Topic: 1977 CB750 K7 /// Rebuild 2.0, Project Anna

[mkoski]

Hey guys, I figured I would start a build log to keep track of where I'm at, what I am working on, to document my progress and to ask questions!

All images of this project (some of which I will embed) will be hosted here:

This is the first build I have ever attempted so I am learning everything on the fly. Fortunately I have received lots of help from this forum and I have a great motorcycle shop right by my house. I want to have the bike ready to go by April 1st, when summer riding in Alberta, Canada begins. I picked up my bike for quite cheap in a farm town and rode it back home ~150 km with it running on 3 cylinders so that wasnt very pretty and I was quite concerned that I wasted my money on the bike. After getting a spark in the 3rd cylinder and cleaning the carbs well she now runs great. I rode the bike for a month before beginning the tear-down process two weeks ago. I surprised myself with this project, as I have always wanted to restore a vehicle but never thought I would be working (or riding!) on a motorcycle as I used to always think of them as a death-wish until I rode one for the first time and realized how unbelievably fun they are!

Here is what she looked like right from the PO:




Those flames on the fender are just embarrassing...

I am attempting to convert this K7 into a cafe with style influences taken from some builds on this site and some professional builds and keep a reasonable budget of a few grand.

Here is a color scheme I am considering:


With lines that flow similarly to this:

[mkoski]

Here's the first update:

My goal right now is to get all the frame, forks and wheels all finished first so I have a rolling frame. From there I will build up the bike until its finished.

Frame is stripped right down, rear hoop (salvaged from a wrecked frame from some 60's bike) welded in.


Front and rear wheels are broken down into all of their respective parts (Not without issue...).

I broke off a bit while drilling the punch marks of the second rear bearing retainer...





Success!

One thing I have come into that is an issue is the K7 rear wheel is 17", which is a really poor size both for tires, spokes, ect. I was thinking about using a 18" rim for the rear. Is there any problem with that? If not, and someone has one for sale, I would be willing to purchase it! I am sandblasting and powder-coating the rims so its condition is not critical.

I am attempting to get all parts ready for powdercoating this week, as the lead time I was quoted was a month, in which I will work on the engine and order parts.

[SOHC4 Cafe Racer Fan]

Have you determined exactly what you are keeping/not keeping on the bike? If so, you should detab the frame; you've already cut off the rear fender mount/cross-member.  If you are not using the rear side covers, you can lop off those mounts, and the center stand mounts. A little bracing will help provide some added stiffness to the frame, too.

With respect to wheel size, there are more options for performance rubber with 17" wheels versus any other size.  That said, you will likely need custom ordered spokes.  The stock wheels are 19"/18" (front/rear).  You can improve your rubber choices (in comparison to stock) by going with 18" on the front and rears.

A "few grand" is ambitious for a bike as nice as the one you have pictured, especially IF you intend to lace new wheels on new rims.  Anything is possible if you do most of the work yourself. 

[mkoski]

Alright, I have decided (from your guys' advice) to stick with my 17" rear rim. Makes life easier for me as well, as I don't need to wait on a new rim to get the paint rolling! Ill just bite the bullet on the more expensive 17" rim spokes and the slightly uglier visual of a smaller tire.

For the frame I have indeed considered what will remain on the bike and detabbed the airbox mount points, removed the centerstand brackets, passenger peg mounts ect. I plan to use side covers unfortunately due to the effort and cost of relocating the oil tank, electronics and battery. Ill get better pictures tonight to see if anyone can spot anything I missed.

I'm doing all the work that is possible by myself, only using the shop for things that I really cant get at alone, so that should maximize my budget. The big items to purchase are clip-ons, spokes, rear-sets, exhaust, headlight with ears, tires, powder-coat, and potential to use electronic gauges. Im trying to keep it low budget but if there is something I want on the bike, I'll add it!

[mkoski]

Time to update this thread! Its been a while and I have been caught up in the usual things around holidays and what-not.

Since my last update I have sent and received all my parts back from powdercoating, most notable:

Frame:


Wheel assemblies, which I have laced and trued:



Forks, reassembled and built with new seals:


On the engine side of things I have painted her up after a very very thorough clean:

Dirty:


Clean:


Taped:


Primed:


Painted:


Bare fins:


Rotor has been drilled and painted (no pics):


Currently I am starting to put the frame together, triple tree with tapered bearings is in, swingarm is in, forks and rear dampers are in. Today I am getting my new tires (Battlax BT-45's) mounted and the wheels are complete. (Very excited about this milestone!) Next up is the deep cleaning of my carbs, which are a disaster in my living room...


