Topic: CB750 K2 restomod to "originalish" condition // Forkbrace added ! ! !

[Viktor.J]

Well this weekend I went home and could spend some time with the bike.
I didn't to that much.
 But first I put the (to me) new seat on and it looks great !
The "original" seat hade a big "ramp" in front so i could only sit next after the tank. But now I can sit where it's comfortable and it's much nicer

Here's the new seat.




I Also picked up the calipers and disc that a friend glass blastered for me, they look great and as earlier mentioned im going to paint the disc-center black and the caliper and caliper arms aliminium-colored.
A question, Im going to use primer right, BUT should I also put on clearcoat ? Ive never done "seriously" rattlecan paint jobs beafore.
Here's the brake parts !


Second question, Im going to run my steelbraded lines straight down to the calipers. Any problems ? Anything I should think of ? AND if anyone done the same please tell me the measurements, I've done my own but it's allways good to be on the safe side:D

I've also tried to start the bike. Maybe some of you know the "engine status" after my latest wash. Anyway. The electrics seems fine, I got a nice constantly spark. But she wont start, i pulled the plugs out and they looks like SH*T. Honestly I dont really know what I should read from them more then she gets to much gas right ? Any input ?

The spark looks good right ?
Gnista !

Number four (to the farest right) plug. Dry and black but a little bit wet on the threads.



Number one (farest to the left), wet and black.

[Stev-o]

Yes, primer should be used on bare metal but clear coat not necessary.

Plugs could be fouled, bike appears to be running very rich.  What jets do you have?


PS. Seat looks great, that is the one you picked up in NY, right?

[Vinhead1957]

Those plugs look like the bike was run with the choke on! Very rich but not a long time.  That condition would foul plugs and even if they weren't very old they don't fire and fail.   Solution is new plugs new fuel! Turn the bike over with a plug not installed but touching the head and confirm a good blue (strong) spark.

[Viktor.J]

Yes, primer should be used on bare metal but clear coat not necessary.

Plugs could be fouled, bike appears to be running very rich.  What jets do you have?


PS. Seat looks great, that is the one you picked up in NY, right?

Nice, Actually im so glad tight now. I found a ebay store in germany that sells alot of VHT products so

Im planing on a
Primer - http://www.vhtpaint.com/products/flameproof/
Color, disc - gloss black  http://www.vhtpaint.com/products/caliperpaint/
color, caliper and caliper arms - Cast aluminium
clearcoat - http://www.vhtpaint.com/products/caliperpaint/ (not sure if this is needed), but I'm probably safe then sorry.

I cant go wrong with that arsenal right ?

YEah the plugs are done. But I cant wrap my head around how they became like that after a wash Dont know about the jets, bike ran good until wash, so didn'r really care. and it was the end of the season. As it looks like now, Ill have to celan the carbs as im lifting the engine out to change the covers !

Yes, that's the seat. It looks great ( for the money). Thanks steve !

Those plugs look like the bike was run with the choke on! Very rich but not a long time.  That condition would foul plugs and even if they weren't very old they don't fire and fail.   Solution is new plugs new fuel! Turn the bike over with a plug not installed but touching the head and confirm a good blue (strong) spark.

It wasnt. Actually it haven't been runed much. A drove like 60 km and it went fine, then I washed it and this happened. Cant really understand why. But actually when I started the engine at first it sounded very rich, then after a few seconds it went normal. then after second wash it fired up but ran like #$%*, and then died. Maybe it (some how) got to much gas and fouled the plugs....

Is it possible that after wash the ignition went bad and therefore couldn't fire/combust all the gas. and thenrefor it became rich and fouled the plugs ?

[Vinhead1957]

Sounds like you got the points wet and shorted out some of the spark.   Check under the cover for moisture.   If so, a hair dryer works well

[CROMOLY]

Hi Viktor,
This plug looks like oil fouling to me.... I shure hope not for you..
Oily deposit will lead to misfire and week spark ,could be from oil leakage past piston ring or valve guides...
But would have no link with cleaning your bike
Anyways, let us know what you find



Cromoly.

