E: Engine 500 Innards

[brian gains]

did about 150mls with local section last week on a day run with more intermittent 'making smoke' with no obvious cause, also top end did seem to have a bit more of a noticeable rattle, all rebuilt about 4,500 mls ago and usual high oil consumption. So thought I'd bite the bullet put restrictor disk behind seal in timing chest cover and check push rod adjustment..

From what I.ve read I wasn't expecting push rods to be out of adjustment with such a low mileage, but they were and quite alarmingly so. They've been adjusted and I checked for debris in case as I'd read horror stories regarding cams and followers not being hardened and failing. Luckily no signs of debris , so now all I need concerm myself about is that I've adjusted things too tight and that will b*gger shonky quality controlled parts fitted.

However, what was most alarming was when the cover was removed a c/s allen headed bolt fell out followed by a c/s shouldered washer. joy of joys these were the retaining set up for the Alton recently fitted. Gods were looking down on me and TF nothing got chewed up while they were floating around.

Did I adjust pushrods correctly when I rebuilt top end and did I tighten down Alton pinion and use loctite I hear you say; of course I did!

Now I only mention this to my own self deprecation because if it can happen to me it can happen to anyone, so be careful out there. And to those that believe it can;t happen to them because they double check everything, well , sleep tight.

 

[greg brillus]

Perhaps the push rods were not seated in the sockets of the cam followers properly, this is a common issue.

 

[Martyn Goodwin]

The issue with the alton retaining screw is unfortunatly very common. The answer is to ensure that the threads are really clean then use loctite on them. Give it at least 24 hours to cure before running the motor

 

[bmetcalf]

Mine unscrewed and ruined a primary chain. I got some new allen screws, drilled and wired them.

 

[greg brillus]

On the twins the center screw is not long enough, I replace with longer and a dab of 243.

 

[Black Flash]

Glad to read that as I just fitted my new Alton gear without loctite.
This was necessary when I noticed that the ammeter was sometimes working and then not.
On dismantling I found that the hole in the old plastic gear had grown so much that it would turn on the shaft despite the key.
The only explanation I had for this was that I fitted the Alton without backlash and with temperature rising the pinion grew, more pressure more heat.... you get the picture.
Luckily I have one of these super gaskets thanks to Peter B so this should be an easy job
Bernd

 

[Marcus Bowden]

I tell these manufactures that they should used imperial threads when I get any foreign made part I drill and tap next size up so I do not have to increase my tool kit. imperial threads DO NOT slacken off like metric because of thread angle !
bananaman.

 

[Vincent Brake]

Mine unscrewed and ruined a primary chain. I got some new allen screws, drilled and wired them.

and now they rattle a bit?

 

[Bill Thomas]

did about 150mls with local section last week on a day run with more intermittent 'making smoke' with no obvious cause, also top end did seem to have a bit more of a noticeable rattle, all rebuilt about 4,500 mls ago and usual high oil consumption. So thought I'd bite the bullet put restrictor disk behind seal in timing chest cover and check push rod adjustment..

From what I.ve read I wasn't expecting push rods to be out of adjustment with such a low mileage, but they were and quite alarmingly so. They've been adjusted and I checked for debris in case as I'd read horror stories regarding cams and followers not being hardened and failing. Luckily no signs of debris , so now all I need concerm myself about is that I've adjusted things too tight and that will b*gger shonky quality controlled parts fitted.

However, what was most alarming was when the cover was removed a c/s allen headed bolt fell out followed by a c/s shouldered washer. joy of joys these were the retaining set up for the Alton recently fitted. Gods were looking down on me and TF nothing got chewed up while they were floating around.

Did I adjust pushrods correctly when I rebuilt top end and did I tighten down Alton pinion and use loctite I hear you say; of course I did!

Now I only mention this to my own self deprecation because if it can happen to me it can happen to anyone, so be careful out there. And to those that believe it can;t happen to them because they double check everything, well , sleep tight.

After a first build, The pushrods can need adjusting after a short mileage, It's the ball ends taking the shape of the cups, Top and bottom, That's why after any other work over the years, I like to keep the pushrods back in the same place they came out and same way up. Cheers Bill.

 

[vibrac]

I note from the detail in the original post that we are talking Comet here not twin - could this be the white 'Laxley Comet' whose owner had to disrobe the timing cover in front of all us likely lads? If it was that makes two because we were drawn to the fault by a knowledgable voice from the crowd who said "Mine sounded like that last week and it was the dynamo drive coming loose". if it wasn't that one then that makes three in under a month.
As a general rule follow Banana man stay imperial !