Topic: CB750 K1 project

[mwvachon]

Cad, I realize this is of no help now, but I used a Veshra gasket kit on my K1. Almost 1K miles and no gasket issues thus far. As for the frame kit... You probably should take the engine out to do that - but then you don't really plan on removing it again after you fix the gasket issue, do you? As attractive as it would be to be able to remove the top end on my own K1's, I'm too chicken to cut the frame on either bike - even though I do have a weep at one of the pucks (between #1 & #2 cyl) under the cam holder on the gold K1. I'm approaching 50K miles on that bike and after seeing the benefits of new primary chain, bearings, rollers, and cam drive components on the red K1, I'm probably going to pull that motor to refresh the internals. Who knows, maybe I'll rebuild that rebuild as well while I'm at it...

[rtbmrgl]

I had a recommendation to use Gasgacinch on head and base gasket a long time ago, I also used Veshra gaskets.
There are several options on this subject, the only thing I familiar is what worked for me.

[Dunk]

I did use Gasgacinch on all gaskets and around oil passages on head and I believe base gasket too. It's good stuff. Maybe I shouldn't have used it on the rubber coated base gasket? Or maybe I didn't and should have? That gasket threw me for a loop and when I replace it I'll be going with a normal paper gasket coated with Gasgacinch as that's what I'm familiar with and have had very low failure rates with in the past.

I won't be doing a frame kit, I prefer to keep any modifications to restorations easily reversible or bolt on.

[Dunk]

Even with the leaks she sure looks nice...

[mwvachon]

Cad - I'll probably take some heat for saying this, but NOT doing a frame kit is probably a smart move. As these bikes age, the ones that are not chopped or irreversibly modified will realize a higher value than those that are. I am not saying some of the customs out there won't generate their own amount of interest - and man, some of the projects I've seen on this site are amazing! - but the real value will be with the most original models as time rolls on. If anyone doubts this, you need only look around at the current vintage 750 choppers that are out there. Back in the 70's this was the rage, much like today's cafe's. Some of those choppers are very well done, but there are a number of scary builds out there as well. Do you think someone would pay more for a chopper or straight vintage 70's CB750? I'm still digging the Polynesian Blue you stole out from under me [jk], but my latest Candy Red  restoration has really grown on me. That color just plain pops! Hope to still meet up this summer!

[rtbmrgl]

I did use Gasgacinch on all gaskets and around oil passages on head and I believe base gasket too. It's good stuff. Maybe I shouldn't have used it on the rubber coated base gasket? Or maybe I didn't and should have? That gasket threw me for a loop and when I replace it I'll be going with a normal paper gasket coated with Gasgacinch as that's what I'm familiar with and have had very low failure rates with in the past.

I won't be doing a frame kit, I prefer to keep any modifications to restorations easily reversible or bolt on.

Nerdos' has a clever and  interesting way to install the engine in the frame, seems to be without damaging the paint.

http://forums.sohc4.net/index.php?topic=130174.msg1551607#msg1551607

[SOHC4 Cafe Racer Fan]

Cad - I'll probably take some heat for saying this, but NOT doing a frame kit is probably a smart move. As these bikes age, the ones that are not chopped or irreversibly modified will realize a higher value than those that are. I am not saying some of the customs out there won't generate their own amount of interest - and man, some of the projects I've seen on this site are amazing! - but the real value will be with the most original models as time rolls on. If anyone doubts this, you need only look around at the current vintage 750 choppers that are out there. Back in the 70's this was the rage, much like today's cafe's. Some of those choppers are very well done, but there are a number of scary builds out there as well. Do you think someone would pay more for a chopper or straight vintage 70's CB750? I'm still digging the Polynesian Blue you stole out from under me [jk], but my latest Candy Red  restoration has really grown on me. That color just plain pops! Hope to still meet up this summer!

I suppose if a restoration is your goal, you should probably forego the frame kit.  You won't get any concourse points for it, since it didn't come that way off the assembly line.  That said, if a by the book restoration is not the goal, by all means install one!

[Terry in Australia]

Yeah, I can understand your reticence in chopping your frame mate, and as handy as it is if you're going to race a CB750 and want to do cam changes to suit particular racetracks, it's definitely not necessary, particularly on a stocker.

I don't use sealant on head or base gaskets, and my engines don't leak. Back in the 1980's I bought a book called "Great Bikes of the 70's" and in it there was an article on how to rebuild a CB750 engine.

What interested me was that the author recommended that you torque the head down to 19 ft lbs, rather than Honda's recommended 15. I did this, and adding my own twist, I left the engine overnight, then backed all the head studs off, then re-torqued them again.

What surprised me was that when I re-torqued them, they pulled the head down so much more than when I'd torqued it down the previous evening! I do this with every engine I build, and as per my previous boast, mine don't leak. No gasket goop, no special gaskets, (I buy the cheapest ones I can find on eBay) no snake oil, just a little bit of mechanical science. Cheers, Terry.      

