Author Topic: 1973 CB750 Custom Build on Hack A Week (Read 104172 times)

knottedknickers · « **Reply #300 on:** April 24, 2016, 01:08:35 PM »

Quote from: mystic_1 on April 24, 2016, 09:30:57 AM

Good thing you hadn't painted the tank yet, or fate would have dictated that the ratchet fly the other way and bounce off the fresh paint.

That, or the brake fluid would have spilled on it.

dumbquestions · « **Reply #301 on:** April 27, 2016, 04:38:07 AM »

Outstanding tutorials. Subscribed.

Dino · « **Reply #302 on:** May 01, 2016, 06:32:03 PM »

It's done enough to get inspected! I still need to put the data plate back on the frame then paint and install the emblems. I fired it up for a short ride around the cul de sac and it runs great! Hope to take it to a classic motorcycle show in Salisbury NC next weekend.

)

MickB · « **Reply #303 on:** May 01, 2016, 06:39:58 PM »

Dino just wanted to say a big thank you from Sydney re your video on the points gaps and timing, I watched it 3 or 4 times and applied it to my '73 CB500, it started first time, just like yours. I was amazed, surprised and wrapt it started.
It was a huge help, thanks mate.
I'm also nearly ready to get inspected and register.

70CB750 · « **Reply #304 on:** May 02, 2016, 04:18:46 AM »

End of an era

Congratulations!

evanphi · « **Reply #305 on:** May 02, 2016, 04:51:43 AM »

Dino's the man!

SOHC4 Cafe Racer Fan · « **Reply #306 on:** May 02, 2016, 08:25:07 AM »

Dino,

You know this one is headed for a BOTM nomination once you get the bodywork painted.

Dino · « **Reply #307 on:** May 02, 2016, 05:06:17 PM »

I attached the data plate this evening and sorted a few details. Tomorrow I'll stop by DMV and get the papers I need for inspection.

I have a few unidentified bits left over. Anyone care to comment on these and where they go on the bike? Bear in mind that I don't have any rear foot pegs installed due to the 4 to 1 exhaust.

grepper · « **Reply #308 on:** May 02, 2016, 05:13:17 PM »

D: cable keeper under headlight, E: holds carb drain lines at back of motor. B: seat hing, G: seat latch part. Can't recall the others

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Dino · « **Reply #309 on:** May 02, 2016, 05:16:03 PM »

If 'B' is a seat hinge then I have an extra because both of mine are installed. Same with the seat latch part. I though the others were hose and cable keepers but I didn't know where they went. Thanks!

JWExperience · « **Reply #310 on:** May 02, 2016, 05:20:19 PM »

B is a seat mount, it bolts to the seat and the hinge goes into the tube.
E bolts onto the center rear engine case bolt and I believe it holds the carb overflow tubes. Mine is unused and overflow tubes are off to one side to avoid the rear tire.
I have one D bolted to my lower triple to route either the clutch, speedo cable or both.
I can take pics for reference if you'd like. It's the least I can do, your videos are amazing.
I have boxes of leftover parts too, wouldn't mind donating something, pm me if you think of one or two you might need and I can take a look.

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Dino · « **Reply #311 on:** May 02, 2016, 05:24:48 PM »

Quote from: JWExperience on May 02, 2016, 05:20:19 PM

B is a seat mount, it bolts to the seat and the hinge goes into the tube.
E bolts onto the center rear engine case bolt and I believe it holds the carb overflow tubes. Mine is unused and overflow tubes are off to one side to avoid the rear tire.
I have one D bolted to my lower triple to route either the clutch, speedo cable or both.
I can take pics for reference if you'd like. It's the least I can do, your videos are amazing.
I have boxes of leftover parts too, wouldn't mind donating something, pm me if you think of one or two you might need and I can take a look.

Sent from my iPhone using Tapatalk

Thanks that helps.

