G250? Worth servicing?

[buddhasummer]

Very helpful, thank you, I will do just that.

 

[buddhasummer]

I was under the impression that the service kit for the S555, S600 and G250v could be used with the older G250. Looking at schematics it looks as though the adjuster knob O ring on the G250 is not shared with the others. Is this the case? Or is it the same part but SP just changed the number? I'm talking about part number 01-050-138 specifically. Cheers.

 

[buddhasummer]

According to the schematics there is an O ring on the flow vane. However when I attempted to remove it it was more like a hard plastic (red) ring than an O ring. In fact I may well have damage the flow van surface trying to get it off. In the end the only way to remove it was to break the ring. My other G250 looks to be exactly the same. Have I done something wrong or is there a knack to getting this off? cheers.

 

[NotSure]

I was under the impression that the service kit for the S555, S600 and G250v could be used with the older G250. Looking at schematics it looks as though the adjuster knob O ring on the G250 is not shared with the others. Is this the case? Or is it the same part but SP just changed the number? I'm talking about part number 01-050-138 specifically. Cheers.

The G250V uses the same size o-ring as your G250 but the part number is 01-050-351. Most likely they changed the number when they changed material to be more O2 compatible.

 

[buddhasummer]

Thank you.

 

[NotSure]

According to the schematics there is an O ring on the flow vane. However when I attempted to remove it it was more like a hard plastic (red) ring than an O ring. In fact I may well have damage the flow van surface trying to get it off. In the end the only way to remove it was to break the ring. My other G250 looks to be exactly the same. Have I done something wrong or is there a knack to getting this off? cheers.View attachment 378894

That's just what old o-rings look like sometimes after 25 or 30 years. A few nicks most likely won't be a problem because there isn't any significant pressure difference across that o-ring. That o-ring won't come in your rebuild kit but a soft -008 works great.

 

[redacted]

Back in the colored o-ring days, the smaller red o-rings seemed to have a durability problem. Over time (a long time) they turn to plastic. You will also find that on the red orifice o-ring. Other colors and even the larger diameter red o-rings (like on a Mk2 and Mk5 yoke retainer did not have the same problem.

 

[buddhasummer]

Thank you for both the additional info. Yes, it turned to plastic. So that particular O ring (flow vane) isn't included in the SP S600,S555, G250 service kit or the kits supplied by VDH? Here in Japan buying or finding individual or even packs of O rings is very difficult, I'd hate for one O ring to hold me up. Cheers

 

[buddhasummer]

On a side note I went into one of my local LDS who do sell me parts, they said getting the parts would be difficult but I'm not sure why exactly, whether they meant SP or the parts were hard to find, however they said they would try. It seems the orifice should still be available given its the same as the G250V, ditto the spring, the O ring kits are shared by the S600, S555 it seems, the new S-wing poppet etc is still available, the vane O ring might be a problem for me. The Diaphrgam might be an issue but mine, other than being a little "wrinkly" look to be in OK shape. A couple of the tabs on the diaphragm spacer ring have snapped off but I'm assuming that shouldn't be a problem. The exhaust valves look fine. But all in all it looks like they will breathe again. Zung posted in another thread some very clear instructions on how to tune, thanks Zung.

 

[redacted]

Check but I'm prtty sure Bryan's kits include all o-rings.