[CROMOLY]

And also great work on finding a newish seat, looks good.still looking for one too, nothing under $350 canadian dollars
I rather spend money on other things for now

Cromoly.

[iron_worker]

This bike reminds me so much of how much bike looked. It also had a solid red tank just like that. Even the faded engine looks like mine did. ha

IW

[Viktor.J]

Hi Viktor,
This plug looks like oil fouling to me.... I shure hope not for you..
Oily deposit will lead to misfire and week spark ,could be from oil leakage past piston ring or valve guides...
But would have no link with cleaning your bike
Anyways, let us know what you find

Cromoly.

Yeah, problem is that first the ignition troubled, now the plugs are fouled it's hard to know which one came first, the hen or the egg
And as you say, the fouled plugs doesn't have any link to the washing, but maybe the washing messed up the ignition and then the plugs Thanks about the comments the seat was good but the seat and the 4 engine covers cost me 250 $ US...

Sounds like you got the points wet and shorted out some of the spark.   Check under the cover for moisture.   If so, a hair dryer works well

The points ( well I don't have any point ignition) went probably wet, either that or the kill switch. but can poor,no ignition cause fouling ? Either way the connections should be dry now, its been siting without pointcover in 15 degrees celsius for about 3 months
But there is spark, as you kan see in the video. I will try new points and hopefullt she starts up !

This bike reminds me so much of how much bike looked. It also had a solid red tank just like that. Even the faded engine looks like mine did. ha

IW

Ha im glad to hear that Iron_worker ! At first I thought of repainting the tank, but after I get the engine covers, front end and tank emblems sorted out I think it will look quite nice
Faded engine is soon gone, as you can see on previous pages (4) Im on my way to polishing up a new set of engine covers !

[Viktor.J]

Im waiting on my caliper paint and there's not really much I can do right now, and not from here.
But today I visited one of worlds (he as to be) most impressive private sandcast/honda collector. This guy hade 9 !!! top super duper mega restored Sandcast's. Not a single bolt, or washer was wrong. He had a mental knowledge of what the difference was between not only various models but in same model but different Chassie/engine numbers. Did you for example know that there's 3 different "spedo drives gears cases" within the K0 model ?
Besides the 9 Sandcast he had a Original real CR750, that bike was so sick ! We don't talk a replica, we talk a real CR750 !
And besides this he had like a 125cc , 350 scrambler, K2 with rare paint, a K1, some monkey bikes and a new object, the first CB750 shipped to sweden out of two that year besides that also a like 5x5 m small "warehouse" with a lot of NOS parts

I didn't dare to ask if I could take some pictures..

He gave me some gaskets to when Im changing my engine cases. He buys kits and doesn't want any gaskets that's not ORIGINAL Sandcast's gaskets. Even not new reproductions since.....they have the wrong color

Amazing, simply amazing !

Any way, here's the gaskets.. nothing funnier

[Stev-o]

Sounds cool. How did you meet the guy?

[Viktor.J]

Sounds cool. How did you meet the guy?

Im a member in " Classic honda club Sweden". Which is a members club for Honda's older then 30 years. And I'm a "contact guy" in my town, so some of the guys in the region got together to plan some trips and rides for the summer. the "contact guy" for this region is the man who had the bikes. So he called me and asked me if I wanted to come, and when he told me about some of the bikes I couldn't say no

I found some reports in the clubs magazine, yes we have a every two-months-magazine provided by the club about the members, the bikes, some tricks n'n tips etc

The bike is the same as they Used in daytona 1970, Engine tuned and "build" by Pop Yoshimura, Mister Mac drove it 71-76´. Yoshi Kasaka bought the bike in 95, then my friend bought it a few years ago.

Sorry for the poor quality

Some smaller pictures of the CR750.

