Author Topic: 1972 cb500 trials and tribbleations (Read 5149 times)

Quorthon · « **on:** May 21, 2009, 07:20:20 PM »

Here is my new project.

Just got the damn thing up and running finally today. Runs perfectly and I'm super happy.

It leaks a little out of the petcock. I pushed the brass fitting in as good as I could, but I think it may not be good enough. Did I do something wrong here?

Here are some pics:

And here is one of my roommates bein stupid on their bikes:

new2novas · « **Reply #1 on:** May 21, 2009, 08:23:10 PM »

could be the hose too, are they new hoses....use the macro feature next time to get a better close up, too blurry to really see whats goin on

Quorthon · « **Reply #2 on:** May 21, 2009, 08:29:55 PM »

Old fuel lines. I don't really want to mess with getting new ones back onto the carbs. It's a little cramped in there.

I'm not missing anything though? Just brass fittings into the petcock right? How do I get em tight into there?

Also, anyone know which line is the reserve? Right or left?

Quorthon · « **Reply #3 on:** May 21, 2009, 10:17:16 PM »

The front brake is dragging also. What can I do about that?

TwoTired · « **Reply #4 on:** May 21, 2009, 11:01:04 PM »

The brass tubes are press fit into the valve body. They shouldn't come out. You may have to dismantle the unit a tap them back in on the bench.

Using the right size tubing 5.5mm from a Honda shop should allow a leak free fuel connection and you won't even need those screw clamps.

Both the lines are main feed and get equal fuel once the carbs fill. The fuel selector chose either the bottom of the tank or an internal stand pipe as the fuel source and routes to both outlets equally.

Lift the rear of the tank to get better access to the hose connections.

Have you rebuilt the front brake yet? There is a rebuild walk through in the FAQ.

bryanj · « **Reply #5 on:** May 21, 2009, 11:03:15 PM »

Plenty of post on dragging front brakes to search for ideas, as to the fuel lines you need the proper clips or tight hoses NOT jubilee clips as they are to big. Also BOTH lines are both main AND reserve

Quorthon · « **Reply #6 on:** May 21, 2009, 11:26:52 PM »

Thanks!

I guess I will be getting new tubing and removing the petcock and tapping the fittings back in.

I will also rebuild the front brake.

I'll keep this thread updated as I'm sure I'll have plenty o' questions.

bryanj · « **Reply #7 on:** May 21, 2009, 11:31:57 PM »

I would also get a front fender (Original NOT plastic) as the inner brace stops the forks flexing independantly

Quorthon · « **Reply #8 on:** May 22, 2009, 11:24:46 AM »

Oh ok, that's why I have seen bikes with just the brace then?

Is there some trick to getting the fuel tubes on and off of the carbs?

Or do I just need magical leprechaun hands?

bryanj · « **Reply #9 on:** May 22, 2009, 11:49:17 AM »

New pipe, boiling water, forceps and luck

TwoTired · « **Reply #10 on:** May 22, 2009, 11:54:42 AM »

The hose nipples aren't supposed to come out of the fuel valve. With the stock hose, I just use a sturdy flat blade screwdriver tip to push the supple hose off the nipple (no twisting of the driver tip). You can't pull off the hose, as the tube shrinks in diameter when stretched. Conversely the hose expands when compressed over its length. The screwdriver tip compresses the hose, expanding it and making it release from the nipple barbs. You can alternate putting pressure on sides of the hose end to work the hose off the nipple. Use the two hands on the driver, one holds the handle end, the other pushes down on the screwdriver shank near the tip.

As I said before, you can raise the rear of the tank for better access. Open the seat, And push the rubber holder off the rear tank tab. Then raise the seat for more space.

Your, fuel lines aren't stock and may have been cut too short, or hardened with age, and that will make maintenance operations far more difficult than normal. If they are hardened, it may be why the nipples pulled out of the fuel selector, too.

Previous owners are very adept at torturing future owners.

Cheers,

Quorthon · « **Reply #11 on:** May 22, 2009, 12:36:13 PM »

Ok thanks.

I have the tubes disconnected from the petcock, tank and seat off. I put a dab of red threadlock on the fittings and tapped them into the petcock, so hopefully they are now secure.

What I am trying to figure out, is how to get the tubes off and on the nipples at the carb. They appear to have some type of clip on them there.

Here are the best pictures I can get:

I suppose I can get a flat head in there to push them off, but how do I get the new ones on? What kind of clip is on them there?

TwoTired · « **Reply #12 on:** May 22, 2009, 12:57:48 PM »

I have some large curved forcepts that make putting those on possible. The forcepts also can be used to remove those wire clamps, too. They aren't very strong those wire clips. Just enough pressure to do the job, on nice supple new hoses.

Wait till you find out those carb fittings swivel.

Kinda like threading a moving needle.

