Author Topic: My first protect, Honda CB750G revival. (Read 7559 times)

Willh1983uk · « **Reply #25 on:** February 14, 2018, 12:45:29 PM »

It does look like it, I’ve not seen one of those before.

SOHC4 Cafe Racer Fan · « **Reply #26 on:** February 14, 2018, 01:47:08 PM »

It's a little reminiscent of the RS750 flat tracker.

seanbarney41 · « **Reply #27 on:** February 14, 2018, 02:03:47 PM »

basic honda race livery of the day

SOHC4 Cafe Racer Fan · « **Reply #28 on:** February 15, 2018, 10:24:46 AM »

Quote from: seanbarney41 on February 14, 2018, 02:03:47 PM

basic honda race livery of the day

Sean, do you know when Honda changed from red/silver/yellow (59-late 60s) and changed to red/white/blue (like the Bubba Shobert flat tracker)?

seanbarney41 · « **Reply #29 on:** February 15, 2018, 07:05:46 PM »

Quote from: SOHC4 Cafe Racer Fan on February 15, 2018, 10:24:46 AM

Quote from: seanbarney41 on February 14, 2018, 02:03:47 PM
basic honda race livery of the day

Sean, do you know when Honda changed from red/silver/yellow (59-late 60s) and changed to red/white/blue (like the Bubba Shobert flat tracker)?

not exactly...recently someone posted this, so earliest documented here would be about 1976?
world.honda.com/EWC/invincible/
certainly were fully rocking the red white and blue by the time they jumped into AMA superbike with Freddy Spencer and the V4's in the early 80's

I dunno what year/s Bubba rode that crazy 4 cyl. flat tracker. I do know it was not long before HD and AMA said nope in the rules.

Don't forget that there was relatively little Honda factory supported effort throughout most of the seventies.

SOHC4 Cafe Racer Fan · « **Reply #30 on:** February 16, 2018, 01:50:59 PM »

I heard that the bike that was the predecessor to the RS750 was a CX500 with the heads mounted 90 degrees so they resembled a conventional narrow v-twin.

Here's the Shobert RS750 getting loose.

10011651_653971681306739_4576906963973730960_o_zpsv3q9qy7x by Donald Leonhardt, on Flickr

seanbarney41 · « **Reply #31 on:** February 16, 2018, 02:15:55 PM »

oh right right...was thinking Shobert was the one who flat tracked a cb750 and when he had some success, got 4 cylinders promptly banned

Willh1983uk · « **Reply #32 on:** February 19, 2018, 10:58:38 AM »

Another quiet one tonight. Sorting through old parts that we got with the bike and building a stand for the engine. Hopefully this week we’ll have all the parts that came off the bike sorted and the brake calipers and bracketery ready for sandblasting. Also aiming to get the sump off and have a look around inside.

Stev-o · « **Reply #33 on:** February 19, 2018, 12:59:00 PM »

Quote from: Willh1983uk on February 19, 2018, 10:58:38 AM

... brake calipers and bracketery ready for sandblasting.

Vapor blasting would be the way to go with these. That is my plan...

Willh1983uk · « **Reply #34 on:** February 19, 2018, 01:04:53 PM »

What’s vapour blasting?

Stev-o · « **Reply #35 on:** February 19, 2018, 02:00:40 PM »

Quote from: Willh1983uk on February 19, 2018, 01:04:53 PM

What’s vapour blasting?

http://www.tsrvapourblasting.co.uk/TSR%20Vapour%20Blasting%20Services%20-%20Gallery.html

Willh1983uk · « **Reply #36 on:** February 19, 2018, 03:24:07 PM »

Happy with that, I’ll see if there’s anywhere local to me where I can get it done.

Willh1983uk · « **Reply #37 on:** February 20, 2018, 12:37:07 PM »

Had a real good evening on the bike, stripped the carbs down and put them all in de greaser to hopefully soak off all the crap that’s in them also removed all the surface rust from the muffler. Took the sump off and found the oil pump strainer blocked up with detritus. When we got the bike the kick start would not return once we tried kicking the bike up, we tried the kickstart today whilst the engine is stripped down and all was fine. I think it was the clutch that was stopping it returning due to it being all stuck together.