And I am also waiting to receive my 3rd (!) set of hex-head engine bolts before the engine can go back into the frame. This is due to a mis-purchase of DOHC bolts and then a set of bolts that were useless that were shipped to me. What a PITA.

As you can see a lot of my methods are very red-green. I'll blame this all on being a new graduate, attempting to not destroy my bank account, working a in detached garage while the weather is mostly -20C with no heater and a minimal access to tools! I also have attempted to save some money by reusing stock parts like this triple tree:


But I think in the future I will upgrade to the billeted alum, much more attractive!

I'll attempt to update more frequently, as I am getting to the point where I can make use of your advice while I put the last of the major parts back together!

Throw your 2c in here, I like hearing what you guys have to say!

[mkoski]

Minor update, tires are mounted up onto the rims and balanced. They look great, very pleased with how they came out.



I'll be fitting the hubs with their respective accessories and taking a look at them on the bike. Rolling frame! Very happy to reach this point as well. I'll have a pic of this in a day or two.

Next major step is to install all the gold engine covers, bolt it together with new alloy hex-head bolts and drop it into the frame!

[SOHC4 Cafe Racer Fan]

Minor update, tires are mounted up onto the rims and balanced. They look great, very pleased with how they came out.



I'll be fitting the hubs with their respective accessories and taking a look at them on the bike. Rolling frame! Very happy to reach this point as well. I'll have a pic of this in a day or two.

Next major step is to install all the gold engine covers, bolt it together with new alloy hex-head bolts and drop it into the frame!

Good advice from Cal re dissimilar metals.  Are you a Dutchman fan?  (see crest to the right of your wheels)

[martin99]

Dutchman? That's the Three Lions crest of our ever-optimistic England team!

[mkoski]

Good catch with the allow bolts! I actually mis-typed, the bolts are stainless steel, I am just ordering them from Alloy-Boltz, thus the confusion!

Purely coincidental with the crest! I snapped the pic at my local motorcycle shop, just happened to make it into the shot!

[SOHC4 Cafe Racer Fan]

Dutchman? That's the Three Lions crest of our ever-optimistic England team!

Doh!!  How could I confuse the two!?!!  I guess I thought of the Cross of St. George as yours!

[welard]

Nice project and great work so far. Can't wait to see the color combination come together.

Can you kindly explain how you got the bare fins on your engine?

Cheers

[mkoski]

Nice project and great work so far. Can't wait to see the color combination come together.

Can you kindly explain how you got the bare fins on your engine?

Cheers

Sure, its actually a really simple process. I didn't really read up on it or anything, I just grabbed some coarse, medium and fine emery cloth (sandpaper would work fine!) and sanded the paint off the fin ends with a sanding block. With the way the fins are cast there are a few high/low spots so I did a bit of sanding without the block as well so that the exposed metal was consisiten. One thing I noticed is that I didn't get lines as clean as I hoped where the paint meets the bare metal (big jagged in spots). I will sharpen the lines a bit just by going over them again carefully with fine emery paper again.

[welard]

Thanks for that. Much appreciated.

I've signed up for updates on your project. Very impressive so far.

[mkoski]

I have a question for you guys about engine painting, hopefully someone can help.

So I have stripped, cleaned, painted my engine but I want to put a high-temp clearcoat over it to protect the work I have done. In retrospect, I should have used high-temp paint for the primer and the color, not just the final clear-coat... Too late now anyways. I do remember reading that I didnt need to worry about using special paint though from someone in a SOHC forum, thats why I didnt bother to get high-temp paint.

I was in the store yesterday and I was buying Dupli-Color Engine Enamel, clear and I googled it quick and got this article... http://forums.sohc4.net/index.php?topic=11044.0

Needless to say, I didnt buy that paint. I did go with this paint though... http://www.vhtpaint.com/products/flameproof/ in clear.

So! My question is: Will this be an acceptable clear coat to go over the paint on my engine? I know its not optimal but as long as it doesnt discolour and protects the engine a bit Ill be happy with it.

I just dont want to spray that on and ruin the work I have already done!

Thanks!

[SOHC4 Cafe Racer Fan]

I have a question for you guys about engine painting, hopefully someone can help.

So I have stripped, cleaned, painted my engine but I want to put a high-temp clearcoat over it to protect the work I have done. In retrospect, I should have used high-temp paint for the primer and the color, not just the final clear-coat... Too late now anyways. I do remember reading that I didnt need to worry about using special paint though from someone in a SOHC forum, thats why I didnt bother to get high-temp paint.

