Engine teardown and inspection

[royhall]

There are a few pics that show the rocker cam contact area and at least 2 are done for. The cam also shows some damage that would stop me using it again. Can't really see the shells as they are still coated in oil and are a bit reflective.

The shells would look OK to a blind man

How did you know I sell blinds for a living.

[Trigger]

There are a few pics that show the rocker cam contact area and at least 2 are done for. The cam also shows some damage that would stop me using it again. Can't really see the shells as they are still coated in oil and are a bit reflective.

The shells would look OK to a blind man

How did you know I sell blinds for a living.

Don't ask me how i know these things 

[Bryanj]

No  (or is that yes) Master!!!

[matthewmosse]

Crikey, I'm now at my brother in laws where internet actually happens and the pictures load in less than 10 minuites a picture. Yeah, followers toast, gonna wear fast once through the case hardened layer. A fair geuss the cam lobes will have suffered. Deffinately start looking for a better example.

[matthewmosse]

Anyone got a good cam to photograph end on? Looking at full size, those cam profiles look kind of too rounded? I'm going from memory here as my cams are all at home where the internet is painfully slow and that is 180 miles away.
I've looked on ebay at engines, I could let a cb550 mill go for the same price as dk spares and at least test run it on a bench and if needed pull the rocker cover off to inspect the top end. I might even be able to get it dropped off in Leeds on my way to York if I or dad visits Gran at some point. I think based on photos so far that that engine is looking kida past where I would draw the line for a motor I wanted to save vs sourcing a better one, though it probably has good parts. My geuss is heamatite has blocked or restricted the oilways to the head causing partial oil starvation to the cam on one side, hence worn rocker faces, and I would be expecting similar camshaft wear. Checking the crank for wear is beyond my own expirience but I would not be surprised if run for long with the rockers wearing like that to find the oil being contaminated causing further wear.
Check the cam lobes for any sighns of a wear lip to the sides, one of the rockers / followers has sutch a ridge I think showing in one of the photos if I look carefully ( immage 6468, bottom left ). They should be pretty smooth, anything that would snag your glove or finger nail is probably bad news.

[cantarauk]

Thank you all for the replies which I have been reading a few times over and then researching when I have the free time. As mentioned I am fairly technical/mechanical but very new to a complete rebuild so all the advice comment have been really useful.

From what I can gather the consensus is that the engine has seen better days but what I need to know is it worth saving or getting a new one. I am not one to give up and agree with a previous comment about parts been expensive and scarce so would be prepared to invest time, effort and money if just to save this one.

Let me know your thoughts. In the meantime I am going to build a large To Do list which I will post should I decide to go the "save" route.

Glenn

[Bryanj]

everything is rebuild able if you have the cash and time, used engines are now getting scarce, expensive and may be just as bad. Some parts, like shells, are getting very difficult to source. What you really need is a US contact as spares seem easier over there

[matthewmosse]

Ap incorporated have supplied me with a few motors for cb550 over the years, worth giving them a call in case they have any in stock here or due shipping in. - being inporters of classic vehicles they might be prepared to come to an arrangement on shipping things from Usa. I think I still have engines I bought off them on the simple basis that it costs the same to bung one on a crate and ship it as a few. Milages are unknown but they say genrally very low. Like dk spares they don't open engines up to check internal health, at best, they will fire them up on the bike before breaking it and offer a 30 day garuntee provided you don't open it up and start messing - only fair as most dead engines I have seen are down to erronious rebuild work when stripped, though camchain tensioners disintergrating presumably from age has happened on a couple of engines over the years.

[cantarauk]

Hi,

Been a while since I posted here but been very busy on a large project at work and also very cold in the garage for this South African to do much work. After the initial advice I have taken the plunge to repair the engine I have rather than replace it with a different potentially same condition engine. That said I have been in contact with SEP in Kegworth to work on the all damaged parts getting them in a fit state ready for rebuild. The work they are undertaking is listed below and any comments/help/additions would be appreciated


- Camshaft
    - Check runout is within serviceable spec
    - Hard weld and regrind
    - Engineer camshaft journals to correctly fit camshaft

CrankShaft
    - check runout is within serviceable spec
    - measure and fit new bearings
- Conrods measure and fit new bearings

Cylinder head
   - Cut and reseat valves
   - Measure and replace springs if required
   - Change valve stem seals
 
To add to this  they are also blasting the bottom case and jugs which will save me a job later.

