Topic: Stuck!!! This is my first street bike CB750F, and I don't know what to do next.

[Hondalubr]

Well I have gotten it running again (with your help with the carbs). I have located and ordered the new muffler, right hand morror, and air filter (with your help finding parts). They are on the way! I changed the oil. I put on new tires (Dunlop K70's) front and rear last night (found the right brand and series tires using a link in the FAQ's). I bought them here locally from Mach 1 motorsports they have a web site at www.mach1motorsports.com. I will post a review of their service in a new thread.
I installed the tires and now have a squeeking noise when braking. Sounds like the front. I know what I need to do for that.

I guess my question is:
1) What should I do next?
The tank needs work. The clear coat is bubbling at the graphics, and there is some scratches on the tank where I dropped it while I was trying to work on the carbs.DOH!!! There is a small dent as well. That was there before I got the bike.
1A) There is a sound I cannot describe coming from the engine at all times while the engine is running, I don't know what it is supposed to sound like. It may be normal, but I don't know what to do to find out. It also has a miss durring warm up that goes away after about 10 minutes of warm up. Boy! this is a cold blooded individual! It takes her about 10-15 minutes to wake up. (I guess it takes after it's new owner. It takes me a while to wake up too! A few strong cups of coffee usually does the trick!)
2) There are some tiny little rust dots on the rims.
3) The aluminum parts are oxydized.
4) The motor paint has worn a bit near the footpegs.
5) The chrome is all in good order, maybe just needs a little buffing to clean it.
6) I weigh 275 Lbs and once in a while a large pot hole makes me bottom out especially when my wife rides with me. Should I replace the rear shocks?
7) The registration is from 1992 in Washongton state.
8 ) I cannot get into a rider course to get my license until sometime in mid November.
9) I live nearly dead center between Sacramento and San Francisco California off of I-80 and would like to meet others nearby with bikes like mine so we can spin wrenches together or whatever. Is it to soon to look for someone as I can't yet ride my bike except around the block?

Signed,
Looking for some guidance!
Hondalubr!

[Buffo]

what year is your bike?

get a shop manual...Clymers suck

adjust your inner brake pad

It is hard to talk about a problem that cant be described...have you adjusted your valves...synced the carbs...adjusted the cam chain

the rear shocks sucked right out of the factory...do a search in here on "rear shocks" and make your own desision

[Hondalubr]

what year is your bike? ---->1978

get a shop manual...Clymers suck---->On order... I forgot to put that in above. Takes 4 weeks as Honda prints therm when ordered. Ordered it on Friday 9-16-05

adjust your inner brake pad ----> Will do that as well as remove everything and clean the calipers and pads up with a wire wheel and repaint and add that silicon stop squeel to the backside of the pads.

It is hard to talk about a problem that cant be described...have you adjusted your valves...synced the carbs...adjusted the cam chain----> Not yet, was waiting to do that when I get service manual. Unless I figure out how to do it right before it arrives.

the rear shocks sucked right out of the factory...do a search in here on "rear shocks" and make your own desision---->Will look into that! Thanks!

The answers are after the ----> above.

[Buffo]

I have a K8 and have put a lot of time into my carbs...you  should do a search on "carbs"...I have a lot of posts on this matter...so do a lot of others...the more "in tune" I got my carbs the less cold blooded it became

JTB will sell you a copy of his shop manual on disk if you ask him

[Quail "Owner of the comfortable k8"]

I pull the choke, kick it once. It starts, stumbles then comes up to 3000 rpm, I bump the choke down 1/3 and when the idle hits 1000 I drop it in gear and go.  I push the choke 2/3 in in 1/2 mile.  I mile later I feel it start to stumble and bog down, I turn on the petcock and pound on my helmet calling myself names.  I now shut off the choke.  When the carbs are right it runs nice and that bolt bucket that lives inside with the cluch is quiet too!

