Author Topic: Project Frequentus Interruptus (Read 5247 times)

Flying Tattooed Monkeys · « **on:** August 29, 2009, 01:22:28 PM »

This is the start of what will be a half-arsed, randomly updated (mis-!)adventure into the -for me!- unknown!

Picked up a complete but neglected '78 CB550K recently.
It's rough, rusty, and about as pretty as my reflection at 4a.m. on a Saturday morning.

No-one needs to see the in-progress stripdown photos, it should be pretty familiar to you all.

BUT, in the process, i've come across a couple of things that i'd like some wise opinions on.

Cue you guys

When i picked it up, it had spark, the starter was turning over, but it wouldn't fire. Turning the fuel tap on sent fuel spilling out of the overflow tube, like promises from a politicians mouth.
No problems, i thought, strip down the carbs, de-glaze, clean, rebuild and we're good to go.

Not that easy.
Everything moves freely, and aside from the lovely dusting of crystalized 95-octane, not to dirty inside.

As you can see, there's a crack at the base here in the fuel bowl. It's there in each carb, some worse than others.

Looking at these screws shows how Harry Ham-Fist punished the screws into place. I'm figuring these cracks are where my overflowing fuel problem originates.
Question - what do i do here? New bowls?

Flying Tattooed Monkeys · « **Reply #1 on:** August 29, 2009, 01:31:26 PM »

Question 2.

What's the meani...

Oops, wrong forum.

Again.

Let's get a bit Sesame Street here....
One of these things is not like the other ones.....

Is carb no.2 supposed to be different to the other 3?
I've got a crappy Clymer manual that seems to have pics from a pre-war scooter rather than this model CB!

Next question...

These are the only oil leaks on the whole motor. From the looks of things here, gaskets are the minimum....
Does the position of these leaks suggest any other nasties that might be lurking inside?

Flying Tattooed Monkeys · « **Reply #2 on:** August 29, 2009, 01:54:22 PM »

Now to give away the punch line before the joke has even started.....

Next question is one of æsthetics.

All placement of items in these pics has been guided by the steady hand of Tuborg! Nothing is final, just in mock up stage to get an idea of flow, lines etc

Stock tank and the start of what will become the new tail unit

OR this alloy number, which is hotter than doing both your girlfriends flatmates.

At the same time!

Yes, the jam-can will be a part of the finished bike!

Toyed with having the tail at this angle so i can get taillight/indicators underneath, but it's not really winning me over

No matter which option i choose, the more i look, the more i'm set on having the bottom of the tail piece horizontal. It flows well with the bottom of the tank, and also the sloping frame tube.
I'll eventually build a fibreglass seat base that will incorporate - most! - of this tail piece. If you look at the tail pice in the 'head-on' pics you'll see i have taped it. I think it needs sliming down somewhat.

What do YOU guys think?

MJL · « **Reply #3 on:** August 29, 2009, 06:16:50 PM »

If I am seeing and thinking correct, then yes, the number 2 carb is supposed to be like that. The other three are synced to that one.

That alloy tank is a hot little number, but leaves little room to park your ass unless you move the tail back (which I am sure you would)

scunny · « **Reply #4 on:** August 29, 2009, 06:29:57 PM »

looks like we have the same tank

Hush · « **Reply #5 on:** August 29, 2009, 07:50:16 PM »

Yes mate but he also has a kickstarter.

moham · « **Reply #6 on:** August 29, 2009, 08:45:51 PM »

I've "repaired" a cracked overflow tube with a sparse amount of JB Weld. Is still holding strong at 1000 miles, but I should probably check it soon to see if it has softened at all. I know others have used the same fix as it is not uncommon for these brass tubes to crack. If you don't like the HB Weld jimmy, then you would probably be able to score a set of carbs from eBay for not too much dough but then looking at another cleaning/rebuild with no guaranty of condition...

MJL · « **Reply #7 on:** August 29, 2009, 11:11:29 PM »

Haven't people used a bit of heat shrink tube over those tubes?

