AJS & Matchless Owners Club

Both of my '55 and '56 G80CS's have breather hoses attached to the pushrod adjustment cover. Some people say they are absolutely necessary to vent rocker box pressure, and some say they cause other problems. Who knows. ahahaha.

This issue does sound a lot like the drains in the head are blocked or something. Be interested to hear what you find.

Well Marty you were the closest! Pulled it down today and the bottom O rings had mushroomed out into the pushrod tubes and blocked the tappet drain holes. Absolutely nothing to do with anything Ken had done, I didn't expect that it would be as his work is second to none. He's been in contact offering to strip and rebuild the motor for free but I'll have no problems putting it back together. He's never heard of that issue ever arising before so at least I'm unique. Guess I'm lucky no damage has been done.

Oh yes you are unique Rob! (good news you have identified the problem)

clive wrote:Oh yes you are unique Rob! (good news you have identified the problem)

Hmm! I think I'll have to digest that reply!

ajscomboman wrote:Well Marty you were the closest!

Hi

Missed my post on page one then

"Have you done anything recently that could result in a blockage to the return galleries at the bottom of the push rod tubes?"

Glad you've got it sorted.

Regards Mick

If you use viton o -rings, you will never have this problem.
regards Poul

Mick D wrote:

ajscomboman wrote:Well Marty you were the closest!

Hi

Missed my post on page one then

"Have you done anything recently that could result in a blockage to the return galleries at the bottom of the push rod tubes?"

Glad you've got it sorted.

Regards Mick

So I did, well you can both have a prize. I've done nothing to the motor except lap the head in as it started to weep last year. Done hundreds of miles since then, including 80 the week before the IWKR weekend and all was well. I guess they've been swelling for a while and the latest round of baking hot weather and oil was enough. It's a bit of a bugger as the bike has been running well right up to that point. Still it's on the way to being fixed.

ajscomboman wrote: It's a bit of a bugger as the bike has been running well right up to that point.

They all do that, Sir.

(The gas in my motorhome always runs out when I'm in the middle of cooking something ).

ajsph wrote:If you use viton o -rings, you will never have this problem.
regards Poul

I think I have a similar problem developing on my 350 though it has shown up as sudden copious leeks - seals at base of pushrod tubes are probably 4 years "old". What size Viton seals are required, do you know Poul?

Hi Ron
I don`t know the correct size for your 350, but on my 1959 18CS I have used 23 x 3 mm and 19 x 5 mm, sorry about mm.
Regards Poui