Topic: Just bought my first bike!!! A 1978 CB750k

[brickman]

Alright....so obviously I am a Noob. I have been reading my manual, like it is the gospel. The bike hasn't been run in about a year and a half. The engine is seized, so the kickstart won't turn. I have removed the spark plugs and added some ATF to loosen things up. It has been working it's magic for a couple of days now. My question is...When, and if, I get the motor freed up, what other steps should I take (such as cleaning carbs and flushing fluids) prior to firing it up...Thanks and I appologize for such an elementary question

[Tripps]

Good luck my friend, I also bought my first bike this year, also a 78 CB750K, I hope you enjoy it as much as I do. Some tech wizzes here that can help you, unfortunately I'm not one of them.

[drones76]

http://forums.sohc4.net/index.php?topic=77533.0

Above is a link found with a quick search.  Learn to use it, it will save you a lot of time and cut down on repeat posts.  Also the manual you speak of, is it the service manual?  If not, search for that so you can get a copy.  

Welcome.  

[domer]

if you have the service manual, do the 3k mile tune up!

[import_tuner13]

bought mine a couple months ago, same exact bike!  isn't that exciting.  check the brakes, make sure that the front one doesn't stick. make sure the clutch works properly.  If the motor still doesn't turn you can pull the left side engine cover off (the one that says honda and juts out) and there should be  a large 23mm nut that you can try to rock back and forth to free it up. (worked for me!)  change the oil.  change the plugs (cheap) change the air filter, carbs are probably gummed up, PM SOHC Digger he can rebuild them for you (unless you want to do them yourself) what is the condition of the battery? PM me if you have any questions i had completely stripped down mine and just finished putting it back together.... waiting on a rear tire.  good luck!

[madmtnmotors]

I could have written this post twenty-five years ago when I bought my 78' 750K. Didn't have this forum to tap for info either. These machines are very forgiving and can take some abuse and neglect, fortunately for me. I bought mine as a "Trainer" and figured if I tore it up I wasn't out that much. I have not been able to ruin mine yet.

+1 on the 3K mile tune up. Oil, filters, brakes, carbs, battery, fuses, and to a lesser extent the clutch. If you can push it around in gear with the clutch lever pulled in then focus on just getting it running first, then evaluate the clutch. Check the sprockets for excessive wear AFTER you get it running but BEFORE you put any substantial miles on it.

There are some very good posts relevant to the carbs. Don't get carried away with tearing them down if you're not comfortable doing so. I believe one or more members offer rebuild services so you could start there if necessary. The carbs may only need "Freshened up" as opposed to a complete teardown.

http://oldmanhonda.com/MC/Rstart.html
http://oldmanhonda.com/MC/Rcarbs.html
http://oldmanhonda.com/MC/RHints.html

[kck3]

How long has the atf and acetone been sitting in the engine?  If its been a day or two, try and turn the bike over with the kick starter.  Don't kick down on it like you are stomping something, just a nice and easy kick.  If it feels like it doesn't want to turn over, don't try and force it-just wait a day or two more and repeat.  OR instead of using the kick starter you can put it in 4th gear and try rocking the bike back and forth.  This can free the engine as well.  Good luck and keep us updated.

[cookindaddy]

Brickman - hello!

That's great! I've got one too! Maybe we should start a 78 750K group on here?!

I figured that it was the final year that they made this model and after 10 years, Honda should have had it pretty much figured out. I haven't been disappointed except for things that PO's (previous owners) did to her. Now she is pretty much almost like new original and she looks and works GREAT!

I have no specific suggestions that haven't already been made. I hope that you have great luck with the bike. I can promise you that it is a blast to ride. It took me two years (including a complete rebuild) to get to this past summer but it was completely worth it. This summer alone I put on about 1500 miles on four really great trips. The bike is amazing! And dead reliable. And FAST.

Take your time and do the 3K tuneup as madmtn said. It will get you familiar with the basic stuff that needs to get done.

Put some pictures up so we can see what you've got.

You should have both the user manual and the service manual. Both have lots of insights and info for you.

[oldhondarider]

welcome!...  one bit of advise.  patience..patience..patience... nothing good comes easy... the trip will be long and may be full of obstacles... but it's a hella of a ride... ( the bike that is)...

[medic09]

Welcome!  Congrats on a great ride!  But where are the pics?  Thread's not worth anything without pics!  Definitely do all the 'regular maintenance' type stuff right off (after freeing the stuck motor).  Don't forget to check that the tires aren't cracked or otherwise unsafe.

As for carbs...well, maybe I'm just an old fart but working on your carbs used to be a rite-of-passage around here.  I can't do a damn thing else mechanically on a bike; but I can say I rebuilt the carbs!    As noted, yours might only need a little freshening up.  BTW, synching the carbs is no big deal if you have a good tool like a Morgan Carbtune.  If any of us live near you, they may have a carb synch tool to lend you.

The Honda shop manual for our bikes is very good.  I supplement it with a Clymer manual.  It won't take you long to go down the maintenance list and bring stuff up to date.

[bollingball]

Hey brickman you have come to the right place I also have a K8 the black one. Mine sat for 5 to 6 years and was also stuck. I like PB Blaster from any auto store like said rock it in 4th. If its just stuck from sitting it should break loose. I broke my carbs all the way down and think you should also I'm sure they are all gummy make sure to take out the slow jets I didn't so had to do it again 3K tuneup is a must do. Mine runs great I got it for $100. the guy was going to sell it for scrap metal price of $100. Local Honda shop wanted 5hr's labor to see if it would run I had just finished my 51 Chevy and needed a new project. The bike was coated with green mold after a good pressure wash I was shocked how good it looked. I drove it back to the guy I paid a $100 to and he offered $800 on the spot No deal. Just stick with it and you will be happy I'm sure. Lots of help here. cookindaddy I think you have a good idea 

[Stev-o]

Welcome! I just bought a '77, it's basicly the same bike and freed my stuck motor w/ATF & acetone.

Let's see some pics!

[brickman]

Hey guys...sorry for the delayed response. I have tried everything in my power to free this engine. I tried just ATF, I tried the 50/50 mix with ATF & Acetone, and i've tried dropping it into gear and hitting it with pb. I also discovered that someone had taken a cutting torch to the frame, to remove the left rider peg, and left two gaping holes in the frame. I bought this bike because I wanted to fix it up, and feel like I had a real vested interest in my first bike. I have come to realize that it is beyond my mechanical and financial capabilities.

On the bright side....Tomorrow, I am going to check out an '81 Cb750k that needs a lot less work, and is in a lot better shape cosmetically. The current owner said it needed a new CDI box and the carbs need to be synched. If that's truly all it needs...I'll be riding in no time!

I want to thank all of you guys who tried to help me with the '78

As far as the pics go...I'm going to put some up of both bikes, probably this weekend

Also, I may be posting the '78 on the fourms cl/ebay section

Once again...thanks to everyone who helped out...and hopefully I'll have some good news tomorrow

[Radam]

Hells yeah! Lets go pick up that 81 and get you on the road! Hopefully we can get your bike going by late March for the big SOHC4 rally!

[Radam]

This is the 81k

(I got this one to upload for you)

[brickman]

Here is the '78k