Honda "l'arancio dolce" CB 750 Resto-Mod Project

[2_DONE_THE_TON]

Re: Honda "l'arancio dolce" CB 750 Resto-Mod Project

More progress on the Honda.
Cleaned out the oil sump yesterday after letting it sit in diesel.Drained all the remaining old oil from the oil tank.
Slow but good progress.
The fine dust on the oil pump grid turned out to be rubber dust.
Cleaned the oil sump screws. This will go back on the bike today.

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[2_DONE_THE_TON]

GOOD PROGRESS ON THE CB! 8)

Invested some more time and now I have spark on all 4cylinders!

Cleaned the points,regapped one of them (it wasnt not closing properly) mounted new plug boots on 2 of 4 cylinders.
and boom! we have spark!

Here I have a question: Is it possible to remove the spark plug wires from the coils?They look like they are "hardwired" to the coils?I would like to replace them.

Also I cleaned the oil system with some fresh oil, drained and flushed the oil tank with oil.
Remounted the oil sump.

Hopefully I will be able to start her up soon!

 

[irk miller]

I have tried those particular ones, so I'm speculating, but I have done several others that came on Cb360's. The coils had a hole with a metal screw center in the bottom. The wires were pushed into the hole with epoxy from the factory. So, all I had to do was break up th epoxy, pull the wire out, push a new one in with epoxy. Pretty easy. It would be nice if yours are the same way, but I haven't tried with them.

 

[der_nanno]

Epoxied in. 50:50 chance at best to get them out without breaking the coils.

 

[2_DONE_THE_TON]

Re: Honda "l'arancio dolce" CB 750 Resto-Mod Project

Put in the work..
Popped in the carbs and boom the bike ran for a few strokes!
Carbs were losing gas over the brass pipes on 1 and 4 and no gas in them so I guess I swapped float chamber 1 and 4...or do you guys have another idea?
The floats and needles look like they are in good order (new needles).

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[irk miller]

Try polishing the seats of the float valves.

 

[pidjones]

Re: Honda "l'arancio dolce" CB 750 Resto-Mod Project

The needles can stick at first - try tapping the float bowl with the handle of a screwdriver. The brass overflow tubes also develop cracks along their length, can be soldered.

 

[2_DONE_THE_TON]

So just pulled one of the carb bowls. Looks like there are tiny holes in the brass pipes. Is this supposed to be down there?
These brass tubes are supposed to be without any holes till the top to work as an overflow aren't they?

I will fill the chambers with fuel and pump some air from the bottom to see if these holes are really holes or just caverns.

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[pidjones]

Re: Honda "l'arancio dolce" CB 750 Resto-Mod Project

Just pour rubbing alcohol (isopropyl) in them and see if it comes out the tube (with the drain closed, of course). They can be soldered with plumbing solder and a powerful (I use butane powered) iron and using acid flux. Clean well first.

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[2_DONE_THE_TON]

Try polishing the seats of the float valves.

Again success!

I did all what you guys said...Took the carbs off and polished the needle seat with some tooth paste and q tips.Then I checked on the cylinder 1-4 brass pipes and YES, number one has at least 5 holes in it.The needles were sticking to because I tried filling the bowl with gas and the drip was minimal.
I will solder these holes but for now I will leave them since after polishing the carb seems to hold up fine!

I litered the carb out, there seems to be a big difference in float height setting.Do you guys know the right float height setinng for the K7 models?Normally these are in 20MM range.
I cannot find anything about that in my manual.

Before I start the bike I would like to see that the oil is coming up into the head, how can I check on that?
Thought about removing one of the caps on the head, remove the spark plug caps and then turn the engine with the electric start to see if oil is going there.

Thanks in advance!

 

[teazer]

I would suggest checking the FUEL level. You could do that by replacing the drain screws with adapters and set teh fuel levels on all 4 at 3mm below the gasket surface.

 

[der_nanno]

Check the float height with one of the floats being set parallel to the gasket face ...and then set the others to the same height. This might not be the 100 percent setting, but it should be good enough to move on.

 

[Maritime]

To answer the oil question yes do exactly that. pull plugs to make it easier to turn over. pull a cover and turn over with the starter until you see oil flow in the head. Good idea to do that so you don't have the first start be dry.

 

[teazer]

Check the float height with one of the floats being set parallel to the gasket face. This might not be the 100 percent setting, but it should be good enough to move on.

"should be" sums that up. That's more or less how much of us do it, but you may be surprised how far off the actual fuel levels are. That's why it's better to set FUEL level on any older bike.

 

[2_DONE_THE_TON]

I will do the fuel level for sure thanks teazer!

I call that a success!
The bike runs even for now just with a screwdriver
Put the carbs back on and tried it.
The bike holds no idle runs only on choke and needs to get revved up so I guess I will need to check the small jet system in the carbs again....
The ignition gaps needs to be set too correctly.

Cylinder 2 and 3 still run the old spark plugs.
All spark plug boots are fresh.


https://youtu.be/xBiaWKEXH80

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[pidjones]

Re: Honda "l'arancio dolce" CB 750 Resto-Mod Project

The 750s take quite a while to warm up enough that they don't need the choke.

 

[der_nanno]

"should be" sums that up. That's more or less how much of us do it, but you may be surprised how far off the actual fuel levels are. That's why it's better to set FUEL level on any older bike.

Yeah, I got interrupted mid sentence. I corrected it above.

From my experience it is more important to set all to the same height than the exact value. Personally I like to set floats rather high to make sure, I don't run in any starvation issues. But this is really *JUST* a personal preference.

 

[2_DONE_THE_TON]

Re: Honda "l'arancio dolce" CB 750 Resto-Mod Project

I need to check too if the cam is lubed properly.
There is definitely coming oil to the head but I will check more next time I start the bike up again.
Still stoked that the bike ran on the 2 bad old fouled plugs...
When I know that the engine is sound (which it really feels like at the moment, no clacking or bad sounds) the bike will be fully disassembled.
Frame will be cleaned from the police brackets that were welded on and the bike will be Black with the stock Honda decals.
Long way to go but I feel motivated now!

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[2_DONE_THE_TON]

So good news guys!

The CB runs on its own terms, starts on the first push of the button and I tried with a q tip and the head gets oil to the camshaft!
The only thing that bothers me is that the cam chain makes a bit of noise...So I will try to do the cam chain tensioning drill...Found this video on Youtube.
What I dont get is that the guy on the video refers to the most right cylinder as cylinder 1?maybe it is because i´m left handed but this seems illogical...
help is appreciated!

https://www.youtube.com/watch?v=8841eO5tvro

 

[irk miller]

So good news guys!

The CB runs on its own terms, starts on the first push of the button and I tried with a q tip and the head gets oil to the camshaft!
The only thing that bothers me is that the cam chain makes a bit of noise...So I will try to do the cam chain tensioning drill...Found this video on Youtube.
What I dont get is that the guy on the video refers to the most right cylinder as cylinder 1?maybe it is because i´m left handed but this seems illogical...
help is appreciated!

https://www.youtube.com/watch?v=8841eO5tvro

Normally, we number the cylinders left to right as sitting on the bike. The video shows he has the exhaust tappet cover open, which is all the way left as you sit, but in the video it's all the way right, since he's facing the bike on the exhaust side. That's definitely #1.


The way the cam is set up on these, the 1/4 and 2/3 are at TDC at the same time, but intake on 1/3 and 2/4 are open at the same time and exhaust on 1/2 and 3/4 are open at the same time. This is why Honda did 4-into-2 and 4-into-1 exhausts with 1/2 and 3/4 matched.