Once I get all the hardware back I will be sure to post some images for second option ions but as mentioned if there is anything I have missed of please do not hesitate

G

[florence]

The original engine for my bike was so worn in every part it was totally unusable and used more oil per mile than petrol.  In 1995 I relaced it with a low mileage one from DK.  They sent me three altogether.  The first two I stripped to inspect and sent them back as they were not as 'low mileage' as expected. 

However, the third one was very good.  DK told me it had done 7000 miles.  The top fin on the cylinder head was damaged but I'm not bothered by that sort of thing. It was very interesting to see the difference, everything inside and out looked new. I stripped it completely and rebuilt using new cam chain and tensioner and used the rebored barrel and pistons I already had, keeping the almost perfect DK one as a spare.  Since then I have changed the oil and filter every 1000 miles and adjusted things at regular intervals.  I have to say it's done very well so far, fingers crossed.

[cantarauk]

It has been three years since I updated here and to be honest with some large projects and been seconded out I have not really been home for the past two years.

Thanks for the contacts regarding engine replacements of which I did speak to them but in the end decided to go the difficult route and got the parts machined and where required sourced to re-build. I will be adding images soon of where I am at now that parts are coming out of storage as it is easier now with a bigger space to work.

I have started creating a shopping list to get the bottom done and so far come up with

Crankcase

3 x O-Ring         91315-044-000
1 x O-Ring         91319-300-000

Gear Shift Fork

1 x Spring         22421-040-000 -?
3 x Clip             24263-286-000
1 x Spring         24435-323-000 -?
1 x Spring         24435-323-020 -?
1 x Oil Seal        91201-292-003
1 x O-Ring         91304-216-000

Gear Shift Spindle

1 x Spring           24641-216-000 -?
1 x Oil Seal         91202-216-000 / 91205-HB2-772


Transmission

4 x CIR-Clip         90602-259-010
1 x Bearing          91001-283-003
1 x Bearing          91002-286-008
1 x Bearing          91022-286-016
1 x Oil Seal          91203-292-003 / 91203-292-005
1 x Oil Seal          91205-283-010
1 x O-Ring           91306-703-000

Primary Shaft

8 x Rubber Primary    23114-323-000 -?
1 x Primary chain       23131-323-000
1 x Spring                 28125-323-000
1 x Cir-Clip                90602-259-010
1 x Bearing               91005-323-004
1 x Bearing               91007-323-000
1 x Cir-Clip               94510-30000
1 x Bearing               96100-62050


Crankshaft

10 x crankshaft bearings - per requirement
8 x connecting rod bearing - per requirement
1 x Oil Seal              91201-300-003
1 x Oil Seal              91201-323-005

If I am missing anything please let me know and what to look out for. Then I was going to ask if anyone replaced washers when doing a rebuild or only if they are in a bad shape ?

[Bryanj]

Oil seal kit is better than individuals
O rings are frequently in gasket sets but depends on make( only difference 500 to 550 set is the clutch cover gasket)
An identical Kawasaki primary chain is half the Honda price.

If i think of anything else i will add it later

[cantarauk]

Thanks for the advice on the Kawa primary chain and at £48 some extra savings there which is great

As for kits - Vesrah or Athena ?

[philward]

What model Kawasaki as I will be needing one over the coming months

[cantarauk]

Looks to be the following from a very quick search -

Kawasaki GPZ GT Z ZR 550 GPX GPZ ZL 600

https://www.bikeparts-vintage.de/Primary-Chain-for-Honda-CB-500-550-650-Kawasaki-GPZ-GT-Z-ZR-550-GPX-GPZ-ZL-600

https://www.fowlersparts.co.uk/parts/view/92057-1011