Flying Tattooed Monkeys · « **Reply #8 on:** August 30, 2009, 03:01:36 AM »

Yeah, the alloy tank is pretty long and robs a lot of seat space. I'm 6'7" so the tail is going to go back anyway, whichever tank i use.

As for the crack in the fuel bowl, it looks to be the cast section around where the tube sits, rather than the tube itself.
Upon closer inspection i found the ends of the each of the screws actually protruding into this area. No doubt the cause of the cracks in the first place.

I mean, when your tightening a screw, tighter has to be better, yeah?

Flying Tattooed Monkeys · « **Reply #9 on:** October 14, 2009, 01:28:16 PM »

Motor and frame are now seperate entities.....

More struggle than i realised, but very satisfying!

Flying Tattooed Monkeys · « **Reply #10 on:** December 15, 2009, 11:53:11 PM »

Ok, been a while, but collecting parts has taken time! Should be some progress now during the Xmas break.....

I have picked up a set of 750 pistons that will be getting a shave and haircut, a la The Gentlemen's Express. Also got hold of a 650 cam, some rearsets and some other bits and pieces.

Is there anything stopping me from adding a 650 crank to the piston-cam combo i've outlined?

sangyo soichiro · « **Reply #11 on:** December 16, 2009, 08:27:18 AM »

I like the name of your project.

yellowbirdrs · « **Reply #12 on:** December 16, 2009, 10:37:50 AM »

Nice!
What kind of tail is that?
It is custom made or you buy it some were?

Flying Tattooed Monkeys · « **Reply #13 on:** December 16, 2009, 11:22:49 PM »

Yellowbirdrs, it's a tail-piece from a late model Triumph. If you look in the last photo in post no.2, (head-on shot with the alloy tank) you can see it's a couple of inches too wide on my bike. Over the Xmas break i'm going to try and make a slimmed down fibreglass piece based off it.

Flying Tattooed Monkeys · « **Reply #14 on:** December 31, 2010, 11:45:01 PM »

WOW!
More than a year since i posted anything on this..... $:-\$

Happy New Year!

Well, there has been very slow and intermittent progress on the bike. Haven't had a lot to show, but i'm getting there!

Found another option for the tank. I liked the way it followed the lines of the neck at the front...

....but it wasn't cutting it for me at the back.

Decided to stick with the stock tank - the mounts are all in place, and it sits well on the frame = less modification!
Some knee pockets and some other trickery are planned. Photos as i get to that stage.

I don't like the rear of these frames - the pressed metal section just looks arse to me! So, 1,2,3 Sawzall!

Well, grinder and cut-off wheel actually!

What to do now for a new tail section?

Flying Tattooed Monkeys · « **Reply #15 on:** December 31, 2010, 11:54:29 PM »

Well, i have to say the Honda engineers were incredibly considerate! Who knew they would have enough forsight 30+ years ago to help out budget minded hacks like me? See, they built my new tail piece into the bike!

In keeping with the general lighter=faster cafe theme, some liposuction was in order....

Offered up to the frame, you can see things didn't quite match up

The green tape marks some of the relief cuts necessary to get things to flow better.

I ended up making a few more cuts.
Several sessions of weld, grind, repeat and voila, a new tail! I also smoothed out the pressed seam on top of the rail, above the shock mounts.

Flying Tattooed Monkeys · « **Reply #16 on:** January 01, 2011, 12:07:19 AM »

One of my aims here is to freshen up some skills i haven't used for a while (painting, fabricating) as well as develop some new (welding - teaching myself underway!, engine building).
Another aim is to build as cheap as possible, hence reusing or modifying a lot of the factory items. Hence the center-stand/tail section in the last post!

Another item i chose to re-use were the headlight mounts. To make enough space for the clip-ons, i trimmed them down equal amounts top and bottom. Here is one modded, one stock. I have some rubber mouldings ( from a plumbing bracket of all things!) for the cut edges that will make it look a little neater after final assembly.

I still haven't mounted the headlight bucket in it's new position, but i think the lower, tighter positioning should look good. Mocked up with clip-ons on place.

The green tape on the tank is me testing ideas for knee pockets...

