CB400F Frustrations - Not firing, low compression (Cyl Block now off)

[Bryanj]

From what i can see that is a set of exhaust valves not just one, replacing just one piston along with 4 sets of rings is a mimimum but a full set is better and as oversize cost the same as standard why not rebore if you can see marks, just my opinion its your money to spend how you wish

[hairygit]

Or go mad and get a 460cc bigbore kit from cruizinimage, a fairly good quality kit, and a lot cheaper than genuine parts!

[ManicGTI]

Yeah I pulled all four exhaust valves to take a look at them and give the ports a clean.  Aside from being filthy it looked in fine condition. I'm hoping my car valve compressors are the right size to get them back in again!

Don't get me wrong, I'm happy to do what work is required. But I don't subscribe to blindly changing everything. I'd prefer to get a view on the condition of what's there, if its scrap then so be it.

Having said that...I had spotted the cruizinimage kit on prev threads, could be a good solution. Any downsides aside from losing the taper to get the rings in?



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[hairygit]

Any good machine shop will do the boring and reinstate the tapers.

[ManicGTI]

Ah ok, I had thought from various threads (http://forums.sohc4.net/index.php/topic,96453.25.html) that the overbore meant there's not enough meat in the liners to have a taper with the 466cc kits.

BikePusher has an engine for sale at the moment as well...could be an option.

[SteveD CB500K0]

BikePusher has an engine for sale at the moment as well...could be an option.

Before anyone else jumps in...   you are joking right?

[ManicGTI]

BikePusher has an engine for sale at the moment as well...could be an option.

Before anyone else jumps in...   you are joking right?

I can't find much reference to bike-pusher on the forums, is there a reputation I should be aware of?

It's not my preferred option as I'd like to solve it myself. although looks like cruzinimage isn't selling the piston kits to UK at the moment.

[Bodd]

All I remember of Bikepusher was him asking why I was even bothering with my café racer build 

[tom400f]

Dave

bike-pusher is a breaker of 400Fs and has a healthy business on eBay. He joined these forums for a while and if you ask me it was only a matter of time. You can't be both poacher and game-keeper and indeed it all went sour with other members.

Spookily I flogged some furniture on ebay and the husband and wife team who came to collect it - he knows bike-pusher. Says he's a top bloke but tbh from what I could tell she was the one with the lights on and anyway if you're a dealer (viz pusher) you're a top bloke, right?

Anyhooo, sent you a PM. Looks like your bike broke a ring and this has taken out the exhaust valve as bits were expelled. Mild seizure marks on some pistons. Must be a rebore surely... Engine likely thrashed and should be stripped completely  On the bright side the bottom ends are built like a brick outhouse. Probably alright but you'd want to get in there, right?

Will ask my local friendly bike shop about engineering outfits.

[ManicGTI]

Sounds like a familiar story tbh, have seen similar things on car forums.

Actually the broken ring was on a completely different cylinder to the broken Valve.  It appears to have knackered the ringland on that piston in the process.  Not that that helps!

I'm going to work out what to do with the cylinders before I think about the bottom end.  Will see how much time I get.

All the input really is appreciated, thanks guys.

[AshimotoK0]

Re: 'bikepusher' ..... Well me included peed him off a bit and TBH it was because I can't bear to see really nice bikes broken for parts, which is a bit hypocritical of me  really because deep down I know I have bought really nice parts off nice bikes which should never have been broken up.

He starts stuff pretty low and daft bu**ers pay silly money for tiny bits and he rubs his hands together with glee  but some stuff looks OK and goes for a reasonable price sometimes, like engines and wheels etc that he sells and the description is pretty honest.

I too need to track down Cruzinimage, as I want to buy from them directly and have them shipped within Japan.

Ash

[ka-ja]

Hi AshimotoKO,
                          You could try---------cruzin_kx4305qgj@members.ebay.co.uk---------I can't be sure but I think the answer comes from Japan

[ManicGTI]

The reality is, mine is not that 'really nice' bike and I'm not going to pretend otherwise.  I'm taking the approach of 'getting a bit more life out of the old girl' and have some fun doing it, rather than aiming for a ground up resto.  We'll see how it pans out.

[tom400f]

OK I popped into Burwin Motorcycles this morning where I regularly go for tyres and MOTs to ask if they know of any engineering firms in norf London. "Not anymore" was their reply. Best they could come up with was http://www.galeacamchainservices.co.uk/ in Wickford.  Not local but may be reachable...

[ManicGTI]

Thanks for doing that Tom, appreciated.  These guys look worth a look as well, HTHoward in Slough: http://www.hthoward.co.uk/engine-machining-services/motorbike-engine-work/

I've had no luck looking for somewhere more convenient either :/