Author Topic: 76 CB550 Cafe build (Read 88989 times)

tshrey · « **Reply #700 on:** September 20, 2022, 07:48:26 PM »

Got the box done in rough form, no time for testing. Final air cleaner cover will be a wide opening like a hood scoop pointing at the ground, but I want to see if I have any other issues first. I was originally happy that none of my sides are parallel to prevent any resonances but I realized the top and bottom are parallel. We'll see if it matters.

tshrey · « **Reply #701 on:** September 21, 2022, 04:09:12 PM »

Airbox installed on the bike with the vent line from the valve cover running into it. Definitely muffles the intake racket, but there is now a 1.5 pound airbox hanging off of carbs hanging off intake manifolds hanging off the stock manifold rubbers. Didn't want to ride it like that, will make up a support bar to let it hang from above.

Also installed the second rotor and caliper and joined them using a brake line over the fender and a double banjo bolt. Kind of a PITA to bleed, that extra hoop, but I got it done.

Godffery · « **Reply #702 on:** September 21, 2022, 05:36:08 PM »

Nice work on the Airbox!

SOHC4 Cafe Racer Fan · « **Reply #703 on:** September 22, 2022, 08:39:41 AM »

That's a robust airbox solution. I wonder if it's something you could spec out in CAD and have 3-D printed to save weight.

tshrey · « **Reply #704 on:** September 22, 2022, 09:17:42 AM »

That was going to be my first effort, but I don't play with 3d software enough to make the venturi's. Easier just to go old school and make it.

But you are right, something out of a fuel stable plastic would save weight (would PETG work?) and I could make it less blocky. We have a metal 3d printer at work, think how sexy it would be out of titanium!

I think I would still want to support it above just because it gives the carbs support from both sides instead of cantilevering off the intake manifold rubbers.

grcamna2 · « **Reply #705 on:** September 22, 2022, 10:11:51 AM »

Quote from: tshrey on September 22, 2022, 09:17:42 AM

That was going to be my first effort, but I don't play with 3d software enough to make the venturi's. Easier just to go old school and make it.

But you are right, something out of a fuel stable plastic would save weight (would PETG work?) and I could make it less blocky. We have a metal 3d printer at work, think how sexy it would be out of titanium! I think I would still want to support it above just because it gives the carbs support from both sides instead of cantilevering off the intake manifold rubbers.

A top bracket on both sides will help support that and the carbs.

tshrey · « **Reply #706 on:** September 27, 2022, 12:10:11 PM »

Airbox powdercoated and a hanger installed. Still need to put the scoop over the filter, right now the rear tire kicks sand up into the filter, but I've been riding it like this. Actually flows more than the K&N's right on the carbs, needed to richen everything up a smidge. Didn't quiet up the intake racket as much as I had hoped but I think the scoop will aid in that.

Adding the second rotor and caliper on the front was a huge change though. This thing STOPS now.

tshrey · « **Reply #707 on:** September 27, 2022, 02:26:29 PM »

A new project bike kind of fell into my lap. Going to update the sale thread on the drivetrain and make it the whole bike.

tshrey · « **Reply #708 on:** October 07, 2022, 06:23:04 AM »

Murray has updated his intake manifolds for the VM34 kits - he has welded flanges right on to his splitter manifold so you don't need the stock intakes and rubbers, the carb kit now bolts right up to the head. Ordered the update, should make a lot more room everywhere. I'm also pretty positive I have a leak on the rubber for cylinder 3; I don't hear the idle change when I spray starting fluid around it but after a ride the bottom of the rubber is wet with fuel so this should take care of that issue.

tshrey · « **Reply #709 on:** October 10, 2022, 10:10:12 AM »

Ordered a banged up set of stock pegs off ebay. I think one of the reasons I'm having wrist issues is that while the cognito moto rearsets look cool, they put the peg behind my ass, so even though the reach to the bars isn't far for me I'm kind of cantilevered forward. Going to weld on a disc of 3/8" steel plate to the mounts and move the pegs/levers up to something close to a stock location. Have to make a new rear brake linkage but that is pretty simple to do.

RAFster122s · « **Reply #710 on:** October 10, 2022, 12:50:05 PM »

Carpal tunnel issues are really sensitive to pressure on the wrists. You can cause it to flare up with a forward lean riding position. While people may love the aesthetic of rear sets and low bars some of us cannot tolerate it due to health issues.

tshrey · « **Reply #711 on:** October 14, 2022, 11:58:33 AM »

Well f*ck me. I got the new version of Murray's intakes that bolt right to the engine, put them on in the jetting configuration that he shipped them out with almost two years ago and the bike is now awesome. I must have had a leak in the rubber insulators between his intake and the stock intakes that would come and go (or the oring wouldn't seal on one of the cylinders); sometimes the bike ran great, other times it was pot luck if I could leave a stop without stalling (or if would even idle when I came to a stop). I can't even tell you how many times I checked for leaks, it must have been that once a certain rpm is reached the vacuum level goes up enough to seal whatever hole I had. Really changes my outlook on this thing.

