Broke the connecting rod on my 1967 Century after running without cooling. I would like to get a tool into the cylinder block passages without removing the head? Any suggestions? I have tried penetrating oil and may try teapot descaler if I can find out what it is called in the US.
I notice some heads have studs instead of bolts. It looks like this was on the early models?
I also noticed that the 105 cc models with the large props seem to have more cracked blocks? I assume that its a matter of overloading with reduced cooling.
I would appreciate any thoughts on these issues. Thanks.
Clogged water passages
Moderators: John@sos, charlesp, Charles uk, RickUK, Petergalileo
Re: Clogged water passages
There is no way you can get any tool into the passages in the block without first removing the cylinder head. The first passage - the outlet - runs parallel with the cylinder head so the first thing your tool would have to do is effectively double back on itself.
So the head will have to come off - yes you're right some earlier ones are machine screws, nuts are usually easier to undo.
If they are not corroded they will still need a good soak in something that'll penetrate, diesel is good. Then they may need heat. Once the head is off you will see the extent of the problem. Sometimes to blockage is made of softish crumbling stuff, sometimes it's like concrete. Either way you will have fun - possible for hours - chipping it all away.
Descaler doesn't do the job, nor penetrating oil. It's a combination of rust and mud; baked by the overheating.
In my experience it's Silver Centuries that are the worst culprits for cracking their blocks - is that what you mean? (There was no 107cc - but all the larger ones are 102cc.) It was to do with thin walls as much as anything else.
If you siezed it have a good look at the bore.
Once you have your block cleaned up you can use the old head gasket once annealed if it's not too damaged, but new ones are available from John on the main S.O.S. site, you can get a con rod from him too. I don't know about postage.
Let us know how you get on
So the head will have to come off - yes you're right some earlier ones are machine screws, nuts are usually easier to undo.
If they are not corroded they will still need a good soak in something that'll penetrate, diesel is good. Then they may need heat. Once the head is off you will see the extent of the problem. Sometimes to blockage is made of softish crumbling stuff, sometimes it's like concrete. Either way you will have fun - possible for hours - chipping it all away.
Descaler doesn't do the job, nor penetrating oil. It's a combination of rust and mud; baked by the overheating.
In my experience it's Silver Centuries that are the worst culprits for cracking their blocks - is that what you mean? (There was no 107cc - but all the larger ones are 102cc.) It was to do with thin walls as much as anything else.
If you siezed it have a good look at the bore.
Once you have your block cleaned up you can use the old head gasket once annealed if it's not too damaged, but new ones are available from John on the main S.O.S. site, you can get a con rod from him too. I don't know about postage.
Let us know how you get on