Topic: Helllo,New member, probably same old common problems...

[AntiRiceCRX]

Hey everyone, i have been Given a 1972 CB500 Four with 4,300 miles on it. It looks nice except for the rusted chrome peices and just lots of corrosion since its been sitting for twenty years near the beach in a shed. The carbs were extremly gunked up with crystalized gas and corrosion so i cleaned them and installed a some oem carb rebuild kit. I put it all back together and it still runs like crap. It sputters, surges, and stalls. It will be all gurgling and popping while accelerating and all of a sudden blast off and sound nice and crisp, then it will go back to sputtering and gurgling, when u turn off the choke, u hear tons of air being sucked in(no box or filters) and it dies. It has some drag pipes(4-2 with one pipe on each side) and from the right side pipe u can hear it making a poping noise the whole time ur accelerating, it will idle nice and smooth as long as u keep the rpms up. Should i just put some other carbs on it to see if my carbs are the problem?
When i got it

The bike as it sits now

[Noel]

Wow, that's a really nice bike. I wish people would give me stuff like that.

Anyway, the bike needs a complete tune-up, which includes:

Valve adjustment
Cam chain adjustment
New spark plugs
Fresh oil and filter
Breaker point cleaning or replacement, along with a gap check/adjustment
Ignition timing
Air cleaner service, which probably means replacement

And there's a real chance the carbs need synchronizing too. Certainly if you unracked them during cleaning.

And finally,you might have to consider the possiblility that those carbs aren't yet squeeky clean inside. (They can be difficult to get perfectly clean.) There's a fairly easy and effective method for cleaning without dismantling, if you want to hear it.

After you get through the laundry list (It's all pretty simple, actually. Just takes a bit of time, and any of us here will be happy to help you through it if you need.) the bike should run like a top. Then you can get into all the fun jobs like cleaning the inside of the fuel tank, removing rust from, well, everything, and so on.

Welcome aboard!

[Noel]

Oops; just realized that you don't have an airfilter to service, which is part of the problem. These bikes can be made to run well with an open pipe and no air filter/s, but it takes some work.

One of the easiest things to do to make the bike easier to tune is replace the airbox or at least throw on some pods.

[AntiRiceCRX]

so how do i get them squeeky clean, i blew air through all the holes i could find and just replace the peices that came in my kits(i know near to nothing about carbs except the general idea of how the venturi effect works lol) I was planning on just taking it to a shop and telling them to make it run. I have new points and condensors, i need a petcock and fuel cap(the locking peice was broken by my little brother). Where did u get your fuel tank and cafe seat? That is awesome, i made my own little fairing with a peice of metal and a peice of plywood covered in foam for my seat haha. looks okay tho.

Heres the story for how i got it for free. My uncle and his lifelong buddy when and bought matching bikes, they were racing on the interstate a year or two after buying them and his friend was hit by a car merging over, he wrecked and died instantly and my uncle was terrified of riding or even looking at the bike, he never rode it again. and so when i saw it in the back of his garage and asked if i could have it i was shocked when he said YEA GET IT OUTTA HERE, I GOT THE TITLE IN THE HOUSE, YOU CAN HAVE IT. so me and my dad rented a uhaul trailor and towed it from NJ to SC.

[Noel]

Yeah, I got to take that pic down; everyone thinks it's my bike. The pic is stolen from the Swarbrick Racing homepage and it's my "template" as I work on my bike. You can get the seat and tank (fiberglass, though, not so good for road use) from AirTech. Dunno about finding an aluminum version of the tank; they can be had for the 750 but I've never seen one for the 500. You can definitely have one made, but it'll be a grand at least.

As for the carb cleaning, get yourself a bottle of Yamaha brand carb cleaner. Mix some of it up with gas; 4-1 gas/cleaner. Empty your float bowls -- the large dark colored screw at the bottom side of each bowl -- and then inject about 150 cc's of mixture down each of the two fuel lines. Kick the bike over a couple of times -- igntition off -- and let it sit for a few hours. Drain the mix, hook the gas tank back up, and give it a try. If it's still not good, repeat the procedure but let it sit over night this time.

This, BTW, isn't black magic or snake oil; it's the directions on the bottle, and it actually works.

But it won't cure all your problems either. After sitting all that time, it really does need a complete tune-up to have even a chance of running right. And with the open pipes and no intake resistance at the carbs, it's never going to be perfectly smooth, especially at idle.

