Topic: Café/brat CB500 K3 -77, can't hold my fingers from it

[AlBundy]

Have now finished the wiring diagram and also added a table with the wires. Is the cable sizes correct Calj?

Next is to send the frame and wheels for PC. Then change all engine gaskets with genuine ones from David Silver. Have also got another disc and caliper for dual disc conversion.

Anyone who has good experience with Hagons? Should I go for the 31012SS or 31012TTSS? I will just use the bike for street cruising, sometimes with wifey.  Maximum weight will be around 140kg/300lbs.  https://www.hagon-shocks.co.uk/catalog/config.aspx?TypeID=T

[AlBundy]

Hi people. Have bought an extra rotor disc and caliper for dual disc conversion. From what I have read a master cylinder with a 16mm piston gives the best ratio. I have bought a Nissin master cylinder including a clutch lever from a company that sells used motorcycle parts here in Sweden. Before I bought the master cylinder I asked the company if the piston size is 16mm and they told me that it was. Now when I got the master cylinder I can see that it has 1/2 and also a 3 text on it. The seller told that the master cylinder is from an 750 f2 sevenfifty 1998 and that bike has dual discs. Is it right that the 750 has 1/2 piston? And will this master cylinder work correct with my dual discs?

[AlBundy]

If its labeled "1/2" inch then thats 13mm, not 16mm. Personally, I think you'd prefer a 13-14mm MC to provide more "feel" in your brakes, even with dual discs. A 16mm would likely create a "wooden" feeling because there will be significant braking pressure created by minimal actuation of the lever; thus no modulation by the rider.

Add some stainless brake lines and give it a go. Remember, despite dual discs you are still dealing with single piston calipers, so thats a good portion of the "limits" of these brakes.

Ok. Will keep the MC then. Thanks!

[AlBundy]

Have started to tear down the engine to check if it's in good condition. Have never done something like this before so sorry if I ask stupid questions.

Should I be worried about the scratch in the bore? When I scratch it with my nail I can feel it a little bit.

The valves.  Are they bad, or should I take a better picture when I get them out to get an good answer? For me it looks like the exhaust valves are bad.

Rocker arms. In what condition are they?

Cam chain. It's stamped with DID. Is that genuine or has it been changed? Also the condition? There were just a little bit of slack when I checked it (not much at all).

Cam chain tensioner. Good or bad? My guess is that it's hard to tell because of the bad picture but here are so many pros so someone maybe can tell me. Will get it out tomorrow for a better picture though.

[AlBundy]

Sharing some of my progress. The engine is in the stage of cleaning. Will need to change the primary chain since I can see some scraping in the case. Also the cam chain will need to be changed with it's tensioners. New gaskets and piston rings.  The valves were ok. Have cleaned them with soda blasting which I did with pulverized lime.

In the background of the picture is my freshly powder coated frame along with a marauder 125cc and a gilera stalker 70cc.

[RAFster122s]

Rocker arms do not appear to be good from what I can see.  Care to post some closeups at a couple angles?
the chain would be replaced based on mileage or signs of wear or stretch. 
Did you plastigauge your bearings and crank?

David

[AlBundy]

Rocker arms do not appear to be good from what I can see.  Care to post some closeups at a couple angles?
the chain would be replaced based on mileage or signs of wear or stretch. 
Did you plastigauge your bearings and crank?

David

Will take some better pictures tomorrow. The cam chain shows some wear and also the primary chain has scraped the bottom of the crankcase. I plastigaged the cranks bearings and got about between 0.001 and 0.0015 in. If I have not missunderstood the manual theese numbers should be good. Right?

[AlBundy]

Two better pictures. The rocker arms are cleaned with diesel and 2000 grit paper.

[AlBundy]

For those who have a pita to remove old gasket material I suggest to use aircraft paint removal. Worked really good for me and took me less than 20 minutes without any hard pressure with the scraper.



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[RAFster122s]

Where did you hear that using 2000 grit sandpaper was a good idea for rocker arms pads?  New one for me...
Any of them that have pits or showed uneven wear before sanding should be replaced.  I would not use them in my motor.  The hardened face is not very thick and when you have uneven wear it will cause the same to occur on the cam.  Are your rocker shafts showing any play when you pull up or down trying to get them to move in the cover?  If so, you are having eccentric wear in the cover, not uncommon for 74-76 covers. The 77-78 covers were pinned so they would not rotate.
That's my $0.05
David

[AlBundy]

Where did you hear that using 2000 grit sandpaper was a good idea for rocker arms pads?  New one for me...
Any of them that have pits or showed uneven wear before sanding should be replaced.  I would not use them in my motor.  The hardened face is not very thick and when you have uneven wear it will cause the same to occur on the cam.  Are your rocker shafts showing any play when you pull up or down trying to get them to move in the cover?  If so, you are having eccentric wear in the cover, not uncommon for 74-76 covers. The 77-78 covers were pinned so they would not rotate.
That's my $0.05
David

I just wanted to clean them a little bit for a good picture. So it was not a good idea? :S Did not press hard at all with with the paper.

