"The Apartment Build" 73 CB500four

[dentoncafe]

This is how I got the bike. Off of craigslist with clean title.
It turns out the body kit on it is a Tracy. The front wheel was flat, the wiring was a complete mess, but the engine ran. The carbs were off of a 77 Suzuki GS550.


After some cleaning up and assessing what I had, this is how it sat. I live upstairs, and my neighbors were kind enough to allow me to store it in front of their place under the balcony. I stripped the sticker, and rebuilt the Suzuki Carbs, however they did not have an idle adjustment. I did some research and just decided that getting the original carbs would be an easier, safer bet.

After some more research, I found a local buyer for the body kit. I traded it for a CB500T tank that was lined and ready to go. I got side covers, the original carbs, a wiring harness, and some loose odds and ends. I should have asked for cash too in hindsight

After rebuilding the carbs and spending days on the wiring, I got a cough from the bike. A couple more kicks and a new battery and she was alive! But there was another problem now, the clutch was stuck. After rocking it back and forth it came undone. I did a victory lap. It pulled VERY hard.

So I hated the seat and painted the tank, got a headlight and rewired it again. I needed a new clutch basket and air filters.

I hit up Dime City and got some much needed parts. filters, a seat, clutch springs and other odds and ends. It was running great but it needed new tires pretty bad.

I had my buddy Ryan come by and help me with the clutch and we replaced the worn out springs with heavy duty ones.

 

[dentoncafe]

SO the major problem that came up on this build was the drivetrain. The chain on this guy was insanely huge!

new sprocket on the left and old on the right both are 15T

The problem was the chain clearance and the clutch pushrod. It was eating it away and causing a safety concern.
So I ordered a new CB500 34t sprocket. its on the left and the old 45t is on the right. Turns out it does not fit the hub.

This is how it is at this time in the story.

After more research, I got some interesting information on the wheels. The front wheel is off a 76-77 GS1000 and so is the rear rim. However the rear hub is off an EARLY CB750. the rims are aluminum. SO i hit up my local friend John and he had a spare sprocket and chain I could use. I also ordered tires while I was at it. I got a Challenger for the front and a 712 in the back.

So I got a call from him that we were going to wrench at his place today.
Old rod and new push rod

adjusting valves

progress!

I didnt want to pay the tire mounting fee so we did at his place, these tires were OLD

Thats his restored CB750

 

[dentoncafe]

So it ran beautifully afte that, we sync'd the carbs and i drove it for 50 miles.
After that the air restrictor on the can fell off. vibrated out. Can't find it. I stupidly kept driving it and it just got worse after that. I did a compression test and found them to be under 100psi and none of them within 10psi of each other. More research. I had to pull the engine and replace the rings after a confirmed leak down test.
Draining Oil and unbolting engine.

My workstation

It begins

Tons of buildup, clean on the left

more pics

Annnnnd the valves...

got parts

CLEAN VALVES!

lapping the valves

Back together after 3 hours, i swear that spring tool is a pain to work with

cleaning the mating surfaces with brake cleaner and inspecting for major pits

 

[dentoncafe]

putting the pistons back on with new rings

getting the timing right

back in one piece!

exhaust collars clean on top and rusted out on the bottom

motor mounts, clean on the left

BACK IN THE BIKE!

Ok now here is where it sits. After some more research, I found out that i should have checked the ring gaps....
I assumed they would just work and threw them in there, I have not started the bike yet and will be pulling the engine back upstairs to tear it back down and check the gaps. Ill keep it updated as much as possible.

 

[Rich Ard]

Looking good. Though that Tracy was killer

Did you hone or measure bore while you had the top off?

 

[Islandstar]

Looking good..that was 3 hrs well spent!!

 

[dentoncafe]

I did not hone the cylinder, it was in mint shape, I pulled the motor again yesterday afternoon, my roommate andy helping me drag it up the stairs...

