1960 Matchless 350 piston replacement and engine inspection

Information relating to the Matchless G3 or AJS Model 16 350cc Heavyweight
Mick D
Posts: 2886
Joined: Mon Mar 24, 2014 5:44 pm
Location: Aberdeenshire

Re: 1960 Matchless 350 piston replacement and engine inspect

Post by Mick D »

DaveSlow wrote:How would the oil pump etc get cleaned up if I flushed the cases?
Hi

You need to remove the oil pump plunger in order to inspect it's bore for damage and debris - clean it at the same time.

The practice of not splitting the cases for inspection and cleaning is very flawed in my opinion, it's not a difficult engine to work on and splitting the cases gives you the peace of mind that you've cleaned out the debris and identified / rectified any faults. Do yourself a favour and tot up the cost of a wrecked bottom end due to a missed bit of debris and half a days work :o :o

Regards Mick
AFSMatchie61
Posts: 60
Joined: Sat Oct 01, 2016 7:34 am
Location: Scotland

Re: 1960 Matchless 350 piston replacement and engine inspect

Post by AFSMatchie61 »

It's certainly the most rigorous approach Nick and as I have the whole winter that is what I'll do. If I was in a hurry I'D just clean it out and take the risk but the riding season is all but done anyway.At this rate I'll take the whole winter to get it done :D
How bad does the bore look to you?
Cheers
Dave
Mick D
Posts: 2886
Joined: Mon Mar 24, 2014 5:44 pm
Location: Aberdeenshire

Re: 1960 Matchless 350 piston replacement and engine inspect

Post by Mick D »

Hi Dave

The way I look at it is that you need to replace the piston, so start there.

Measure the bore to determine if it is standard or has been re-bored. Hopefully there will be enough 'meat' left to allow it to be re-bored to remove the scoring, (I see no point in honing a worn bore and then fitting a new piston). Buy a piston to suit the general dimension of the repaired barrel THEN get the barrel re-bored to suit the piston, (clearance as detailed by the manufacturer).

Mucking around with the barrel and then trying to source a piston to fit is just making life difficult.

Regards Mick
JEAN-NOEL
Member
Posts: 601
Joined: Wed Oct 12, 2005 10:45 pm
Location: FRANCE

Re: 1960 Matchless 350 piston replacement and engine inspect

Post by JEAN-NOEL »

Hi Dave,
I agree with Mick. Engineers advertising in the Jampot are knowing very well our bikes, and they are able to match your barrel with different pistons makers. If you find a perfect piston in original size, they could reline your barrel to suit.
Triumph-Legend
Member
Posts: 476
Joined: Sat Oct 26, 2013 9:09 pm
Location: CAMBRIDGESHIRE UK

Re: 1960 Matchless 350 piston replacement and engine inspect

Post by Triumph-Legend »

DaveSlow wrote:It's certainly the most rigorous approach Nick and as I have the whole winter that is what I'll do. If I was in a hurry I'D just clean it out and take the risk but the riding season is all but done anyway.At this rate I'll take the whole winter to get it done :D
How bad does the bore look to you?
Cheers
Dave
Dave, as you are planning to go for a strip down, get the piston and check that small end/gudgeon pin fit while the crank is out of the case. This especially if you are going to replace the B/E. this will allow the small end bush to be reamed parallel to the big end axis.

As the bike will largely be in pieces for a while it may be a good time to give the g/box, clutch, dynamo, mag and other components a look over. Who knows it could save a lot of time and future hassle.

You are dead right, not a lot of riding through the winter months and with the current bug going around you will need something to keep you sane.
Hmm, Broke, but sane. :rofl:
Locked