[Einyodeler]

Download the K8-F3 manual here

http://www.sohc4.us/forums/index.php?topic=426.0

[scondon]

        I've been pulling down some heavy hours at work lately so there hasn't been much free time. That should change in a week or so and at that point you are welcome to come over to Oakland (about 20-30 minutes further than Vallejo where you picked up your tires). I've just finished restoring a '78 and would be happy to show you the tips and tricks I have learned while doing it. When you get your liscense you can bring your bike down and I can help you assess what work it might need.

        9 questions is too many to answer at this hour   But I will say that some new shocks will definitely improve your bikes handling. I'm about 240 and even when I adjust the stock shocks to the top notch it can still get a bit "swimmy" on bumpy turns. The "new" bike has Progressive shocks with Heavy Duty springs and the difference is very noticable. Cost is around $200 new.

[Hondalubr]

Wow! Thanks guys. I just read about half of the shop manual in about the last hour and a half. Boy, time sure flies when you are reading a good book! LOL Thanks Ein!

Hey Mr. Magnifico LOL
I have read a lot of your posts on carbs but didn't see that they would cause what I am hearing. I am however going to follow your advice and work on those things you mentioned before as well as carbs.

Quail,
You said "I bump the choke down 1/3 and when the idle hits 1000 I drop it in gear and go." How long does it take to get down to 1000 RPM? Gotta love forgetting to turn on the gas "eh? LOL Been there done that on other bikes I have! He he. Not good when your climbing this real steep hill at about 50MPH and about 3/4 the way up and bleeeeaaaah! No gas! Done that too! That one kinda hurt. The hill was too steep to begin with. I was showing off for my 17 yr old son to see how good dad can ride! I got back on and went up the sucker tho after turning on the fuel and restarting the bike at the bottom of the hill... That was just to prove it to myself I could do it! As Honda says: "Stupid hurts!"

Scondon,
That would be great. I could even bring my bike if that would be ok with you. I have a trailer and tie downs. Wouldn't be a problem as I am used to pulling the trailer with my off road bikes in it out to Prarie City and beyond. I can't wait to see your bike and learn something in the process. I was down in San Pablo all week putting in long hours myself! One of the Mobile home parks had a break in one of their cables and I had to get it fixed all by myself. Got it done Friday at about 3:30PM or I would have been there today too!

Thanks again guys!
Hondalubr (Mike)

[TwoTired]

1A)  Miss during warm up possibilities.  Carb synch, ignition, carb dirt, carb adjust, Compression unequal accross cylinders.
The cold bloodedness is probably exacerbated by the hole in your exaust. The loss of back pressure has the effect of leaning the mixture and you are compensating with more and longer duration of the choke.
Your new exhaust will have different backpressure characteristics, too.  Good possibilty you'll have the rejet and readjust the carbs for that.

2)  0000 steel wool on the chrome.
3) remove oxidation with abrasive (No steel on aluminum), polish or brush and recoat with clear or black paint.
4)  repaint
5) okay
6)  Perhaps.  Did you crank up the preload on the shocks all the way?  Probably more weight than Honda designed for.
7)  Shouldn't be an issue with DMV registration if you have and old title and bill of sale.  They want to feel reassurred it is not stolen.
  Practice off road.  Or, borrow a smaller bike and take the DMV tests with that.
9)  Are you nearer the Nut Tree airport or NAPA airport?  I can fly in for a one on one.

Cheers,

[Hondalubr]

Hey Two Tired,
You would fly in? How much would that cost me? I am not sure where Nut Tree airport is. I think it is in Vacaville? If it is that would be closer to me. They have everything named Nut Tree over there. I live right off I-80 at North Texas. It is the furthest eastern exit of Fairfield.

I just read your info and your in Milpitas. I was down there this past week as well for work. Dixon Landing rd. Friendly Village Mobile Home Park is one of the 11 parks that I do Cable TV service in. I could pull your way as well if thats more convenient for you.