Not the owner here, its a classic racing guy named Adam popp


CR750 at starter a start up.

And here are some of the Sandcasts

[Stev-o]

Nice. Wish there was a Honda club like that around here.

[CROMOLY]

Nice. Wish there was a Honda club like that around here.

Me too!


Cromoly.

[Viktor.J]

Nice. Wish there was a Honda club like that around here.

Me too!


Cromoly.

Nice. Wish there was a Honda club like that around here.

Yeah, it's nice. unfortunately though it's not a big club and most member are 60+ so they dont ride as often as I wish for. But at least it's close

[Viktor.J]

I got my spray cans on the mail yesterday and today I started to put on the primer on the rotors and the "not active caliper"-side.
It didn't went that well. But hey as with many thing, this is the first time Im trying to spray paint somehow serious

For starter the place is to small. Since it's still like 0 Celsius here in south Sweden I can't spray outside. And I cant do it in my apartment. So I had to take what I have a storage !
It's really small and the only things that went bad today was due to the lack of space
It did run on a small part and on some "hard to get places" the color didnt really fill in on all 3 coats. Put this is the primer so hopefully it sill turn out OK anyway.

This is ho I did and please, any comment and tips on how to do this are welcome !

The parts are glass blastered.
Cleaned them with water and compressed air.
Then cleaned them with "tak-rag" (with gloves)
Then cleaned with a rag and "chemical clean gasoline" (It's for removing oil,grease etc) (with gloves)
I then masked everyting (with gloves)
Then carried everything down to my little little tight storage, which I've decorated for this special purpose !

To the left, Im standing in the aisle spraying in. dont tell the land lord !


Hung it upp and then once again cleaned with "chemical clean gasoline", let it dry and then layed the first coat.
first thin layer coat
10 minutes
second thin layer coat (hung up on the wall so the can stayed a fraction of a second hence the run)
20 minutes
3 normal layer.
Left it to dry.


Checked in a few hours after and the primer look good I guess, the parts wasn't flawless before. Since it's white there alot of shadows that makes you think "WHAT I missed a spot"


a run






But here comes some questions. What do I do now ? Do I remove the masking, cure it in the oven then put on the color layers ? Or do I leave it there curing until I know it's dry then ad the color and after that removing the paint and cure in the oven ?
The back of the can says "apply all coats within 1 hour, allowing 10 minutes between each coat. for additional coats after 1 hour, wait 7 days for paint to cure. " Do I really have to wait 7 days until I can ad the color layer ?

Also, I'm having trouble cleaning my calipers. They've corroded/oxidized a bit. The cylinder-and brake pads walls are OK I guess. But the caliper seal "track" are worst oxidized. And I don't seem to remove it. I've tried to stuff the track with steelwhool and then trying to "wear it down", with not satisfying result.
How have you guys done ?
Remember it looks worse then it feels ( thats what she ... )



Appreciate any sort of input, thanks guys !

[Vinhead1957]

I would sand out any imperfections in the primer and blow off the dust 320 grit or finer, then coat with color thin coats as directed. Let dry a couple hours then bake at 200 only cause that is the lowest toaster oven setting for 30 mins

[rotormotored]

Hi Viktor,
I am a new member to this forum. I am enjoying your thread very much. I have a '78 CB750K that has been in pieces for several years now and just now I'm getting prepared to start rebuilding it. I will make it into some kind of Cafe style Streetbike. I am learning allot from this post. Keep up the good work and documentaion of your journey.

Thanks, Ed

[Rookster]

I've tried to stuff the track with steelwhool and then trying to "wear it down", with not satisfying result.
How have you guys done ?

Use aluminum foil instead of steel wool.  Same concept, pack it in and  use it to scrape away the high spots.

