Chasing the smoke

[PaulD]

Mmm that sounds interesting, the guy I bought my bike off said he had rebuilt the motor with new pistons & rings but in the spares box I got with the bike I found only two pistons. One had damage to the crown (obvious valve contact) but the other seemed good. I’m wondering if some of my rings have been fitted upside down? Time will tell when I pluck the courage up to strip it.

[stockcar]

Yes top rings are 'compression' seals and the (normally 3pce combo) lowest ring is the oil ring to stop oil being passed up into the combustion chamber

[spondonchris]

that looks like a genuine head gasket to me

[PaulD]

that looks like a genuine head gasket to me

+1 It looks like the one I bought off you Chris?

[katmarch]

http://www.duncanracing.com/TechCenter/ ... -24-05.pdf

This explains rings, mark is on top face & should always be on the upper surface, the outside edge of the compression rings are not square, if placed upside down they will not seal correctly, the best 'bedding in' will be when the ring is so worn it is a square edge, many many miles.

Steve

[Kryten]

that pretty much sums it up.
Had loads of fun/practice with Royal Enfield 250’s back in the dim and distant past with how to rebuild engines!

[PaulD]

Next stages seems to be lots of measuring with quite specialist equipment, bore mic for the cylinders, placing ring in cylinder and measuring gaps.

If this is all fine then its looking at valve guides and that looks to need lots of measuring equipment as well.

Think I could probably buy a new Kat at this rate.

Welcome to my world
Luckily I have a bore mic or two so that bits no problem. I just need to get my arse into gear, bite the bullet and make a start on it. Being honest I’m thinking of doing what the PO did to me and palming it off on some other gullible fool then go and buy a
nice Hayabusa

[Uncle Bob]

I sold my first 1100 Kat for £2100 in 2004(ish) after getting a few too many points on it, so decided to put temptation out of harms way. Then regretted it but managed to buy back into ownership again in 2010 for £2500 (private sale). If I had waited to buy in now I'd be a bit gutted.

That's just buying old bikes though - TZR I bought was good for 900 miles but then spat it's dummy (wasn't really sold as described but as i got from Holland not much I could do). The X5 again was mis-sold (no engine work done internally at all) and I did get some cash back on that. Both were from dealers!

The Swiss 1100 I bought I think was a peach for £3000. Still a few issues to resolve (fork oil has leaked out of anti-dive). Seller was really nice and helpful.

Good on you Blix and persevering and also for doing this yourself - at least you'll have 100% confidence in the end result this time.

[Kryten]

Hi Mick

Grabbed these images from my workshop manual. OK so it's for a "Boat Anchor" but it's still relevant

I think I have a valve spring compressor in the shed. I'll have a look and see next week before the mice bed down for the winter and let you know! you're more than welcome to borrow it if I have and I will send it up to you with your Ventura side rails.

[stockcar]

A local engine shop will be able to measure eveything (or should be able to) for a little exchange of beer tokens....