[Dunk]

Friends, I've learned why we can't have nice things. Selfish liberals who drive recklessly without regard for anyone else on the road. A woman assaulted me with her vehicle last year so it's time to restore the K1, again.



A bunch of damage to the right side of the bike.



Fortunately no frame damage. Measured, stringlined, plumb bobbed, inspected for cracks or bends and all seems normal. So on to repairing the damage...

[Stev-o]

Wow...sorry to hear. Glad you're ok.

[Dunk]

Fork ears all bent up so pulled the front end. Checked tubes for straight, they are... But I was overly optimistic about a small rust pit in one tube last time around. Seal was leaking just a little. So, new K1 fork tubes from CycleX and through cleaned and reassembled with new seals. Fork oil was quite dirt with only 2068 miles on it. 10w oil last time around which felt a bit soft to me. Went with 15w oil this time and I'll see how it feels.





Reassembled and gave the lowers a quick hand polish.



Start putting things back together... New bars, tach rubber, tach crimp ring, tach backing plate, tach mounting ring, turn signal bits, ears and bucket, etc...



New turn signal and bracket on the back to replace the smashed and bent stuff. New rubber bits on them as well.



Put a washer on the outside of the grab handle on this side, didn't seem right without one but bolt in fiche was not long enough. Found that one of the bar clamp hold down bolts fits perfectly through the grab handle and turn signal bracketry with correct thick chrome washer on the outside.



Trying to figure out where cables route. Seems like clutch cable goes under the backbone from right to left, then around the stem and through the hole in the unicorn for a sharp turn to the lever. This puts the cable slightly in teh way of the bottom of the speedo. Not a big deal and I've seen many like this, but I don't like that it rubs on the painted metal gauge cover. Also not sure of throttle cables go through the unicorn hole or between the upper and lower trees, if so behind or in front of fork tube and headlight ear? I don't think I had all this just right originally.



Now I'm watching paint dry on the caliper and master cylinder. Master cylinder cap took some abuse from the road but cyl itself was good. Unfortunately brake fluid took some of the paint off so had to strip and repaint it.  Caliper had some very minor paint chips from stones or whatever on the road, couldn't put it back on as is. So just getting various other small parts ready to go back on now.

[Dunk]

Did a little more today.





Also got a Cibie ECE headlight since the original was damaged. Hoping for a significant improvement and that the charging system can keep up. If it performs well I'll put one on my K5 beater as well, though I'll have to go over that charging system as it barely keeps charged at 12.2x volts peak. The K1 does 14.x at RPM.

[Terry in Australia]

Looking good mate, obviously the damage wasn't too bad, but s shame just the same. Did you get any financial compensation from that woman driver? Your throttle cables go between the top and bottom triple in front of your right (kickstarter) side fork tube, then sweeps around the left (gearshift) side of the steering head. Cheers, Terry.

[SOHC4 Cafe Racer Fan]

Friends, I've learned why we can't have nice things. Selfish liberals who drive recklessly without regard for anyone else on the road. A woman assaulted me with her vehicle last year so it's time to restore the K1, again.

Did she assault you (inferring intent) or was she just someone not paying attention?

[oldhatt45]

Dunk,

While you're at it, Put in the Hondaman headlight relay solution!!!!!!
It will definitely Improve the lighting!!!!!!

Charlie
PS:  I have posted the wiring diagrams to do this.  If you want it, I'd b happy to post again here on your thread,

[Dunk]

I want to keep this thread about the bike. I have been compensated for the repairs with agreed value insurance. If I did not have agreed value insurance the property damage aspect would have been as much a nightmare as the medical. Medical compensation and treatment is an ongoing issue. I'm out a significant amount of money for that and have some permanent injuries. I'll elaborate once that aspect of this incident is complete.

I have got a pair of relays to wire up. I got the compact relays from http://easternbeaver.com/Main/Wiring_Kits/H4_Kits/h4_kits.html. I did not get the premade kit, just the relays and mini fuse holder. I prefer to custom make the wiring so it is exactly the right fit for the bike and discreetly hidden so it appears original. Just getting started on that tonight. Not sure if I need to run a separate ground as the ground in the repop harness seems a decent size. I'm leaning towards a dedicated ground since it's not much additional effort. What do you guys think?

I have an extra brown and black wire in the headlight bucket. I think I've got everything connected properly. I recall having one extra wire but not two? One I think is for the Japan model warning light in the unicorn tree. I'll test everything before installing the headlight.

I removed, cleaned, quick hand polished all the left side covers. I had a slight leak from the shift cover that was worse after going down and I noticed the alternator cover lightly weeping around one screw. Oil changed. These are old graphite core spark plug wires from a previous bike. I have black solid core wires I will install. They'll look closer to original and with the iridium resistor plugs I don't need the resistance of the graphite wires. I have new zero ohms caps I got a while back but they are red, or the wrong angle. I forget exactly but they're not like original so I'll go with the rubber boots. This bike has a Dyna S and 3 ohm coils. Hoping with the headlight upgrade charging doesn't become a problem. If it does I'll order Anders alternator upgrade if he's still offering them. I'm considering that anyway for the significant rotating mass savings.