Let me know when and where (has to be a weekend) I can't take any time off right now.
E-mail me your phone number and I will call you to work out the details.
Have a great day,
Hondalubr (Mike)

[Quail "Owner of the comfortable k8"]

Quail,
You said "I bump the choke down 1/3 and when the idle hits 1000 I drop it in gear and go." How long does it take to get down to 1000 RPM?

5 sECONDS

[BobbyR]

The oxcidized Aluminum can be cleaned with a wire brush and a drill. Use thin ones to get in between the fins as best you can. The cases should be sanded with finer grain paper. Then you use the nasty red rubbing compound on a drill bonnet to get them smooth. You can use that on the chrome pitting also. Then use the white. If you want them really nice you then use jewlers rouge and a wheel. They will shine. If the noise gpoes away when you pull in the clutch, it is OUR secret sound that no other company can duplicate and is normal. Your tank can be repaired many ways depending on the size of the dent. Decal kits can be bought and they look great. My advice is to clean up the mechanicals and safety items first. Get White off the cases ride with pride and then go after the tank. Welcome to the SOHC family!

[Hondalubr]

I attacked the chrome and points today. First the Chrome. I found the need to take some parts apart to get into the nitty gritty little spots. Time didn't permit that today so I just shined what I could get to with a cloth and some turtle wax liquid chrome cleaner. Man alive, the look was good before I did it and now... I can hardly believe my eyes. It looks like a completely different bike now! Even what I thought was shiny was no where near what it look like now. Then I tackled the points. I downloaded the manual... (Thanks again Ein!) I printed the pages I needed for thew timing and points section and got to work. I followed the directions exactly and when I was done I heald my breath and pulled out the choke and let 'er rip! She started right off. My low Idle miss was completely gone. I lowered the choke to about 3/4 and let it run at 2000RPM for three to four minutes and hopped on and turned off the choke. It idled great at about 1100RPM. I took it for a test run. The low RPM excelleration was night and day. Before it seemed to bog a bit then kick in. Now it was ready right from idle up and all the way through 7000RPMs. 3rd gear was at 75. What a RUSH! I then slowed and just cruised for about 5 miles. It was the best feeling. I didn't feel embarrassed a bit when I rode by some people walking in the neighborhood like I had before because the bike sounded crappy. Now it sounds like a well tuned machine even with the exhaust leak it isn't obtrusive. I sure can't wait to get the new muffler on and see what it is going to sound like.

You guys have been great and the most helpful bunch of ppl I have ever run across on the net! You really do meet the nicest ppl on a Honda!
Thanks again!
Hondalubr (Mike)

[Hondalubr]

  Well, Scondon was right when he said it would be great to see the shiny new parts arrive at my door. I was so excited when the UPS man rang the bell, I almost blew off work to put the parts on. Well I did install the new mirror right after tearing open the box of goodies from Old Bike Barn. I did go right back to work as I am behind a deadline to get a project done right now. As soon as I had worked my 8 hrs though, I was right out the door.
I installed the new muffler... I had to cut a slice of metal out of the header tube to make it fit. The universal pipe I bought was supposed to fit on the outside of the header, but the header was too big. I had to slip the muffler inside the header and install a "ring" clamp to tighten it down. Worked like a charm.
I put in the air filter and then fired it up.
It sounds absolutely Fantastic! It is so quiet yet rumble voiced I could hardly believe my ears. I turned the choke off within a minute and she stayed running for the first time since I got her started. Usually I have to keep the choke on for 10 to 15 minutes the first time she is started for the day. I hopped on and rode for about 10 miles when all of a sudden there was no power and I had to give it almost full throttle to keep it running. Then I realized something. I bet she is out of gas! She was! I turned the pitcock to reserve and she leveled right out again. Phew! My heart was breaking thinking that there was something more seriously wrong. I cruised another 6-7 miles and then headed for home. Wow, What a ride. It is just as smoothe as silk the way she is running right now.
  Oh heah. Now I can hear well enough to figure out what that mystery sound was. With the muffler leaking like it was, it was nearly impossible to tell where it was coming from. I found out that it is the clutch. It sounds like a bingo machine filled with nuts and bolts while idling in neutral. Then I pull the clutch and it almost completely goes away. Is this normal? It don't sound like it would be normal.  is adjusting the clutch hard to do? I haven't read the manual regarding this topic yet, but I will, before I even think about starting on the project. Are there any special tools required to do it Any hidden obsticles or quick tips that I should know about before hand?
As always your replies are appreciated!
Thanks,
Mike

