Author Topic: and so it begins, cb550k under the knife (Read 40148 times)

DMcD · « **Reply #100 on:** October 26, 2015, 03:22:27 PM »

Slow process on this rebuild!

Valves reground and new stem seals fitted. All four were sealing perfectly which was good.

DMcD · « **Reply #101 on:** October 28, 2015, 03:47:58 PM »

Very constructive evening, drilled and tapped a bolt hole in the barrells, fitted piston rings to chinese pistons, all gaps were checked in the barrells prior to fitting and were fine.

I then fitted the pistons with Honda circlips which were .91mm as opposed to the supplied chinese ones which were .89mm, and of a different design, sorry I forgot to take a pic of the difference.

And then fitted the barrells with new gaskets and O rings of course.

DMcD · « **Reply #102 on:** January 15, 2016, 10:47:18 AM »

Some progress, ordered a set of cr29s from dynoman, should get them at the start of next week. I know the problems, but I don't fancy struggling to make 26s fit. Hopefully they'll be ok with the 605 kit, open pipes, 650 cam and no filters. We don't get much dust in Ireland!

The first tank I made, was quite an achievement to get it fuel tight at the first attempt, but it was a bit rough so have started another one. I'll try to add pics later.

DMcD · « **Reply #103 on:** January 15, 2016, 02:45:11 PM »

1st attempt at a tank on the left, top of the cr750 inspired 2nd attempt on the right. Quite pleased with chin foam indentation. It is probably not as deep as it should be, but took me quite a while with a template and a rubber hammer.

SOHC4 Cafe Racer Fan · « **Reply #104 on:** January 15, 2016, 02:50:50 PM »

Nice evolution.

Lostboy Steve · « **Reply #105 on:** January 16, 2016, 05:09:07 AM »

Quote from: DMcD on August 08, 2015, 09:19:49 AM

Well that turned out better than expected, (head in dishwasher!)

I never thought about doing that.... You're not going to use it for dishes anymore i suppose?

DMcD · « **Reply #106 on:** January 16, 2016, 08:31:42 AM »

I did get into a little trouble

ran the dishwasher on an empty cycle afterwards which seemed to clean it.

SOHC4 Cafe Racer Fan · « **Reply #107 on:** January 16, 2016, 10:19:06 AM »

I'd run it a couple more times on VERY hot.

Godffery · « **Reply #108 on:** January 16, 2016, 02:27:19 PM »

Quote from: DMcD on January 15, 2016, 10:47:18 AM

Some progress, ordered a set of cr29s from dynoman, should get them at the start of next week. I know the problems, but I don't fancy struggling to make 26s fit. Hopefully they'll be ok with the 605 kit, open pipes, 650 cam and no filters. We don't get much dust in Ireland!

The first tank I made, was quite an achievement to get it fuel tight at the first attempt, but it was a bit rough so have started another one. I'll try to add pics later.

I supply a custom built CR26 kit made specifically for the CB550 application: (Mounts right on, no muck'n arround) http://www.vinmoto.org/gallery/v/VinMoto-Garage/album03/Godfferys-Garage-123/Parts+and+service/Keihin+CR26+Carburetor+Kit+for+1974-1978+Honda+CB550/

SOHC4 Cafe Racer Fan · « **Reply #109 on:** January 16, 2016, 09:55:44 PM »

Quote from: Godffery on January 16, 2016, 02:27:19 PM

Quote from: DMcD on January 15, 2016, 10:47:18 AM
Some progress, ordered a set of cr29s from dynoman, should get them at the start of next week. I know the problems, but I don't fancy struggling to make 26s fit. Hopefully they'll be ok with the 605 kit, open pipes, 650 cam and no filters. We don't get much dust in Ireland!

The first tank I made, was quite an achievement to get it fuel tight at the first attempt, but it was a bit rough so have started another one. I'll try to add pics later.

I supply a custom built CR26 kit made specifically for the CB550 application: (Mounts right on, no muck'n arround) http://www.vinmoto.org/gallery/v/VinMoto-Garage/album03/Godfferys-Garage-123/Parts+and+service/Keihin+CR26+Carburetor+Kit+for+1974-1978+Honda+CB550/

Godffrey,
How difficult is it to find a set of CR26s spaced for a 750? I have a 1979-80 CB650 head (same spacing as 750).

DMcD · « **Reply #110 on:** January 17, 2016, 02:09:17 PM »

Quote from: Godffery on January 16, 2016, 02:27:19 PM

Quote from: DMcD on January 15, 2016, 10:47:18 AM
Some progress, ordered a set of cr29s from dynoman, should get them at the start of next week. I know the problems, but I don't fancy struggling to make 26s fit. Hopefully they'll be ok with the 605 kit, open pipes, 650 cam and no filters. We don't get much dust in Ireland!

The first tank I made, was quite an achievement to get it fuel tight at the first attempt, but it was a bit rough so have started another one. I'll try to add pics later.

I supply a custom built CR26 kit made specifically for the CB550 application: (Mounts right on, no muck'n arround) http://www.vinmoto.org/gallery/v/VinMoto-Garage/album03/Godfferys-Garage-123/Parts+and+service/Keihin+CR26+Carburetor+Kit+for+1974-1978+Honda+CB550/

Hmm that looks nice, but I couldn't get my head around why 26s were so much more expensive than 29s? I am leaning towards track/fast road (isle of man) use, so hopefully the 29s will be bearable.