[Noel]

BTW, go to http://cgi.ebay.com/ebaymotors/HONDA-CB350-CB400-CB500-CB550-CB550F-MANUAL-1971-1978_W0QQcmdZViewItemQQcategoryZ35591QQitemZ4636241393QQrdZ1QQsspagenameZWDVW and then send 'em (or someone, anyway) your $25. Unless you plan on having the shop do everything for you, rich guy, it'll be the best investment you make on the bike.

[AntiRiceCRX]

haha, im by no means rich, but i did have 4k saved up for a CBR600F2-F3 , but since i have this i could save that money and just get this thing running, im too busy between school(senior year high school, graduating in like 2 weeks), work, and studying up for the ASVAB so i can have my job of choice in the Air Force.

[Noel]

If you can figure out how to get online and join the SOHC group, you can work on your own bike. Moreover, you'd be amazed at the crap the shop -- not to mention the dealer -- can pull. If you're willing to take your time and learn how to do it right, you are your own best mechanic.

And man, four grand will go a LONG way toward making that 500 sit up and do tricks!

< edit > But hey, if you're not up to it, I'd be glad to relieve you of your "burden". How's fifty bucks sound? 

[AntiRiceCRX]

haha well, as good as 50 dollars sounds lol, with the bikes mileage, documentation, and condition , id say its worth alitle more than that-even if its not running. I still have the originakl owners manual, warrenty card ,and the original title that was given to my uncle in NJ when he bought it(which looks really weird since its from the 70's).

[csendker]

Also keep in mind that changing/eliminating the filter and/or exhaust will likely require re-jetting from the stock settings.  Don't know what jets you installed, but my guess would be a stock set unless you specified something different when you ordered. 

Look here for the stock set-up --> http://www.sohc4.us/forums/index.php?topic=5410.msg26534#msg26534

No filter or box will lean out the mix.  4-2 pipes (are not stock) will also lean out the mix.

And Honda4fun has loads of manuals that you can download for free --> http://www.honda4fun.com/man_officina/man_officina.html

[anparkinson]

I had the same problem with mine. I must have had the carbs in bits about 5 times until I found the problem. Turned out the idle jets were furred up. I could see through them so assumed all was fine. They should be 0.42mm dia so I got a 0.40 model drill and tried to pass it through. No way would it go. I re-drilled them with this drill until it was nicely loose in the jets and it ran like a dream. Obviously the idle jets play a major part in the mixture control even at higher revs.

[Caferacernoc]

You don't mention anything about ignition. Do you have consistant spark on all four cylinders? New plugs? When I have an intermittant problem the first thing I check is making sure all four exhaust pipes get hot quickly and evenly.

[endobendo]

Dude, your running condition is almost definitely the fuel mixture as echoed by some of the responses.  Get a filter on that thing before you run it much if you care about the inside of the engine.  Also, I'd highly recommend finding a stock airbox as these engines run good with them via pods.  As a note my 750F uses #105 mains stock with the box and needed #120-#125 with pods.  Without pods would require even bigger.  The jet sizing is real cool in that the #105 means the orifice is 1.05 mm.  So, if you got precision drill bits at a hardware store you can make your own jets in a pinch.  I figured I needed about a 13% larger jet when using pods.  The dirll bits used a different sizing, like #18, etc.  You can find converters online to figure out the bit size in mm.

Basically, I'd get the fuel mixture closer to normal before messing with too much other stuff unless it is something totally obvious like old points.

[grumburg]

Oh, to be a wide-eyed SOHC virgin again! I have an extra 72 500 complete airbox system with decent boots (but no filter) if you are interested.

[grumburg]

PS : See parts for sale. Chicago550 has an NOS filter.

[AntiRiceCRX]

when my uncle gave me the bike, i started taking off things i thought were unneccesary and selling them to this guy that works at the honda shop. I sold him my old factory seat(like brand new, was wrapped in some kind of cover) for $150 and the complete filter box for $50, but i would rather have individual pods and throw in some bigger jets, i mean cmon, im 18, of course i want it to be alittle faster! haha

[Noel]

I can't say for sure about the other SOHCs, but the 500s were a bit rich as stock. When folks tell you you HAVE to richen up your jetting, well, I don't want to seem disrespectful of any of the posters here, but... "your mileage may vary."

It WOULD be a good idea to put SOMETHING in front of those carbs, if only to keep rocks out of your engine.

You really, really, really need to give the bike a complete tune-up. Then spend some cash on pods or whatever floats your boat.

If the bike still doesn't run well enough to suit you at that point, then you can worry about jetting, ignition trouble shooting, etc.

But until you go through the standard tune-up stuff, you'll just be groping around in the dark and likely fixing stuff that ain't broke.

IMO, of course.