Author Topic: CB650 retro-racer (Read 42695 times)

Zaipai · « **Reply #150 on:** May 11, 2010, 04:20:14 AM »

Quote from: scunny on May 10, 2010, 11:28:20 PM

will do, have a spare one but haven't checked it out yet, hopefully if I've kissed a valve it better be the exhaust since I bought 2 sets when doing the motor up

Man I hope you haven't kissed a valve, or at least if you have then I hope its the ones you have spares for..

.: Scott :.

The_Crippler · « **Reply #151 on:** May 11, 2010, 06:34:13 AM »

Quote from: Zaipai on May 11, 2010, 04:20:14 AM

Quote from: scunny on May 10, 2010, 11:28:20 PM
will do, have a spare one but haven't checked it out yet, hopefully if I've kissed a valve it better be the exhaust since I bought 2 sets when doing the motor up
Man I hope you haven't kissed a valve, or at least if you have then I hope its the ones you have spares for..

.: Scott :.

Okay...excuse the dumb question - but I haven't heard this term before. "Kissed a valve?"

Frankenkit · « **Reply #152 on:** May 11, 2010, 08:54:02 AM »

where you jump your timing and a piston hits a valve that's still open.

The_Crippler · « **Reply #153 on:** May 11, 2010, 11:46:10 AM »

...and what is the end result? (I mean, aside from a busticated motor.)

scunny · « **Reply #154 on:** May 11, 2010, 11:58:09 AM »

worse case holed piston. hopefully just a bent valve. I don't know when the adjuster went, the bike was running great and no bad noises. started it up let her idle for a while then turned it off. when I tried to restart it I initially blamed the battery and tried to push start.

The_Crippler · « **Reply #155 on:** May 11, 2010, 01:47:14 PM »

Thanks for the explaination. Learn something new, etc.

I really hope your case isn't anything serious.

scunny · « **Reply #156 on:** May 14, 2010, 11:02:25 PM »

front cam chain holder snapped in half, no sign of scoring on it or the tensioner itself. no 1 inlet valve has enjoyed tapping the piston and is slightly bent, other than that no damage.

photos when it's light outside. very strange. I've got a spare so no bother there but will contemplate my navel for a while, could my cam chain have suddenly stretched ? doubtful, only splitting the cases would show that so navel gazing it is.

Hush · « **Reply #157 on:** May 14, 2010, 11:40:29 PM »

More likely your adjuster slipped enough to let the chain do that, never have been that keen on the stock cam chain adjuster, one little nut on a thread seems under engineered.
Jaffa's Suzi 400 has a cam chain adjuster so big you have to remove the starter motor to get it out, I know cos I had it off so often I actually made special tools to make it easier.
Good luck with the rebuild Scunny.

scunny · « **Reply #158 on:** May 22, 2010, 06:43:23 PM »

650 has taken a backseat in the build sequence, I've got 3 bikes in bits and bench space is a bit crammed. will finish the 250 first.

Hush · « **Reply #159 on:** May 25, 2010, 12:19:08 AM »

Good Kiwi logic.

manjisann · « **Reply #160 on:** May 25, 2010, 08:19:13 AM »

Sounds like you already have the parts you need, glad to hear that, and hope everything goes well for you!!

I'm gonna be stripping one of these engines down soon, would you mind taking pics while you do this?

Anyhow, good luck!

Brandon

scunny · « **Reply #161 on:** June 16, 2010, 08:23:28 PM »

will take photos but they are pretty simple. removed the pistons today(makes mok ups easier) so I can put the top end back together and try to figure out what happened. the cam chain appears to be looser on the cam sprocket than an old set I have lying around. did my new chain go poop, will think this thru otherwise the motor has to be split and new chain put on........

Hush · « **Reply #162 on:** June 17, 2010, 12:50:44 AM »

Ouch, our 650 cam chains are one piece eh Larry!

scunny · « **Reply #163 on:** June 17, 2010, 02:04:38 PM »

DSS lists a "soft link" cam chain joiner. I might order a couple and have a play. I am unhappy how much the links can be lifted off the sprocket.
some thinking required.

Hush · « **Reply #164 on:** June 17, 2010, 10:49:13 PM »

Sounds like your adjuster mechanism has reached the end of its' adjustability.

scunny · « **Reply #165 on:** June 18, 2010, 07:39:14 PM »

removed oil pan, dumped the bike on it's side and lo and behold the cam chain adjuster is not seated in it's pocket. this may also have happened when I rebuilt the motor, more thinking required.

Hush · « **Reply #166 on:** June 19, 2010, 12:39:38 AM »

Ah I suspected as much mate, I've got to say that after working on a lot of different makes of bike over the years that the 650 has one of the flimsiest looking cam chain adjusters I have ever seen.
The one on my partner's GSX400 is about the size of our starter motors and her bike is only a twin!

scunny · « **Reply #167 on:** June 23, 2010, 07:31:03 PM »

still waiting for my new cam chain and soft links, so decided the bent valve better be replaced now, luckily it turns out the bend was right at the head, not along the stem so the valve guide is good to go.

Rich361 · « **Reply #168 on:** June 23, 2010, 07:51:22 PM »

Hey Scunny,

Sorry to hear about your bike mate!!!

I don't know if you have heard about this website.... http://www.plenternz.com/

I found it while searching for front brake for my bike... Ha Ha yes still looking, wondering what to do??....

They sell OEM Parts and the great thing is it's in Lyttelton, Christchurch!!!

They seem a little bit expensive but when you consider you don't need to apply shipping costs etc to it.... probably not too bad...

Cheers

Rich

scunny · « **Reply #169 on:** June 23, 2010, 08:12:56 PM »

cheers for that Rich, never heard of them before, and more than one supplier is good. no problems on the shipping costs, DSS love me.

scunny · « **Reply #170 on:** June 23, 2010, 08:16:39 PM »

no worries on the bike. if they are gonna go, in the driveway is the place to do it. she was coming apart to redo brakes and suspension anyway but tried to jump the que, I'll never get my 400cc twin flat tracker going at this rate.

scunny · « **Reply #171 on:** July 07, 2010, 06:58:21 PM »

bloody winter. have experimented with the soft link idea and the jury is still out. might just split the motor anyway but not today, I'll have to tidy the bench enough to fit a complete tear down.

Hush · « **Reply #172 on:** July 09, 2010, 12:05:28 AM »

That sux mate but with the winter well and truly here there aint many good riding days anyway.
I'm hoping to get a ride in this weekend, the rain has finally stopped after a solid week.

scunny · « **Reply #173 on:** July 24, 2010, 06:18:02 PM »

ah well, got another 250 motor buttoned up now back to the 650.
split and rejoined the new cam chain, no problems there.
now back together we go. for the 650 owners out there, fitting the rings and holding the block isn't easy, we don't have studs to control things. solution is some 8mm threaded rod cut to 200mm lengths.

manjisann · « **Reply #174 on:** July 24, 2010, 07:28:49 PM »

Good to see you are making progress and thanks for the tip on the threaded rod. I just found a hole in my upper and lower case, think I must have thrown a bearing or something

so I'm looking at a complete rebuild on that engine once I've sourced some cases. Got pics of the carnage on my thread if you'd like to see em.

Brandon

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Author Topic: CB650 retro-racer (Read 42695 times)