I've looked at some pics I found on Google and now I know where to mount the cable keeper on the lower tree.

wowbagger · « **Reply #312 on:** May 02, 2016, 05:33:01 PM »

F looks like the keeper plate for the rear brake shoes.

grepper · « **Reply #313 on:** May 02, 2016, 05:43:40 PM »

Quote from: wowbagger on May 02, 2016, 05:33:01 PM

F looks like the keeper plate for the rear brake shoes.

That it dose.

I went out to my bike to see where the cable keeper mounted and someone beat me to it.

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Dino · « **Reply #314 on:** May 02, 2016, 05:55:33 PM »

OK I remember installing that. It's an extra as well.

Dino · « **Reply #315 on:** May 07, 2016, 09:47:56 AM »

Just got back from the first 18 mile ride on my fully inspected and licensed CB750! Seems to run ok but I noticed that the oil pressure drops significantly when it's hot. I have a liquid filled gauge installed in the common location, the oil gallery on the top right side of the bike, and it registers 30 - 40 psi at anything above 2000 RPM but at idle it drops to almost nothing. Now I have to consider the calibration of this gauge as well. It's a 0 - 100 PSI gauge so it may not read that accurately and lower pressures.

The oil light does NOT come on at idle. Key on engine off, the oil light lights up so I know that function as it should.

So here's a question for any of you that have a gauge installed. Is what I'm experiencing normal or should I be concerned? I'm running Rotella 15W-40.

MRieck · « **Reply #316 on:** May 07, 2016, 09:55:19 AM »

Normal. If it's pretty hot switch to a 50w oil

Dino · « **Reply #317 on:** May 07, 2016, 10:36:03 AM »

Quote from: MRieck on May 07, 2016, 09:55:19 AM

Normal. If it's pretty hot switch to a 50w oil

Yeah I was thinking of running a straight weight oil as well. I just fired it up after setting for an hour and the pressure is back up to 40 psi at idle.

Thanks.

mystic_1 · « **Reply #318 on:** May 07, 2016, 11:09:43 AM »

It's normal for the oil pressure to drop a lot when the engine is up to operating temp, versus startup pressure.

IIRC the oil pressure switch is set for something like 7 psi.

How close to nothing is "close to nothing"?

My bike at startup makes something like 50psi at idle, maxes out at 70ish when revved, but when warm makes only about 15 psi at idle.

mystic_1

seanbarney41 · « **Reply #319 on:** May 07, 2016, 11:16:54 AM »

If your oil light is off, you know you have at least, in the neighborhood of, 5 psi. And is apparently all that Honda required at idle. Is your idle speed set around 1100 rpm? Don't be tempted to run a lower idle speed just because you can. 20w50 seems to be the magic number for environments averaging over 40 degrees. Rotella works ok, but you will notice the difference with a quality mc specific 20w50.

RAFster122s · « **Reply #320 on:** May 07, 2016, 03:14:47 PM »

Then there's the debate about adding ZDDP to your oil if it doesn't have it in sufficient quantity, most non MC oils don't, and only the better MC oils have enough.
Not that it affects your oil pressure.
Will a synthetic MC oil give you better oil pressure?

Dino · « **Reply #321 on:** May 08, 2016, 08:37:26 AM »

Out for a ride with my wife today. She's on her Virago. The CB is running ok but when I go WOT it starts to boot and pop around 6K RPM. my first thought I'd to drop the needle one notch because I'd to rich at to end. Opinions?

seanbarney41 · « **Reply #322 on:** May 08, 2016, 09:05:14 AM »

main jet

Dino · « **Reply #323 on:** May 08, 2016, 10:59:59 AM »

Quote from: seanbarney41 on May 08, 2016, 09:05:14 AM

main jet

I think you're right. I checked and remembered that I installed some 135 mains that I had thinking I would let it break in rich. I have a set of 120 mains I'll throw in and give it another go. The needle is set on the center slot.

I attached a pic of a plug chop test. Shut it down during WOT 6500 RPM. TOO RICH!!

SOHC4 Cafe Racer Fan · « **Reply #324 on:** May 08, 2016, 11:57:42 AM »

I had the same issue on my 550 when the main was too rich.

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Author Topic: 1973 CB750 Custom Build on Hack A Week (Read 104172 times)

JWExperience