I checked the ring gaps and found them to be all within the limits, I readjusted the valve clearances and threw on the carbs for show

I just put it back in the bike today and did some compression tests. I must recommend that NOBODY buy any harbor freight diagnostic tools. THey are pure crap. I got 110psi in each cylinder, so its all consistent and I also read that most of them are off by as much as 60psi. Only took 4 kicks to get up to 110psi so Iim confident that the compression is spot on now. I returned the compression tester and timing light and instead got some much needed oil and multimeter tester ( I know I said their tools are bad, but I have had no problems with my friends tester).

 

[03rangerxlt]

Love it! Sad to see the old body kit go though. For some reason I really liked it without the stickers.

 

[dentoncafe]

OK so i fired her up today and it runs, well sort of...

I rode it around the parking lot and did a full throttle test, still low on power

#4 isnt firing, the pipe is warm but not hot like the other three so it isnt timing. I checked the valves, they are good, I checked the spark, it has one. So would it be the carbs? I just rebuilt them like a week ago.

 

[dentoncafe]

Also it will die if i pull the plug for #4

 

[SONICJK]

Also it will die if i pull the plug for #4

If number 4 isn't running it certainly shouldn't die when you pull the plug?

 

[coyote13]

Bringing this over from the facebook conversation: aside from the obvious compression test that's needed, what does your plug look like on #4?


Edit: Also, how long did you have it running? You might need to let all of the parts get seated before it'll run just right.

 

[dentoncafe]

ALright so here is how i fixed the problem.

Did NOT want to pull the motor again so i did a some tests.
Switch the wires on 1 and 4, still no change, then switch the plugs and BOOM, it was the damn plug. I got fresh plugs in now and it fires on all four. Still down on power, Ill up the jets to 110 from 100 and go from there. any suggestions on carb settings for a 4to1 exhaust and pods?

And before you get on me for pods, I have no choice on this bike, all the welds are gone, and I do not have any mounts for the original airbox, believe me I would have gone the airbox route if i could have, but its too expensive for now. This is a frankenstein bike. The only part i dont know about is the swing arm, its too wide for a cb500.

After it runs perfect, Ill need to locate a new rear axle and it will be perfect, also does anyone have side covers? its ok if they are cracked, but not in too many pieces for a 500four

 

[dentoncafe]

now 1 and 4 arent as hot as 2 and 3 pipes, timing?

 

[wowbagger]

The cb500 carbs are really forgiving. My '71 cb500 has stock jetting with pods and a 4 into 1. It runs great with #100 main and #40 idle jets.

 

[dentoncafe]

I'm having trouble setting the timing, anyone know of a good guide? I can set it for 1 and 4 but isnt it only supposed to make contact again on the F mark? I'm lost on timing

 

[wowbagger]

I use the service manual. It gives a nice step-by-step:

http://minus.com/lbhLYiWZunqkj1

I've also done the following trick to find TDC:

pull the spark plug from 1 or 4. insert a straw into the spark plug hole. as you turn the crank shaft watch the end of the straw. When it raises as high as it goes but before it starts to drop again then 1 and 4 are on TDC.

Also, this site is for a 750 but it still walks you through the process:
http://www.hondachopper.com/garage/carb_info/timing/timing1.html

 

[dentoncafe]

Had my buddy come by and help me out with the timing, it was WAY off, number 1 and 4 would not fire at all. We trace the problem to the wires, The wires were not making good contact, now all of them fire and it freaking screams. But it died a couple minutes later, I think it was the battery so it is being recharged right now. i soldered the wires back up and hopefully it should all run fine now. Just need to resync the carbs and get the timing spot on.

How she sits right now

 

[dentoncafe]

I have recently replaced the points and wired it up temporarily and have been driving it around town for the past week with no problems. I turned the mixture screws to 1/2 out from seated and now it idles MUCH better without a chance of dying. I just need to resync my carbs and rewire the harness so it can ride in the rain without dying of a short lol.

 

[Tews19]

Man you get some serious work done....

Side note, whenever a pipe is not as "hot" as other pipes the first to do is check for spark.... Then fuel... Your wiring harness looks pretty crispy... Is it hacked up?? I bought a used one on Ebay for 35 shipped a few weeks ago. A solid non cut up harness will save you time and less headache.