CB650 "Parts Bin Special"

[andy120t]

I think I always knew that the solution to 'not starting' would be a carb strip and rebuild...I was just trying to avoid it!

I've had all the jets out and soaking in carb cleaner which loosened up most of the gunge. Amazing how rock hard and 100% blocked they all were - especially the pilot jets. Anyway, all cleaned up now- I've always understood it's a bad idea to clean the jets with wire, however the petrol in the pilot jets was rock hard...a bit of surfing told me that the wires on a wire brush would be narrorer than the narrowet pilot jet drilling/diameters - (from memory .16mm for the wire bristles vs .32mm for the tiniest pilot jet drillings....so I gently tried it out & found that the wire bristles easily fitted and helped me prod clean the gunge. By contrast, a safety pin and a needle (both of which look pretty narrow to the naked eye) were far too fat and would definitely have enlarged the holes.

Rsult of all this is that she fired up straightaway, without any choke - so a good result.

Still not MOT'd though - primarily because my fork seals (brand new and on pretty decent chrome stanchions) have leaked a river of fluid whilst standing in the shed. Given that the bike has barely moved since I put these in I can't understand why. A look at the parts diagram indicates that there may be a need for a washer between the seal and the seal circlip. I've not come across this before so am wondering if this will press it more tightly against the forks (?)  However, I can't think that this would be the case so I'm currently baffled.

[mick]

Hi Andy sounds like your making progress, i have used the wire out of sandwich bag ties as its very thin to clear pilot jets, don't know about the fork seals?,good luck with the rest of it  , cheers Mick.

[andy120t]

I'm considering the possibility that I've put the seals in upside down...never done this before but I was so intrigued by the amount of tissue paper stuffed in between the seal and the seal cover that I may have been distracted.....

Clearly someone couldn't stretch to the price of a new pair of seals at some stage!

Hopefuly get time to check this weekend.

[andy120t]

Well - Christmas, cold and various other excitements have got in they way - but I'm finally progressing again.

- First time round it was raining and miserable and having put in new seals, they proceeded to leak.

- Second time it started sunny then, as I was stripping the forks in the garden (again) it promptly turned cold and rainy and I got soaked. Re-fitted the seals, this time one seal leaked.

- Third time, I stripped and rebuilt the leaky one in the cellar and....finally....it has sealed.  Clearly the fact that I had laid in some Bandit 600 yokes to fit my 'spare' GSXR forks meant the old fork/seal combo new they were headed for the tip if they didn't work this time. (Alternatively, warm cellar and no rain trickling down my neck might have enabled me to fir them square rather than slightly wonky...never done that before though!)

Which just leaves - slightly spongy brakes and a slightly stripped fork bottom (which houses the end of the axle rather than having a nut) as potential problems before I'm properly on the road this year! Nearly there.

[Tomb]

Just enjoying reading through your build thread again Andy, couldn't help notice your frame.

It looks more like a K frame to me, I ain't an expert so forgive me if I'm wrong. The way I identify them is that the F frames' rear footrest loop is kinda like an equilateral triangle, whereas the K frames' loop is more longer and flatter triangle, if you know what I'm trying to say.

Frame

[andy120t]

I have to confess, I'm not an expert on the differences on the frames; I just read the log-book! I'll keep an eye out on any other 550's I see though.

.....took my Triumph 5TA for a succesful MOT last weekend so I'm re-energised for 2012......so now (almost) all bikes are MOT'd for the spring, but Parts Bin Special is choosing not to start and also leaking a lot of (nice, clean) oil from what appears to be the rocker cover / cylinder joint.

Two  possibilities:
- Not torqued down enough
- I missed out an O-ring during the rebuild

I'm hoping it's the first; don't mind if it's the second....anything else then who knows what it could be. Hope to get shed-time on Sunday to confirm.

[andy120t]

Unbelieveably, the last post on this thread was March last year ...and very little progress made since then; motiviation was flagging as my forks/seals would absolutely not seal...fluid was literally gushing out and the thought of another strip and rebuild in the 'outdoor workshop' was too much (having been rained on during the previous 2x fork rebuild.

..... on the plus side I now have a new house with large garage and I can work inside and out of the elements!

 So, when last parked up Parts Bin Special needed the following for MOT:
- to put in working fork seals
- stop a leak from one of the carbs (probably a stuck float / overflow)
- be reasonably happy with the noisy exhaust
- I also noticed that I had an oil leak from one side of the cylinder so I may have missed an o-ring from an oil passageway during the rebuild.

Feeling remotivated I've now stripped one fork and rechecked all the dimensions of the seals and the stanchions; then checked my original order form Wemoto - correct seals had been supplied, so they mush be faulty. David Silver then supplied some pattern parts and these have gone in .... and the forks are sealed now. Result! I need now to complete the second side and reinstall works / wheel etc.

In the picture (if attaching works!) the working seals are in the packaging and have springs in - they've been pretty hard to insert into the forks. The third one is the leaky one and has no visible spring in it - just wondered if this is the reason why it doesn't work at all. Regardless, it was relatively easy to install so maybe jsut poor manufactuing tolearances.

[LesterPiglet]

No pics. You may want to try www.photobucket.com to upload your photos, from there you can share to any site.

[andy120t]

Piccies from photbucket...
leaky seals - although this doesn't actually show how horrendous they were.....imagine that whole area swimming in fork fluid...


..and lovely new seals from David Silver. The un-packaged one is the old one and doesn't have a visibile spring in it...and it was nowhere near as hard to install as the DS ones.