeks ago.
It wasnt running at all, cost me $300 figured it was a pretty good deal.
ive never worked on an engine before so this is all new to me, but i have pretty decent reasoning and logic skills (as most men have :P)
so i was looking at the bike and noticed aq switch missing. looked it up and turned out to mbe the engine shut off switch. (pretty important switch huh? haha)
i couldnt get the switch at the moment, so i just combined the two wires and.... it turned over!
i couldnt believe it. i felt like a genius haha. so i was riding it a little bit, and realized it wasnt running like it should. it didnt have near as much power as it should.
so after letting it idle for a little bit in neutral, i felt the 4 seperate exhausts (not the greatest idea, but it worked) and i found out that 2 of my cylinders wernt firing!
apon a series of tests (different spark plug wires from different coils to different spark plugs) i realized one of my couil was cracked and not giving out power
so i replaced the coil in hopes of it fixing all my problems..
the good news: i had one more cylinder working
the bad news: it was running worse!! (and i totally burned my hand on the exhaust of the cylinder that started working xD)
ended up getting all new plugs and wires and coils and all the cylinders work finally!!
ohhhhh the power that the first ride gave me :DD such a thrill i tell you what :D


so finally here i am a little bit more informed about the bike, with what i think are some more serious problems.

first: when i hit about 4k rpm, the bike kinda bogs.. (my brother said it was vaulve adjustment problem but im not sure?)

Second: i have an oil leak from between my upper deck and lower deck. (thinking its a seal?)

third: it has problems starting =/ i got new battery, i just turned the idle from 3k to 1.5k ish but maybe it needs to be 3k to start? i have to sit there messing with the electric start and choke for a good while before it starts. (consequently the battery died and i had to push start it xD) any ideas?

and how fast do your bikes go? i have to be on the freeway to get to college, but i cant go as fast as the cars that are going 70.. (well my speedometer is broken so i dont kno really how fast we are going, thats just a guess :P)

hopefully you guys are still here!

here is my bike:

[Piute]

        Nice smile
                             What bike

  check your manuel and see were tach would be for the speed you wont ,there all different.

[Ganguskahn91]

thanks thats my fiance ;)
but what do u mean what bike?

and i havent gotten one yet =/ lol