Godffery · « **Reply #111 on:** January 19, 2016, 10:13:45 AM »

It shouldn't be too much of an issue for me to space them for a 650 / 750 head, just depends on getting the right crossover tube parts installed.

The cost of my complete kit includes Everything needed for a clean easy bolt on and allow enough room for the high quality K&N RC-1820 Pods, (that are also included in the kit) The late model manifold's are shorter, spaced differently from the early model and are fitted with Vacuum tube adapters for tuning because the CR Carbs Do NOT have a place for them. The kit also includes custom machined spigot adapters (Only I make these and cost me $160 per set) also new OEM intake manifold rubber tubs and manifold to motor O-rings.
And if that were not enough, you will get them Pre-jetted, pre-synchronized, proper slide needles installed And I throw in Extra main and pilot jets for fine tuning.

In your particular case, having the 650 head. You will not need the intake manifolds or O-rings. Although I would still recommend new intake manifold rubber tubs if you haven't already bought a set.

SOHC4 Cafe Racer Fan · « **Reply #112 on:** January 19, 2016, 11:59:48 AM »

I am hoping this helps with the discussion.

I asked Buzz at Dynoman about CR26s spaced for a early (79-80) CB650 head (same as CB750 head). He said the parts to re-rack 26s for a early 650 head/750 head are not available, and IF SO would be too small for my 674cc kit (good for bottom end, but not for mid and top range). He recommended 29s for my 674cc kitted CB650 engine.

Lostboy Steve · « **Reply #113 on:** January 20, 2016, 09:23:58 AM »

Quote from: CB750 Cafe Racer Fan on January 16, 2016, 10:19:06 AM

I'd run it a couple more times on VERY hot.

Yes, I agree. lol it is a great idea though.

DMcD · « **Reply #114 on:** January 20, 2016, 10:20:37 AM »

Carbs are in Belfast, pay the tax tomorrow and pick them up. They will end up about £750/$1100. I could get 29s in the UK around £800, but the Dynoman ones have extra jets and 550 spacing.

Signed up for the local college hobby class last night, 15 weeks x 2hrs for £95. Works out at £3/hr for access to all their kit and materials (within reason) and staff to assist. Lathe/mills/cnc/tig/mig/plasma/laser etc. etc.

DMcD · « **Reply #115 on:** January 21, 2016, 12:10:46 PM »

Ooh they are pretty, had to bring them out of the box for a wee fondle

DMcD · « **Reply #116 on:** January 24, 2016, 01:32:21 PM »

The first tank I made was quite slab sided, so my youtube sheetmetal training showed that I would need an English Wheel to do compound curves. I bought a set of rollers off ebay and built my own frame. Been messing around with it and making some progress on scrap cutoffs. A lot to learn.

SOHC4 Cafe Racer Fan · « **Reply #117 on:** January 25, 2016, 12:25:49 AM »

That's the first one I've seen mounted to a wall.

DMcD · « **Reply #118 on:** January 25, 2016, 03:12:26 AM »

It just seemed easier than making a stand for it?

DMcD · « **Reply #119 on:** February 04, 2016, 10:09:50 AM »

First tank side looks promising. Hopefully I can get the other side to match.

DMcD · « **Reply #120 on:** February 11, 2016, 12:12:22 PM »

Ran out of argon tacking on the first side, doh!

Good news however is that I booked the ferry for the classic TT, so I now have a target completion date!

DMcD · « **Reply #121 on:** February 12, 2016, 03:40:49 PM »

The ebay monza style cap has a breather, but I decided to make one anyway to mimic the cr750 style tanks. Just used a few cuttings that were lying around the bench.

It looks a bit too tall, i'll trim it a bit before welding it in place.

Were the breathers this shape for a reason? Did the have a ball valve or something inside them?

RAFster122s · « **Reply #122 on:** February 13, 2016, 07:56:09 PM »

The pipe being open forward provides a pressurized tank (low pressure); that pressure is not significant enough to cause issues and it aids in fuel flow from the tank. The Control Line model engines would use a vertical pipe on the bottom and top and using a 45 degree angled to the line would provide low pressure to aid in fuel draw. It doesn't provide enough pressure to cause problems. It prevents the vapor lock or having a vacuum in the tank causing reduced draw as it sucks air back into the tank. Kind of like a vent to allow the bottle to empty rather than chug chug...like a 2L bottle when you up end it, it will flow liquid until it needs air to empty further and it sucks the liquid back in as it takes a gulp of air....the chug chug effect as we could euphemistically refer to it...

DMcD · « **Reply #123 on:** February 14, 2016, 03:08:44 AM »

Thanks for the advice, got the second side and rear fine tuned and tacked up last night. Sorry if this is getting boring, but it is a slow process.

DMcD · « **Reply #124 on:** February 26, 2016, 11:36:28 AM »

Tank bottom finished, just need to join the two parts now.

Got the paint too this week, very retro

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Author Topic: and so it begins, cb550k under the knife (Read 40148 times)