[scondon]

    Congratulations on a job well done,Mike. Keep it up and if you make it down to Oakland it will be for RIDING, not WRENCHING Bike looks pretty sweet, I bet you're enjoying that new found performance.

    The only "adjustment" I know for the clutch is the cable tension. One next to the clutch lever, and one down by the clutch cover(14mm,12mm locknut, 10mm adjustment screw). This hasn't done much to quiet my clutch rattle so I hope someone answers your question. Search this site for "clutch rattle" as the topic has been covered a few times. This rattle is normal for these old bikes but I'm ready to replace all the disks in mine as it accounts for 80% of the noise coming from my bike at idle. It's louder than the Kerker exhaust, no lie 

[SteveD CB500F]

The clutch rattle is largely caused by uneven power pulses from the engine, which in turn is caused by unbalanced carbs.

Once you've done a complete tune up, get some vacuum guages and balance the carbs.

Before you ask, I recommend Morgan Carbtune II. Bought mine from eBay. They have steel sliders in place of mercury. Search on "vacuum guages" or "Morgan Carbtune" to see the volumes of discussion on the options.

[Hondalubr]

The only thing I haven't done is to check the valve adjustments and sync the carbs. This bike only has 12,500 miles on it. Basically brand new; I didn't think so much would need to be adjusted. "It was running really great, better than my Harley, when it was parked" said the PO. How would so much have become so out of tune while sitting in a warehouse for 13 years? Or is it the nature of the beast to have to tune these so much? Also, it sounds so good now other than clutch noise. Is it going to run even better when I have done the valves and carb sync?

Mike

[SteveD CB500F]

All POs say that...   

If you've fiddled with the carbs at all they will need syncing.  Have you cleaned them?

[Hondalubr]

The PO is my boss who gave me the bike. But yes I did have to clean the carbs... twice! I didn't get the slows clean the first time. But what about the valves?

Mike

[SteveD CB500F]

If you've had the carbs apart to clean them then they will require a resync.  And you'll have to do this every time you take them off....

[Hondalubr]

Do you think I will need to do the valves first or no???

[SteveD CB500F]

Yes.

The carb balance should always be last.

[Hondalubr]

Is it difficult to adjust the valves The only valves I ever adjusted was on my first car in 1983. It was a '69 Toyota Corona 1900. It took me hours to get them right, and oil was spitting all over the place because the adult who helped me told me I needed to do it with the engine running. What a calamity that was. I don't want a repeat of that. I will follow the manual on this turn, but are there any pitfalls to watch out for?

[SteveD CB500F]

It's not difficult, but you will need a set of feeler guages (2 and 3 thou) that can be bent through 45 degrees.

There are threads here about various special tools that you can buy to "adjust the screw while holding the locknut" but I've never found that I need them.  You will find a way of judging how much the gap will shrink when you tighten the locknut.

Just remember - too loose is only noisy, too tight may burn (or bend) your valves.

[Hondalubr]

Thanks Steve! I will try it tonight. I have a new set of feeler guages and will work on it aftert work. About the Sync Guages... Do you think it possible that a bike dealer would have them in stock? I looked while at Mach 1 Motorsports last week, but they only had the mercury kind. They had 2 sets one for 44 and one for 69 USD. I don't like the idea of working with mercury. Any thoughts? Otherwise I will just get what you recommended.