AJS & Matchless Owners Club

How often should the sludge trap be cleaned out? I have had my bike since 2000 and never done it and I'm thinking that perhaps it is about time I tackled the job as the bike has now done in the excess of 30,000 miles. What does the team think?

I have never cleaned a sludge trap. Where is it?

Hi John

I have just cleaned out the sludge trap on my Sunbeam S7. I was not going to bother but the engine was so far apart that I decided to have a look and I am glad I did. The crank was so full of sludge that it was just starting to block the oil holes to the big ends and the journals had started to score and the big end shells were back to the copper in places.
I am not sure how many miles it had taken to fill the trap but a fellow club member has stripped his Sunbeam and cleaned the trap every 25000 miles - he has done it four times! He runs on straight 50 non detergent oil.
I am not sure how much sludge can be accommodated in your crank trap but at 30,000 miles I think it would be wise to have a look as you cannot be sure it it was cleaned out before you bought it.

Jim

Missed you Monday Jim, just Graham and myself so I'm beginning to think it's about time to call it a day.

Rob Harknett wrote:I have never cleaned a sludge trap. Where is it?

Rob, it's on the crank of a twin, there are two screws in line with the big ends, these are usually centre punched, removing the screws reveals a tube which catches debris from the oil on its passage to the big ends, if this is left too long it can block or restrict the flow to the big ends, causing all sorts of problems, ie wear and expense.

Flash wrote:

Rob Harknett wrote:I have never cleaned a sludge trap. Where is it?

Rob, it's on the crank of a twin, there are two screws in line with the big ends, these are usually centre punched, removing the screws reveals a tube which catches debris from the oil on its passage to the big ends, if this is left too long it can block or restrict the flow to the big ends, causing all sorts of problems, ie wear and expense.

Thanks, I have always had singles. Apart from an A10 BSA back in the 60's. I do have a G12 CSR but hardly ever use it. I do not recall hearing in conversation, about cleaning sludge traps.