OS46 AX problem

[Nigel R]

Andy I agree they're excellent. I fitted one to an sf and one to an rf.

[Engine Doctor]

8 hours ago, alan p said:

Regarding the plating stripping is it viable to get the liner cleaned up and replated with hard chrome, assuming you would have to hone to suit your piston if it is serviceable?

Not reallyas its a specialist process to deposit an even coating around thr brass cylinder and then hone it to the required taper. Its a type of Nickel plating thathat OS use called Nickosil. The cost of replacement is also very expensive compared to a replacement eng8be like a Force 46.

You could try getting new parts via RC Japan. They offer an excellent service at affordable prices for  genuine OS parts for current and some okder models.

Edited May 5, 2023 by Engine Doctor

[Caveman]

Alan, from the photos you've posted there doesn't appear to be any problem with your cylinder and piston.

 

This is a photo of my mine, from a MkIV Irvine 46 (manufactured by OS) and you can clearly see what's wrong. Even so the engine still ran, but badly, and it didn't throw props. Therefore, before you spend money on a new cylinder and piston do be sure that's where the problem lies.

 

 

 

From the photos you've posted your engine looks to be in excellent condition which suggested the problem lies elsewhere. I hope you get it sorted.

 

GDB

[Andy Stephenson]

What I would like to know is why OS make such a mess of NIckosil when Laser engines use the same process and their liners never strip.

Are we sure OS actually use Nickosil or is it just plain nickel.

[Martin Harris - Moderator]

Wasn't the switch from hard chroming to nickel plating to do with "environmental concerns"?  I believe Nikasil as used by Laser is a process which deposits the nickel plating directly to the aluminium with hard silicon carbide particles incorporated whereas OS simply nickel plate their brass liners to produce ABN engines.

[Nigel R]

I read somewhere that the manufacturing process is far less tolerant of contaminants, compared to hard chrome. Thus the first batch made with new chemicals was OK but by the time os had tried to squeeze a bunch more liners from the same chemicals... not so successful...

 

In not a chemist so take it with a pinch of salt. 

[Jon H]

5 hours ago, Martin Harris - Moderator said:

Wasn't the switch from hard chroming to nickel plating to do with "environmental concerns"?  I believe Nikasil as used by Laser is a process which deposits the nickel plating directly to the aluminium with hard silicon carbide particles incorporated whereas OS simply nickel plate their brass liners to produce ABN engines.

 

I also was under the impression that environmental concerns were a part of the switch from chrome. I am not exactly sure what the difference is between the OS and Laser process (we dont plate the liners, we get a specialist company to do it) but i know the plating is very thick compared to the OS. In the rare occasions they chip during finning (we add the fins after the blanks are plated) its clear how thick the plating actually is.

[Engine Doctor]

8 hours ago, Andy Stephenson said:

What I would like to know is why OS make such a mess of NIckosil when Laser engines use the same process and their liners never strip.

Are we sure OS actually use Nickosil or is it just plain nickel.

When the problem with OS first appeared ,mainly on the OS 32 SX a forumite ,I think it may have been on this forum said that he had the parts looked at by a scientist friend. Apparrently he found contamination under the plating in the form of finger prints. This also tied in to when OS had the production of these parts moved from Japan to Tiawan in the interest of the environment and a way to lower production costs ?

Nimbyism is alive and well all around the world not just the UK.

It was  also  the time that OS introduced a cheaper range of engines like the LA and a couple of cheaper four strokes; not much cheaper to buy but certainly cheaper in quality and materials and inferior to the models they replaced.

Like so many companies that were once world leaders OS has become just another manufacturer undermind by cheap Chinese goods like ASP etc aided and abetted no doubt by bean counters as were the British motor and motorcycle industries.

Thankfully we still have Laser engines to call our own and be proud of ... for now anyway.