Author Topic: 71 cb750 rejuvenation etc .. Not calling it a restore (Read 9204 times)

Salman_z8 · « **Reply #50 on:** July 13, 2016, 10:22:30 PM »

Different stages of assembly

Salman_z8 · « **Reply #51 on:** July 13, 2016, 10:23:33 PM »

My version of exhaust repair.

Salman_z8 · « **Reply #52 on:** July 13, 2016, 10:24:52 PM »

I like my pipes lol

Salman_z8 · « **Reply #53 on:** July 13, 2016, 10:27:02 PM »

Mostly together, looks like a motorcycle again

Salman_z8 · « **Reply #54 on:** July 13, 2016, 10:28:10 PM »

It runs

Salman_z8 · « **Reply #55 on:** July 13, 2016, 10:37:51 PM »

As stupid as it sounds, but there was only part that i did not go through throughly, since it was fine before disassembly, i figured what the hell right.
Just wanted to get it running.
Yes, the carbs.
And now i have issues.
Top end is fine, but idle is rough. Wont come below 1100rpm, and there is a little bit of hang coming down. Slight hang.
Jetting is stock. Everything is stock.
Air screw is at 1-1/4

I figured it could be the crappy beaten up points, and bad timing, since i was only going by ear. No timing light yet.
Ao i went ahead and bought basic pamco ignition, new correct plugs and new caps.
Still waiting on them.

Any other ideas .. ?
Is there a trick to install carb boots .. I keep thinking that carb boots might be leaking but i dont want to spray carb cleaner over fresh paint

you know !

So my easy part is done, now need some help.

Also i ordered baffles for the pipes, they are running straight right now.
I thank everyone for their patience as i kind of did bring this thread back from dead.

Salman_z8 · « **Reply #56 on:** July 13, 2016, 10:58:14 PM »

This is how she sits right now

hashvm · « **Reply #57 on:** July 14, 2016, 07:03:00 AM »

You're doing a great work man!

I'm following

-Hashem

mrbreeze · « **Reply #58 on:** July 14, 2016, 11:42:24 AM »

If all of the tune up items have been addressed...........a good carb synch will take care of the high/hanging idle.

Salman_z8 · « **Reply #59 on:** July 14, 2016, 01:22:44 PM »

Tappets are set at .002 and .003 inches for in/ex
Ignition timing is close, but not spot on. Still waiting for the timing light, and also the electronic ignition plate.
Carbs were fine when they were taken off, and carb boots are new.

Also waiting for the carb sync.

Any other ideas come to mind ?

Stev-o · « **Reply #60 on:** July 22, 2016, 06:19:38 AM »

You want the idle lower than 1100? I like it higher....

Salman_z8 · « **Reply #61 on:** July 25, 2016, 12:20:37 AM »

Ideally, i would like it around 800-900 .. But thats just me though.

Heres an update, installed the pamco ignition today, had the wiring all cleaned up.
So now i have three wires coming off the plate, and the ground off of the plate itself.
I can use the original points grommet.

Ignition seems to have solved a whole bunch.
Also put in new spark plug caps, and will be switching out the plugs too.
Got my timing light, and ignition is spot on now.

Now as i had said earlier in some post, that there was one part of this build that i didnt see a reason to go theough again was the carbs, which was a very stupid decision.
For some reason the PO had decided to ditch the original 120 mains for 110's.
That would explain why it was running hot, and the difficult cold starts needing full choke almost always.
So have ordered four 120's from the dealer.

Bought the wrong chain cover.
I have a very decent chain case for an early bike.
K0 i believe, if anyones interested, as the holes are too close for my use.
I am now hunting for a case for k1, again.

PM me if you got one and want to part with it.

Salman_z8 · « **Reply #62 on:** July 25, 2016, 12:21:51 AM »

Morgan carbtube ahould also be on its way.
I opted for that in place of the motionpro one.
Hopefully, that was a better choice.

Dunk · « **Reply #63 on:** July 31, 2016, 04:59:37 PM »

Looking great. Mine was originally that color. Looks like you're almost done.

754 · « **Reply #64 on:** July 31, 2016, 05:12:22 PM »

Are you talking about the chainguard when you say chaincase ?, i might need that earlier one.