The shafts have only horizontal play, no vertical.


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[AlBundy]

2,000 grit won't hurt them. It may help polish them up a bit. The pitting in a few of the faces is cause for concern. Examine the corresponding cam lobe to determine if theres issues on the cam as well.

Will check the cam. Would u use theese rocker arms or would you change them?

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[AlBundy]

Have received my Hagons and can't wait to put em on the bike. Went with the black on black look, or black widow if you like it that way. Will be selling the Koni shocks, so if anyone is interested they can PM me. Better price for sohc4 members

This weekend I will be painting the motor, still waiting for the parts to arrive from the blaster guy though. Will go with Plasti Kote engine enamel spray can. Hopefully I will be able to get the motor together next weekend. It all depends if i get my parts in time from David Silver. More pics will come in the next days. Cheers!

[AlBundy]

A quick update. Have not painted the motor yet. The blaster guy is not finished with his job.. Starting to get frustrated since I want the bike bike to be completed to April/May when the season starts here in Sweden. Some new parts have arrived from David Silver and 4 into 1 though.

[AlBundy]

Things are happening the engine is painted and cured in the oven in 200 degres. Finally!!

Can't decide if I should polish the covers or paint them in gun metal grey color. Personally I think that polished looks better but it's very time consuming :/ Do you guys think it will look good with the covers in gun metal grey?

[AlBundy]

Somehow I managed to put in the cam chain guide blade the opposite way. Discovered it when I was about to put the cam on. Very rookie by me :/ almost started to cry when I realized my misstake. My question is, can I and should I re use the head gasket? I have only torqued down the head once and not re torqued it.

It was a very bad day yesterday. Made one more newbie misstake and broke the 6mm hex bolt  that holds the timing. Had to much torque on the wrench...Managed to drill it out though without any damage on the threads, happy for 5 minutes until I realized that the guide blade sat wrong.

[AlBundy]

You can re-use the head gasket without issue. In fact, releasing the head stud nuts, and stepping them back into their final torque is advantageous (as long as you don't shear any of them off...  ). Just raise the head enough to flip the blade, put it all back together again.

6mm bolts only need a maximum of 8# of torque. Thats a mild handshake's worth of tension. No need for a Ft/Lb wrench, just nip it up by hand.

Thanks Calj, you just saved me 70 bucks  . I ordered a new gasket since they (Lelles SWE) send it the same day if you order before 12am, but I managed to cancel the order just before they shipped it.

Might be a stupid question, but what do you mean with 8#?   

[AlBundy]

Sharing some pics of the build.

[AlBundy]

When I was dismantling the rear wheel hub I found that the flange was taped with electrical tape. Anyone who has an idea why this has been done??

[AlBundy]

When I was dismantling the rear wheel hub I found that the flange was taped with electrical tape. Anyone who has an idea why this has been done??

May well be the question of the century? Whats the red discoloration?

It's red electrical tape. I have removed the tape and the flange looks like it should. That's why I'm consued why it's been done...

Edit: The other discoloration is rust flow from the spraying with brake clenaer or wd40. It's also brake dust.

[SOHC4 Cafe Racer Fan]

When I was dismantling the rear wheel hub I found that the flange was taped with electrical tape. Anyone who has an idea why this has been done??

May well be the question of the century? Whats the red discoloration?

It's red electrical tape. I have removed the tape and the flange looks like it should. That's why I'm consued why it's been done...

Edit: The other discoloration is rust flow from the spraying with brake clenaer or wd40. It's also brake dust.

Maybe the PO thought it would go easier on the dampers.

[AlBundy]

Have been working the whole weekend with the bike and it is getting together slowly. Some pics and info what I've done.

New bushings for the swingarm and the shocks. Cleaned bolts and greased. New oil seals and oil for the front fork. Have put on the shocks and  the fork. Next is to polish the various engine covers and lace the wheels. Not so excited about the polishing, I must say.

[AlBundy]

So I'm about to do the wiring on the bike. Will have 6 days off from work, to work on the bike and the wife will be out and travelling so I'm going hardcore these days with my build. Before I start I want to double check if I can relocate the fuse? Like shown in number 2 diagram. Number 1 diagram is the old one. Also the REG/REC, I am getting a little bit unsure about if it is wired correctly? Calj, confirmation? 

I have changed some of the colors of the wires since the place I ordered them from didn't had all the colors I wanted in stock..

Have also manufactured a plate holder for the m-unit, REG/REC, and starter solenoid. It is made from a 8mm polyethylene board. It will be located behind the left side cover. Not finished with it yet, will be drilling more holes along the way when wiring.

[b.linden]

What program are you using to make the wiring diagram?

[AlBundy]

What program are you using to make the wiring diagram?

I am using TinyCad which a free software. To give the wires other colors thats not supported in TinyCad, I use Bluebeam Revu which I have on my laptop from work. The second one is not free but you can use it 30 days in trial mode.