Flying Tattooed Monkeys · « **Reply #17 on:** January 01, 2011, 12:20:55 AM »

Tank and tail piece mocked up on the frame. I'm liking the flow here more and more. I'll cut the leading edge of the tail piece back, most likely in line with the rear angled frame rail.

Notice anything missing in that last shot? I cut off the passenger peg-mount loop and cleaned up some of the unnecessary brackets from the rear of the frame. Which leads perfecltly into the next stage of the project!

New rear-set mounts. I loaned the idea from some of the other projects on this site, most notably Fun Jimmy. 9-way adjustment, with holes for 2 mounts on each bracket, means 18 holes per side, 36 in total. Pilot holes, drilled to size, then tapped. I turned each hole by hand, with the tap chucked up in the drill press as a means of keeping the threads straight in the holes. Notes to self are always handy, you never know how long it might be before next time you get to work on things!

Mounts tacked in place.

Flying Tattooed Monkeys · « **Reply #18 on:** January 01, 2011, 12:35:54 AM »

The mounts are almost finished, got a little more welding to do. I'm working on the design for the rear-sets. Not a lot to show there, lots of doodling on paper!
Next step, since the weather is so, ahhm, interesting!, is to pull down this lump.

Stubborn bloody screws on the cam-cover almost did my head in! Heat, impact driver, heat, impact driver... I broke 3 of the screws, but managed to get the cover off. The head is next!

I bought a used 650 cam a while back. I can't see a whole lot of difference between the 550 cam ( on the left) and the 650.

The sprockets are different - 550 is slimmer, and has a different shaped cutout in the center. They both have R10 stamped in them (towards the left end, if i remember correctly). The 650 has a raised J under the R10, and a raised R on the back (180 degrees from the J). The 550 has a raised J in the same place, but a 5 instead of the R. The lobes have different wear patterns on them, but i gather thats from badly adjusted rockers - the 550 cam from my motor has much more even wear than the 650. Any gurus care to chime in here, is this actually a 650 cam? any other differences i should be looking for?

fastbroshi · « **Reply #19 on:** January 01, 2011, 10:19:50 AM »

Good call on reusing the center stand! Definitely thinking outside the box there MonkeyFlyingOuttaYerButt! I'll be watching what you do with your rearsets, namely the brake side as I see you cut off the tube that the splined shaft goes in. Not that I did that...

cwchan · « **Reply #20 on:** January 01, 2011, 12:29:36 PM »

Quote from: Flying Tattooed Monkeys on August 29, 2009, 01:54:22 PM

I'll buy that old tank off you if you're not going to use it

Anti-Johnny · « **Reply #21 on:** January 01, 2011, 09:53:33 PM »

I like what youre doing! always cool to see someone going at it on a budget.

Flying Tattooed Monkeys · « **Reply #22 on:** January 03, 2011, 11:49:49 AM »

Sorry cwchan, that tank's going on another cafe project!

fastbroshi, i debated with myself a LOT before i cut the brake tube/pivot/thing off. But then decided to throw myself into the unknown.... Most likely end up using some kind of cable for the rear brake, eliminate all the stress of trying to get the brake rod to work properly.

Flying Tattooed Monkeys · « **Reply #23 on:** January 03, 2011, 12:01:45 PM »

The internals on this motor are remarkably clean!
Looks good all over.

Bit of carbon build up on the exhaust side of the chambers, but no scoring, damage or any problems so far.

So now i'm down to splitting the cases. I've removed all the bolts i can find and used a bit of gentle loving from the rubber-coated persuader, but the cases don't want to part ways.

I HAVE NOT removed the generator wheel or the oil pump - could these two be hindring the cases in separating?

Flying Tattooed Monkeys · « **Reply #24 on:** March 02, 2011, 11:40:44 AM »

Alright, finally got the cases apart!

According to my wonderful Haynes manual, in order to remove my primary shaft from the lower case i need a....Primary Shaft Puller!!
Anyone got any suggestions on where i can get my hands on one of these mythical tools??

cheers
Bret

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Author Topic: Project Frequentus Interruptus (Read 5247 times)