Scott

[Viktor.J]

I would sand out any imperfections in the primer and blow off the dust 320 grit or finer, then coat with color thin coats as directed. Let dry a couple hours then bake at 200 only cause that is the lowest toaster oven setting for 30 mins

Thanks, think I will use some 1000 grit paper and then blow of the dust with some "preassured air on can" since i dont have any compressor at home and dont want to carry everything to school

Thanks for the input !

Hi Viktor,
I am a new member to this forum. I am enjoying your thread very much. I have a '78 CB750K that has been in pieces for several years now and just now I'm getting prepared to start rebuilding it. I will make it into some kind of Cafe style Streetbike. I am learning allot from this post. Keep up the good work and documentaion of your journey.

Thanks, Ed

Thank you Ed. Welcome to the forum ! Seems like you have quite a project of your own, haha. I think a cafe/street bike is the way to go if you lacking some of the original "key design features" and such. But my personal opinion is to keep them "stockish" IF possible. But im no stock guy myself, since mine are lack have some modification but as some of the guys says here "its my bike and I do wath I want with it" and that's true
Thank you for your kind words and keep checking in, I will paint the brake parts this week

I've tried to stuff the track with steelwhool and then trying to "wear it down", with not satisfying result.
How have you guys done ?

Use aluminum foil instead of steel wool.  Same concept, pack it in and  use it to scrape away the high spots.

Scott

Oh, that could be something. Gonna give that a try ! Actually I managed to fit a 400 grit wet sandpaper and I think i got the worst parts. But gonna give the alu. foil a go also.
Thanks scott !

[Viktor.J]

The last week I've been "trying" to paint my brake parts (as you know). Last week I finished to prime all the parts. Due to the lack of space I have to wait a few days between each "new" parts since i can only fit like 2 pieces at a time

Anyway, the last friday I painted my rotors/discs black. As planed. It went good I think !


I left them to dry for like 8 hours. Then baked them in the oven for around 200 F/ 100 C.


The "not 100% smooth surface is the structure of the material and I think it looks good. More "alive"


BUT since the primer need like 100C, 200C, and then 300C for curing I planed to, First 1 hour at 100C then cool of for 1 hour then 30 mins at 200 C. But after 15 minutes the "color" startet to show some wear, and i pulled it out. It doesn't looks that good when looking at it close. But at 15-30 cm it's hardly noticable.
The curing wear, bubbles and sag.



Later I will paint the "non active brake pads"

[Viktor.J]

Hey guys !

I've run into some problems.

1: I got some runs and sags on one of the pads. The lighting is to bad and in some angles it's hard to see the amount of spray/color and therefore runs. I will get a extra lamp for the next things.
But, I sanded down the runs and I'm going to paint it again.
Whats the best method to do now ? sand it down, dust of and paint ?im afraid that the surface have same small amount of grease or fat, but im afraid to use lite acetone. ?

2: The other parts turned out OK. There are some molding defects and defects from 40 years of use . But overall it looks good, the parts aren't that visual.
But the color isn't that hard. The rotors that I painted VHT gloss black are much harder in the paint then the VHT cast aluminium parts. I cured the aluminium colored parts in the oven at around 115 C for 60 min, but even now after 2 days in room temperature I can make a "mark" with my thumbnail.
Do I cure it again or what do I do  ?

Here's some pictures, see the small marks on the caliper arm (where the caliper mounts).










Thanks for any help guys !

[Viktor.J]

I painted the calipers today, the painting went better then before.


BUT 3 h after the painting when removing them to the little "warmer" apartment I accidentally "scraped" the bottom of the caliper against my braking disc with a bad result
I guess this goes under the same category as the caliper side with rag, Do i sand it down and paint over again ?
Buhu, I get so disappointed on my self and my lack of patience..

[iron_worker]

Sand it smooth, wipe down with acetone (it is meant to dry with no residue), make sure it is completely evaporated before painting and giver.

IW

[CROMOLY]

It is no wonder painters charge a hefty sum, it is not as easy as it seems.
But you are doing a heck of a good job
Keep it up.


Cromoly.