Author Topic: 78 CB550 full rebuild (Read 6088 times)

sboubel · « **on:** July 31, 2014, 06:08:46 PM »

Hello everyone,
I have been on here for a while reading and getting ideas and thought I would share my project. I have a 1978 CB550 that my Dad bought brand new when I was little. Over the past few years I have paid several repair shops a lot of money to get this thing going and every time it was done it was ok for a short time and then was just back to not running well at all. I have decided that I am going to rebuild this thing from the bottom up and add a little HP in the process. Here are some pictures of the bike before I started and the disassembly process.

sboubel · « **Reply #1 on:** July 31, 2014, 06:13:54 PM »

Here are some pictures of the engine disassembly.

sboubel · « **Reply #2 on:** July 31, 2014, 06:17:45 PM »

After looking at everything I decided to upgrade using the Dynoman Stage 2 kit which includes:
DP592/61s Hot Street Piston Kit
WebCam 358b Camshaft*
KPMI Valve Springs
DP SHP Clutch Kit
Chrome Moly Cylinder Studs
Vesrah Top Gasket Set
Cometic CFM or MLS Head Gasket

I also needed a new primary chain and cam chain and decided to replace all of the seals in the lower case as well as a few other misc. parts. Here are some of the goods.

sboubel · « **Reply #3 on:** July 31, 2014, 06:28:38 PM »

Before and after pics of valve job. I ordered OEM valve stem seals and then realized that the gasket set I ordered before had them...well I guess OEM is better or at least that makes me feel better.

Tews19 · « **Reply #4 on:** July 31, 2014, 07:20:58 PM »

Wow you work fast! That bike looks minty before tear down! Did you already order dynoman pistons?

sboubel · « **Reply #5 on:** July 31, 2014, 08:01:56 PM »

No I didn't. I realize now after I had it done that I should have done that also. Any other suggestions? I have disassembled and cleaned the engine cases and internal parts and have had everything painted. Here are the empty cases mocked up. I want to polish all of the side covers which I think will look really nice with the black.

sboubel · « **Reply #6 on:** July 31, 2014, 08:08:20 PM »

Tews19,
Yes I did order them and I have had them for a few months, should I be worried? I started this project in January so the progress is not as fast as the pictures make it seem. The bike looked good from a distance but the frame had a lot of scratches and rust and the engine cases were really ugly. I plan on having the frame powder coated, I hear that is best and I found a place that can do it a damn good price.

SOHC4 Cafe Racer Fan · « **Reply #7 on:** July 31, 2014, 08:16:43 PM »

sboubel,

Definitely powdercoat the frame. It is more durable than painting. If you plan to make any modifications to the frame (detabbing, bracing or mounting an oil cooler), now is the time to mock it up BEFORE powdercoating.

As for the motor, you did a nice job of cleaning the cases. Too bad you skipped porting. That would really take advantage of the increase in displacement and cam by improving the intake flow via your brand spanking new valves. It's not TOO late, but you will ended up removing the valves and reinstalling them to port it. I would do it now while you can. This will really wake up the motor. You should also port the manifolds to match.

The bike has a little bit of wear and tear but it was in damn good survivor shape. It looks like it sat garaged for most of its life. What are your plans, aside from the engine rebuild? Are you keeping it mostly stock?

Tews19 · « **Reply #8 on:** July 31, 2014, 08:18:25 PM »

What's the plan for the tank and side covers? My first CB was a 78 550 with the black tank and side covers. Gpt it for 700 buckeroos! God I loved that bike. I wish I never sold it.

Get the frame and small tidbits powder coated for sure. Here is a pic of my 78.

sboubel · « **Reply #9 on:** July 31, 2014, 08:38:01 PM »

CB750 Cafe Racer Fan,
Interesting you mention mounting an oil cooler because I have wondered if the engine mods I am doing if I need one. I have seen a couple posts on them but haven't seen anything that made me decide I needed one. At this point I want to do it right and make it last as long as it can so any advise is appreciated.