Willh1983uk · « **Reply #38 on:** February 27, 2018, 10:20:52 AM »

Continied the strip down today. There isn’t a B on the end of the camshaft. All engine covers that are taken off are being stripped so they’re ready to go to thee painters as and when. Going to try and get the head off next week

Willh1983uk · « **Reply #39 on:** February 27, 2018, 10:28:52 AM »

Quote from: Jerry Rxman Griffin aka MuthaF'er on January 30, 2018, 12:38:30 PM

77 F2 General Export set up for racing?

I'm interested in what has been done under that valve cover. Yoshimura Daytona cam perhaps? That would be an easy look and see. Perhaps it has a "B" stamped in the end of the cam? Going a little further what the head contains? Porting to go along with the larger valves? A measurement of the holes in the cylinders and what the top of the pistons look like.

Intriguing

there’s no B on the cam shaft that is fitted. We did get a used one with the bike which does have a B stamped on the end.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #40 on:** February 27, 2018, 10:52:06 AM »

Slotted cam chain sprocket? Can't tell much from those pictures. The "B" cam may be a Yoshimura Daytona cam. Much stronger than stock.

Willh1983uk · « **Reply #41 on:** March 06, 2018, 01:20:28 PM »

Another night on the bike stripping out the cam shaft and taking the cylinder head off, we’re not going to strip the engine down any further. The rebuild will begin once funds permit.

Willh1983uk · « **Reply #42 on:** March 06, 2018, 01:22:25 PM »

More pics.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #43 on:** March 06, 2018, 01:24:45 PM »

What size are those pistons?

No o-rings in those 2 outside blank spots where the oil orifice jets are lined up?

Cam looks big.

Willh1983uk · « **Reply #44 on:** March 06, 2018, 01:26:12 PM »

I’ll measure them tomorrow evening.

Willh1983uk · « **Reply #45 on:** March 07, 2018, 12:35:16 PM »

Just an hour with the bike tonight, measured the pistons and as far as I can make out they are 63mm in diameter. I’ve also petrol tested the valve seats and cleaned the excess head gasket off of the top of the cylinders. Regarding the ‘o’ seals, do you mean the blank spots circled in the photo? All in all a steady night.

Jerry Rxman Griffin aka MuthaF'er · « **Reply #46 on:** March 07, 2018, 01:17:01 PM »

Yes, that is what I was referring to. The parts manual shows 4 of them (5.8 x 1.9). I only saw 2 on your head and wasn't sure if it in fact had all 4 when you took it apart.

The pistons do look bigger but 63mm is an odd size for a 750. 64mm/812 is common as is 65mm/836.

Willh1983uk · « **Reply #47 on:** March 07, 2018, 01:22:07 PM »

Quote from: Jerry Rxman Griffin aka MuthaF'er on March 07, 2018, 01:17:01 PM

Yes, that is what I was referring to. The parts manual shows 4 of them (5.8 x 1.9). I only saw 2 on your head and wasn't sure if it in fact had all 4 when you took it apart.

The pistons do look bigger but 63mm is an odd size for a 750. 64mm/812 is common as is 65mm/836.

I measured them while they were in place so there is more than likely an error in my measurement. I’ll have to look under the cam carriers to see if there are any ‘o’ seals stuck to it. The previous owner did have a cam/associated can gear overhaul.

Willh1983uk · « **Reply #48 on:** March 29, 2020, 04:56:12 AM »

After a substantial amount of time spent on the bike I've gotten back round to updating my project. Along with a rebuilt engine and powder coated wheels and frame what started out as a small project to keep busy has turned into a labour of love and is now taking up all of my spare cash.

SOHC4 Cafe Racer Fan · « **Reply #49 on:** March 29, 2020, 11:23:27 AM »

That looks like an original Superbrace fork brace on the front end. Those are hard to come by.

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Author Topic: My first protect, Honda CB750G revival. (Read 7559 times)