Salman_z8 · « **Reply #65 on:** July 31, 2016, 05:14:25 PM »

Yup, chain guard

754 · « **Reply #66 on:** July 31, 2016, 05:21:51 PM »

I do have a 71 plastic guard. Somewhere.. But i think it needs a bit of plastic weld..

danyo · « **Reply #67 on:** July 31, 2016, 05:24:17 PM »

Second in line for chainguard if Frank passes which I doubt. He is hungry for K0 stuff

.

Sent from my SM-N900T using Tapatalk

Salman_z8 · « **Reply #68 on:** July 31, 2016, 05:34:23 PM »

See if you have the 71 plastic one, and pictures if possible ..
This one i believe is from a k0, i can post some pictures as well

754 · « **Reply #69 on:** July 31, 2016, 05:44:50 PM »

If yours is plastic and does not fit it should be KO, a shorter one..i am interested
The 71 looks like the later steel type, take me a few days to find it..will pm you when I do..

Salman_z8 · « **Reply #70 on:** July 31, 2016, 06:40:03 PM »

Sounds good.
The one i have is plastic, just the bolt holt spacing is a little too close for a 71.
I will wait for your pm.

Thanks

Salman_z8 · « **Reply #71 on:** August 03, 2016, 11:36:02 PM »

So i got the 120 mains in today, also lowered the float level a bit to get to 26mm.
Spark plug colour is now ideally tan. A very slight bit of idle issue, ( it still idles at 900) i think will be resolved after carb sync.
But there is another issue, that has been going on for a while, and now i need opinions on it.
I actually knew that i would have to dig into my oil pan, but had been avoiding that in the hopes of a miracle .. Stupid me.

My oil pump did get new orings and gasket during the engine build, but now, after the engine has run 10-20 miles and i come home to park, my oil tank is empty.
And very shortly after that the oil pressure light comes on.
This has happened 3 times now, and it becomes a pain to prime the pump everytime.
Why does it do that .. ?
The oil level was fine, and then suddenly the oil pump decides to not return any oil, and wet sumps.

Do i have any choice other than to pull the pump out ?
My engine is all nice, and clean and shiny lol and am really trying to avoid the whole gasket removal, cleanup, redo it all and the mess that cones with it.

Other than that its running pretty good, transmission is fantastic now.
Tappets are a bit noisy, probably a bit on the loose side, but i wanted to do atleast 2-300 miles before tightening.

Any ideas would be appreciated. My curiosity is about why only when i come back from a ride.
CycleX offers a rebuilt pump, has anyone used that ?
Their transmission was great.

mrbreeze · « **Reply #72 on:** August 04, 2016, 01:03:03 PM »

You will have to maybe burn a pan gasket but more than likely go back into the pump. Did you install a new stopper valve in the pump? If the tank goes empty.....where does the oil go? Is it going through the filter? Do you have a gauge hooked up to check pressure? The pan gasket will be the least of your worries if you starve out the top end for oil!! Carefully check if the stopper valve and relief valve are working correctly....installed correctly. I wouldn't even be starting it until you figure out where the problem lies.

Salman_z8 · « **Reply #73 on:** August 04, 2016, 04:52:04 PM »

Crap, was afraid of that.
Oil sits in the crankcase. The three times it has happened, it always happens when i come back from a 10 min ride and the engine is hot.
On a cold engine, cold start ups, and everywhere else its fine.
I guess i will collect the oil this time, and reuse it as it is brand new.

How do you guys lift the bike enough to get to the oil pan, as it would be pretty awkward from the floor.

No i dont have any pressure gauges hooked up, because i wanted to keep it absolutely stock. My logic was, if it was good enough for then, it should be still good provided everything works correctly.

Salman_z8 · « **Reply #74 on:** August 07, 2016, 05:15:21 PM »

So i have gona ahead and ordered a rebuilt pump, and gasket.
Will switch out once i get them, then will inspect the one coming out and see whats the deal with it causing the empty oil tank.
I would like to find a reason, or it will keep bugging me

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Author Topic: 71 cb750 rejuvenation etc .. Not calling it a restore (Read 9204 times)