I was in the store yesterday and I was buying Dupli-Color Engine Enamel, clear and I googled it quick and got this article... http://forums.sohc4.net/index.php?topic=11044.0

Needless to say, I didnt buy that paint. I did go with this paint though... http://www.vhtpaint.com/products/flameproof/ in clear.

So! My question is: Will this be an acceptable clear coat to go over the paint on my engine? I know its not optimal but as long as it doesnt discolour and protects the engine a bit Ill be happy with it.

I just dont want to spray that on and ruin the work I have already done!

Thanks!

I think that the VHT and Duplicolor engine paints both work well with high temperatures, as long as they are used as directed (with fastidious prep) and preferably curing after.  I wonder if the non-engine paint underneath the clear is going to be problematic.  If that paint is not formulated to withstand high temperatures, it may start cooking off, discoloring and/or pealing underneath your appropriate clear coat. 

I don't want to burst your bubble, but keep an eye out.  I doubt, at this point, that you want to strip the paint and start over.

[mkoski]

I think you might be right. That's my concern! I am in a way hoping that putting a hightemp cover over everything might help the situation. I do know that many people paint their engines with regular sprays an dont have issues, so who knows?

Worst case scenario, I guess, is to repaint the engine again next winter, I suppose!

[SOHC4 Cafe Racer Fan]

I don't envy your decision.  You are faced with a significant possibility of having to pull the motor, strip it and repaint (if it starts failing) or undertaking extra work now for a "redo."  I guess it depends on the pace of your build and your temperance for uncertainty.  Pulling the motor is not the end of the world, but it sucks anyway.

[mkoski]

Two ideas:
1- auxiliary oil cooler to aid in lowering the oil temp.
2- Ride like a bat out of hell when you ride (air cooled and all of that) 

Option 2, of course. At the end of the day, I can live with a crappy looking engine for a summer. I was thinking of over-boring anyways...

We shall see how this goes after I log some miles!

[mkoski]

Engine is done. I'm spending a good amount of time looking at before it heats up, turns brown and sloughs off the paint... Looks fantastic from where it started (if I have to say so myself!).



I decided not to clear coat it with very high temp paint. If its going to cook off, that wont matter anyways so I figure better air cooling and easier removal in the future is worth it. Going in the frame tonight. Seems like I might be in good shape for the rest of this build now, not much to wait on any more!

[SOHC4 Cafe Racer Fan]

You did a nice job of sanding the edges of the cooling fins. 

[mkoski]

You did a nice job of sanding the edges of the cooling fins.

Thanks! I should mention my method, actually, as it might help some others out. I first went at it with a block and some medium grit emery cloth to remove most of the paint and then hand sanded with fine emery cloth. This brought it to a decent level but it still wasn't quite to my liking. I decided to try using my 4.5" grinder with a hard foam polishing wheel (which is too hard/fast to polish metal properly) and went along the fins with that. It came out gorgeous. The paint is sanded into really nice lines and the bare aluminum underneath is gleaming.

[Yoshimoto]

The engine looks great.  Keep up the good work.  Can't wait to see what it looks like when you are done.

[Trad]

The paint on your engine will be fine. In my late teens I would paint blocks and heads on my sketchy-ass motorcycles with regular paint and I never had an issue. As long as you did good prep you should be A-OK.

[mkoski]

Put the engine in the frame this weekend, starting to look like a motorcycle again. Carbs are apart and getting cleaned, gas tank is looking to be the next goal.



Trad, I hope you are right!

I initially researched the engine paint and I read a post from someone who only used regular paint and said it worked great (which is why I went forward with it), I just think now, in retrospect, it wouldn't have been any extra work to use higher temp paint and now have to worry. Either way, its done now.

[mkoski]

Post-weekend update:

Carbs:

Start:



Finish:



Very happy with these. It took me forever to clean these up and reassemble. Toughest part by far was trying to remember how the choke plate rods worked together with the spring! Not too many resources for these carbs!

I have a concern though, maybe someone can help me out:

My idle adjustment screw (pictured below) doesnt seem to have as much travel as it did before. The spring (which keeps tension on the screw, keeping it in place) is fully compressed just after the screw makes contact with the throttle rod linkage. I cant think of any reason why this is happening, as everything else seems to be lined up just like before and it doesnt seem possible that anything is different. If you have any ideas, please let me know!

Pic:



Unrelated to carbs, I have my last order of parts (except exhaust) on its way and tomorrow I will be powder coating my tank, top triple clamp, oil tank and batttery tray/electronics bracket.



After all these parts are in and the coating is done its pretty much just putting everything onto the bike, creating/fiberglassing the custom seat (I'm looking forward to this!), painting the seat and side covers, wiring her up and then getting her onto the road!