I haven't decided what to do with the rest of the bike cosmetically, I don't want to do anything dramatic I don't think but I have seem some really sweet CB550s on this forum that are dramatically customized.

sboubel · « **Reply #10 on:** July 31, 2014, 08:55:51 PM »

calj737,
When I took the cylinders to be bored I asked if they wanted all of the pistons and they only kept one, it is impossible to find a place in SATX that does any machine work on motorcycle engines so my options are actually limited to one place. What kind of place does the coating that you are suggesting?

sboubel · « **Reply #11 on:** August 04, 2014, 01:03:40 PM »

So I cant find a place in San Antonio to do the porting work. Does anyone have any suggestions? How much should that cost and what will it ultimately do for me? Also will I need to order any new parts like larger valves or something? I really dont know exactly what is involved in the porting process.

Tews19 · « **Reply #12 on:** August 04, 2014, 03:07:26 PM »

Another option that you could do is a 650 engine swap. 20 percent increase in HP right away. It's a direct bolt in and only weighs 2 lbs more then a 550 engine. It would be cheaper this route then doing the head work and boring. I did the head work and boring only because there isn't a motogpwerks 4-1 for a 650.

Tews19 · « **Reply #13 on:** August 04, 2014, 03:46:36 PM »

Sorry I should have been clearer. Swap a 650 engine with harness into a 550 frame. Heads are different on a 650 then a 550. From what I've read they flow a lot better. Hence the dramatic. HP increase with not much displacement increase.

sboubel · « **Reply #14 on:** August 06, 2014, 04:24:52 PM »

I have already had the cylinders bored, valves done, ordered a lot of upgrade parts, and the engine painted so I am in too deep into this engine to abandon it. At this point I guess I really want to know if the cost and inconvenience outweigh the benefits. Does anyone know how much a porting job normally runs?

sboubel · « **Reply #15 on:** August 11, 2014, 04:45:05 PM »

I took the bowls off the carbs and took some pics. Is this normal for a bike that has sat for about 2 years? I don't think there should be that must rust in there, am I right? I was planning on getting the rebuild kit at the link below. Anyone used this one and is it good?

http://www.dimecitycycles.com/vintage-cafe-racer-caferacer-bobber-brat-chopper-custom-motorcycle-engine-parts-honda-cb550-carburetor-rebuild-kit-18-2422.html

sboubel · « **Reply #16 on:** July 26, 2015, 04:37:37 AM »

So after a long break I have picked this project back up. I am reassembling the engine and after putting on the cylinder jugs I have a 1/16" gap between the bottom of the jugs and the engine casing and I am not sure what is causing it. I have added some pictures to show the gap.

Can anyone let me know if this is normal due to the o-ring gaskets on the bottom of the piston cylinders or am I doing something wrong?

bwaller · « **Reply #17 on:** July 26, 2015, 05:10:27 AM »

Are you using the correct dowel pins...the ones with the oil restrictors?

sboubel · « **Reply #18 on:** July 26, 2015, 05:36:18 AM »

Yes, I am using the ones that look like a nozzle.

P.abrera · « **Reply #19 on:** July 26, 2015, 05:56:30 AM »

You sure the dowel pins are the right way up?

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sboubel · « **Reply #20 on:** July 26, 2015, 06:56:53 AM »

I just verified that they are in right, the larger end with the cone shaped end is down and the flat end is up.

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Desert Dan · « **Reply #21 on:** July 26, 2015, 11:16:20 AM »

On the 500 and 550 the cam chain tensioner is a real PITA and when installed correctly will keep the cylinders from sitting flush until you bolt down the head.

sboubel · « **Reply #22 on:** July 26, 2015, 11:23:48 AM »

Thank you Desert Dan, I was hoping that would be the case.

Thank you everyone for the input!

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Desert Dan · « **Reply #23 on:** July 26, 2015, 12:21:04 PM »

Quote from: sboubel on July 26, 2015, 11:23:48 AM

Thank you Desert Dan, I was hoping that would be the case.

Thank you everyone for the input!

Sent from my iPhone using Tapatalk

Glad I could help out, just be sure the bottom of the cam chain tensioner assembly is correctly located in it's nook in the case before you go bolting the head on. Good luck with the rest of your build.

sboubel · « **Reply #24 on:** October 24, 2015, 11:57:12 AM »

Hey guys,
Well I am finally back at it and I think I have run into a massive issue. The 3 bolts indicated in the picture will not tighten down and I am not sure what could be going on. Any ideas would be appreciated.

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Author Topic: 78 CB550 full rebuild (Read 6088 times)