Yes, it can be done.

Cheers,

new2novas · « **Reply #13 on:** May 22, 2009, 01:44:47 PM »

i have a set of those pliers too, don't use em much, but when you need them nothing else will do

Quorthon · « **Reply #14 on:** May 22, 2009, 03:34:52 PM »

Haha thanks. Going at now. Hopefully some long needle noses will do, otherwise I'll head to harbor freight.

Going out of town for the weekend in a couple hours, so I'm trying to get this thing back together so it's ready to ride as soon as I get back!

Quorthon · « **Reply #15 on:** May 22, 2009, 05:01:48 PM »

Well, got everything together easier than I thought! Got er started up and running good, took a decent little ride for about twenty minutes or so.

Then got home, parked er for about 5-10 min, started er up again, ran good for a second, then just died.

Now I cant get it to start at all?

Backfires a little on the kickstart.

Doesn't seem too flooded, no fuel dumping out or anything, and I can see fuel in the lines running to the carbs.

I think it is running a little rich because when I try and choke it it bogs out immediately, even when completely cold. Could this be related to that?

TwoTired · « **Reply #16 on:** May 22, 2009, 05:21:02 PM »

Check the spark plugs for soot deposits on the center insulator.

Check the tank for contamination. Carbs need clean fuel.

Quorthon · « **Reply #17 on:** May 22, 2009, 05:25:09 PM »

This is the first time I have ran the tank since cleaning and coating it, so it should be good.

I dismantled and cleaned the floats and float bowls with carb cleaner a couple days ago.

I will check the spark plugs.

Any thoughts on the choke thing?

TwoTired · « **Reply #18 on:** May 22, 2009, 08:37:29 PM »

The order of work is important.
Cleaning the carbs before cleaning the tank, still allows the carbs to become dirty from the tank before it is cleaned.

Recently had some posts where the user was operating the choke backwards, lever down is off, up is choke on.

Did you clean the emulsion tubes in the carbs?

Look at the spark plugs. It is your window on combustion conditions.

bryanj · « **Reply #19 on:** May 22, 2009, 11:14:12 PM »

Couple of hours to get and fit fuel pipes on a 500----BOY have underestimated!!!

Quorthon · « **Reply #20 on:** May 26, 2009, 01:47:04 AM »

Quote from: bryanj on May 22, 2009, 11:14:12 PM

Couple of hours to get and fit fuel pipes on a 500----BOY have underestimated!!!

Huh?

So I got home today and the bike fired right up. I pulled the plugs and they were a little sooty. Wiped em off and put em back before I started er. Rode around awhile and everything seemed fine again. Once it gets hot it is hard to take off without killing it. Runs perfect until it gets hot. Then eventually it won't start at all.

I don't know what the emulsion tubes are, so probably not....

Let everything cool down then pulled the bowls off the carbs and hosed everything with carb cleaner. Put it all back together and it wouldn't start at all. Just flooded and dumped out the overflow.

What to do?

cb544 · « **Reply #21 on:** May 26, 2009, 08:03:39 AM »

Quote

And here is one of my roommates bein stupid on their bikes:

Nice look project! Got any more pictures of that bike on the left? Is that a Royal Enfield? and is that HER Enfield?

Brilliant!

Quorthon · « **Reply #22 on:** May 26, 2009, 01:02:57 PM »

Quote from: cb544 on May 26, 2009, 08:03:39 AM

Quote
And here is one of my roommates bein stupid on their bikes:

Nice look project! Got any more pictures of that bike on the left? Is that a Royal Enfield? and is that HER Enfield?

Brilliant!

Yeah, thats my sister on her Enfield, and her boyfriend on his 750.

After riding for a few minutes it gets hard to start from a stop without killing it. Had to keep kicking it and revving high to go.

Oh, the bike is also not charging correctly. It seems to get a charge from riding at higher rpms, but just enough for a couple starter cranks. Brand new battery.

number13 · « **Reply #23 on:** May 26, 2009, 01:57:24 PM »

Quote

Oh, the bike is also not charging correctly.

That is probably a big part of your problem right there.
These bikes will not run for long on battery alone. Left to sit
for a while, the battery will come back enough to start and ride
again, briefly.
How did you test the charging system?

Quorthon · « **Reply #24 on:** May 26, 2009, 02:34:48 PM »

Quote from: number13 on May 26, 2009, 01:57:24 PM

Quote
Oh, the bike is also not charging correctly.

That is probably a big part of your problem right there.
These bikes will not run for long on battery alone. Left to sit
for a while, the battery will come back enough to start and ride
again, briefly.
How did you test the charging system?

Haven't yet. Spose I gotta go get a multimeter and run through everything. Ugh.

News:

Author Topic: 1972 cb500 trials and tribbleations (Read 5149 times)

cb544