Topic: Apologies (CB550)

[flatlander]

yes it's the same product. sorry, didn't realise you're in the UK.
i would expect it to fit both F models.

[IRISHCBRACER]

http://www.cb750cafe.com/blog/stainless-steel-4-into-1-exhausts-for-cb500-cb550-now-available-399-only/

[Chappy]

Afternoon all, it's been a while.

I thought I would revisit the seized engine. I took the rocker cover and split the chain with a bicycle chain splitting tool and removed the camshaft and cylinder head.  Number 1 pistons looked a bit gunked up so I put pentrati G oil onto all for.  Made a cup of tea and let it soak for half and hour.  I then poured some petrol onto them, and lit it.. cleaned them up, added more penetrating oil and put a spanner onto the crankshaft. It moved!

I then pulled the cylinder block and removed the pistons to let them soak for a bit. The engine itself (apart from it being seized when I obtained the bike is immaculate (no wear marks or gauges visible anywhere)

Could I have some advice for the next steps - cleaning the cylinders. 

 

[Chappy]

     

     

[Chappy]

Bugger.  I'll give it a rub.. and post the results.

Cheers : thumbsup :

[Chappy]

 

I spent 5mins on each with 800 wet and dry, there is visual scarring but most of the corrosion was built up on the cylinder rather than into it if that makes sense.

What's the verdict? 

: drum-roll :

[b52bombardier1]

The verdict? Find a truly competent machinist with calibrated measuring tools and follow his advice to the letter. He should measure for next oversize diameter, taper and out of round condition.  Don't buy anything until he tells you what to purchase.

If he's really good, he won't start your bore until he has that new oversize piston in hand. This allows him to very precisely tailor his bore to that particular set of pistons. The tiny clearances needed demand this level of precision.

Rick

Sent from my SAMSUNG-SM-N900A using Tapatalk

[RAFster122s]

Align bore them as well to restore about 5% loss because of the drift of material used for the cooling fins on cylinders.  That might require it to go up a size... so, measuring is definitely required.