So here it where I'm at. I'll probably do a bit more wiring tonight.

[chewbacca5000]

I don't visit this section of the site too much.  Did you get into another accident?  Were you ever able to use that k1 frame?

[Dunk]

Same incident from last year, just been slow getting to it since I've had another bike to bomb around on and life has been busy with recovery, legal issues, and work. Also agreed value insurance can be difficult to get on a total loss bike, I don't understand why but I suspect something with conspiring between government and insurance companies. Unfortunately I haven't done anything with the K1 frame you gave me, it's hanging from the ceiling next to a bent K1 frame with clean title. Switching the head is an option. In another thread Steve-O mentioned $200 easy peasy to get a title. If he got me a title I'd toss him $100 for the effort but he has not responded or elaborated in that thread. I've run the VIN and it's never been reported stolen or total loss. Clean VIN but useless at the moment because government.

Anyhow, I got the wiring done today. The harness came out quite nice, tucked in discreetly along the original and the fuse sits hidden but accessible between the starter solenoid and battery.









The Cibie/Philips light is extremely bright even without the bike running. Cleaned the carb bowls and fired it up for the first time since last September. Even with old gas it fired second kick, idles smooth, and throttle response is crisp. This engine is far more quick revving, smoother, and quieter than the K5 I've been bombing around on. I'm now motivated to button this thing up and ride.

To do list is short... Blast/paint right peg and replace rubber. Replace rear brake lever. Install headlight. Install side covers. Master is weeping a little brake fluid and bubbling up paint after I repainted it. I'll have to do something about that eventually. Not sure if there are shops that can anodize it like original for reasonable or if powdercoat may resist brake fluid better. Aside from that just go over all the nuts, bolts, and moving bits and verify everything it tight, secure, lubricated as necessary.

[Dunk]

Right peg is bent, need a new fixed part that mounts to frame. Not hugely bent, but enough to be noticeable and not feel quite right. Threw it on and buttoned everything up. Had a nice 50 mile ride and wow it feels nice to be back on this bike. Smooth, quiet, and plenty of power. Shifting was very notchy as compared to the K5 I've been riding, and once hot my dragging/neutral issues are back. I suspect this is from using different oil. I had these issues previously and it seems sensitive to oil to take the last little bit of drag out.

Also forgot how heavy the clutch is. Toward the end of the ride I was really feeling my carpel tunnel and not shifting unless I had to. I gotta get one of those gorilla grip squeezey muscle builder things. I did lube the cable and lever pivot before reassembly. I need to rotate the bars a little forward so I'm not bending my wrist up. I recall that made a huge difference in how long I could ride before wrist pain.

Still have a bunch of little things to finish up, but I couldn't wait any longer and went for a ride. We turned heads with a paid of CB750s...

[lash]

Same incident from last year, just been slow getting to it since I've had another bike to bomb around on and life has been busy with recovery, legal issues, and work. Also agreed value insurance can be difficult to get on a total loss bike, I don't understand why but I suspect something with conspiring between government and insurance companies. Unfortunately I haven't done anything with the K1 frame you gave me, it's hanging from the ceiling next to a bent K1 frame with clean title. Switching the head is an option. In another thread Steve-O mentioned $200 easy peasy to get a title. If he got me a title I'd toss him $100 for the effort but he has not responded or elaborated in that thread. I've run the VIN and it's never been reported stolen or total loss. Clean VIN but useless at the moment because government



Can you elaborate on switching the head to a new frame? I have a similar problem with a 1969 frame that a po "modified" and would like to fix.

[SOHC4 Cafe Racer Fan]

You'd be better off swapping to a titled frame or a frame that can be titled, then swapping steering headstocks.  You are swapping the VIN on a vehicle.  No bueno.

[lash]

The frame I want to fix is titled, the donor frame is not. I will take some pics next week and maybe start a thread on it for ideas..

[Terry in Australia]

The problem with chopping the steering head off a K0 frame to attach to a non-K0 frame is that there are subtle differences on a K0 frame that are not easy to replicate on later model CB750 frames, and whoever buys your K0 down the track will be less than happy if he finds out that his newly purchased K0 is a "Frankenbike".

When I was desperate to build my K0 I couldn't find a K0 frame here in Oz, so I bought a K0 neck from a member here to graft into a K1 frame (the closest match I could find to a K0 frame) but I couldn't bring myself to do it. Luckily I've recently bought a 1969 K0 frame and engine from another Aussie member, and while that frame has been messed with too, I'll graft the bits I need from one of my spare frames that won't affect the original frame's integrity, either physically, or morally. Cheers, Terry.

[lash]

I,m all for trying to fix the original frame ,just not sure how to do it. Need to graft in some pieces and cut some others. I will start a thread and see what the forum has to say.

[Terry in Australia]

I,m all for trying to fix the original frame ,just not sure how to do it. Need to graft in some pieces and cut some others. I will start a thread and see what the forum has to say.

Yep, start a thread and post pics of what you've got mate, there are plenty of K0 guys here who can help. Cheers, Terry.