Crank movement - explains the knocking!

[Muppet]

nominal play imo

[wack 63]

It's impossible to go by the video, it needs the mag housing on then check. Even new drive bearings have a bit of play especially C3 and 4's which take the tolerances up when warm.

[alanscottj]

Even with the mag housing on the crank still moved in and out. Have taken the bearing out and there is an awful lot of movement on it, I'm pretty sure it is the drive side bearing. I'll know for sure when I put a new one in there anyway. Crank looks ok, and mag housing looks ok.

Which is the best bearing to use? The one that was in there was made in Korea but couldn't see a name on it.

[rosscla]

One that the manufacturer has put their name on would be a good buy.

FAG or SKF but get it from a reputable dealer not eBay - there are forgeries about.

http://www.bearingboys.co.uk/search.cgi?search=6305

[alanscottj]

One that the manufacturer has put their name on would be a good buy.

FAG or SKF but get it from a reputable dealer not eBay - there are forgeries about.

http://www.bearingboys.co.uk/search.cgi?search=6305

Thanks Rosscla, I'll get FAG bearings and I'll change the mag housing bearings and seals whilst I'm at it. Lambretta Upgrades do the FAG bearings and a TS1 gasket set, might also replace the drive side oil seal plate whilst I'm at it.

[wack 63]

My mate is a bearing stockist and supplies me, I queried why FAG have Made in India, Korea etc on them now and his supplier says that they are now made all over but to FAG quality control.

[alanscottj]

My mate is a bearing stockist and supplies me, I queried why FAG have Made in India, Korea etc on them now and his supplier says that they are now made all over but to FAG quality control.

Thanks, looking back, I think I only used normal bearings instead of 'high load' bearing ones Maybe that's why they have only lasted a thousand miles!

[eden]

mag bearing more likely the reason for movement.

[Chris in Margate]

If the crankshaft was suspended between 2 bearings and 3 oil seals and you could move it before stripping out the mag housing then my assumption from afar would be that the mag side bearing has gone. Whatever; you've split the engine so you will have peace of mind when rebuilt with all new components.

[alanscottj]

If the crankshaft was suspended between 2 bearings and 3 oil seals and you could move it before stripping out the mag housing then my assumption from afar would be that the mag side bearing has gone. Whatever; you've split the engine so you will have peace of mind when rebuilt with all new components.

Absolutely, as you say, peace of mind. Might as well do them both. And whilst I have had the engine apart I have been able to repair some damaged threads. Also, when I order the new bearings, seals etc, I'll be ordering from a reputable dealer so I know everything is the quality it should be.

I must say I have learnt an awful lot from building this engine, and I've learnt a bit more since the last rebuild, so this build will be much improved. I have also bought torque wrenches that will cover all nuts and bolts so everything will be torqued properly. Also, I wasn't happy with the squish on this Engine, it was just slightly out (bigger) than recommended so it will give me opportunity to remedy that.

Everyday is a school day! Thanks for everyone's help so far