Still not terribly comfortable to ride. I got the stock pegs from ebay today and am working on a new mount point for the cognito moto pegs/levers using them. Then Hagon shocks set up for the weight of the bike, no matter what springs I use they are way to stiff since the bike is 130# lighter than stock and cannot carry a passenger. Also need to order new front springs from racetech for the GSXR forks, what is in there is also about 20% too stiff.

grcamna2 · « **Reply #712 on:** October 14, 2022, 12:54:38 PM »

Glad to hear you have the new Murray's manifolds that bolt directly yo the head ports

I know the rubber carb insulators leaking is a real pain on any bike.
How does it run for you ?

tshrey · « **Reply #713 on:** October 14, 2022, 01:05:53 PM »

Everything is great. From an engineering standpoint I wish he would flatten out the angle from the carb, at idle the center two cylinders get a lot more fuel and the exhaust is almost 100 degrees cooler. I get why he does it, it is just a little extreme. Part of it is also packaging, has to make the carbs fit between the frame, but with these new manifolds there is more room.

So much quicker than stock carbs (assuming the stockers are jetted properly).

tshrey · « **Reply #714 on:** October 19, 2022, 02:05:36 PM »

New peg mounts done. Same location as the stock pegs, just a little bit higher to allow for all the bolt and nut installation clearances. Kick start even works. Basically keeps all the load now off my wrists even with the clipons.

Ran it into work and 3d scanned it and then ran it through FEA and the most stress is where my welds are so we will see how good I am at welding

tshrey · « **Reply #715 on:** October 21, 2022, 11:31:15 AM »

So this is a no-go. Right side peg is too far away from the bike (although that must be pretty close to stock) for my liking and both sides are just too far forward. Also, kickstand winds up under the shift lever so you can't kick it out with your foot. I can say that it took all the load off my wrists though.

I'm going to make a hybrid of the cognito set that just puts the peg in the opening where the stock footpeg mount runs. Splits the difference in height and forward/backward and keeps them tucked in like the cognito set.

tshrey · « **Reply #716 on:** October 25, 2022, 09:17:08 AM »

Raw fabrication done, I'll make them prettier later. Location is perfect. Had to make new brake linkage and exhaust hanger but I'm getting pretty good with the stainless welding so that went quick. Going to be 70 and sunny today, looking forward to a nice ride.

In another development, I got a new toy delivered today

grcamna2 · « **Reply #717 on:** October 25, 2022, 09:54:34 AM »

Good work on that fabrication and Nice Lathe !
I'm concerned that your rear brake pedal sits so low.. it looks in an awkward position to apply any force to the pedal.

tshrey · « **Reply #718 on:** October 25, 2022, 09:57:51 AM »

That's all parallax from the photo. I already dialed everything in, shifter and brake pedal are right where they should be.

Edit: I did have the tip a little low, I turned the adjuster back two turns to bring it up. I do ride pretty 'toes down' though so I guess it could look funny. Other thing to remember is while not as far back as the Cognito mounts these pegs are still about 6 inches back from the stock location, so your foot is definitely pointed down more than stock.

tshrey · « **Reply #719 on:** October 29, 2022, 01:41:23 PM »

After the change to the new intakes that bolt directly to the head the bike is a different creature. But there are still occasionally weird behaviors and if there is a scab I pick at it. Went for a ride, pulled up and shut off the bike and then pulled the #4 spark plug. Perfect color. Started the bike up and it would barely run. Then I realized I left the plug wire disconnected. Plug it back in and everything back to normal. Repeating now for 1, 2 and 3. Same behavior for 1 (at idle the bike runs cylinder 2&3 very rich, so most of the work is done by 1&4). Pull 2 and it is noticeably rougher but will still run. Pull 3 and the same BUT the motogadget tach, which is getting its signal from the coil for 2&3 now reads a bouncing 3k rpm.

I can't think of anything that would explain the tach double counting when one of the plugs are disconnected. Thoughts?

Alan F. · « **Reply #720 on:** October 30, 2022, 11:25:27 AM »

Quote from: tshrey on October 25, 2022, 09:17:08 AM

In another development, I got a new toy delivered today

New Lathe Day! Wooooo!
Congrats, enjoy setting that up and exploring what it can do.

tshrey · « **Reply #721 on:** November 03, 2022, 01:21:29 PM »

Cleaned up the new mounts and powder coated them hot rod texture to match the cases. Very happy with the peg location now.

tshrey · « **Reply #722 on:** November 06, 2022, 08:37:29 AM »

Stupidly warm day for November, went for a nice ride. Is there a consensus on how long it takes these motors to break in? I'm at about 750 miles now and this thing just keeps feeling and sounding better and better. @Hondaman, @Godffery?

Also, I normally just run around with the petcock set to Reserve and make sure I fill up at 100 miles. Today I actually had it set to On and it stalled at a light before I set it to Reserve. Filled up five miles down the road and it only took 2.3 gallons? I would think I should clip a cm or so off the top of the inlet pipe, no?

Couple nice new snaps...

wolf550 · « **Reply #723 on:** November 06, 2022, 09:05:14 AM »

hey tshrey what did you do with your old set of rearset brackets?

tshrey · « **Reply #724 on:** November 06, 2022, 09:11:16 AM »

Going to sell them. I was thinking of making it a kit with a 550F kickstart lever since I flattened the hump off the kickstart side and that is the only way of getting a full kick.

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Author Topic: 76 CB550 Cafe build (Read 88989 times)