Hi comp. inserts what kind ??

The little "skirt" on the insice cylinder portion of them makes them look like they could be MP Jet glow plugs. No way to know without dimensions.

Better pics nelson 15 I another bag that came in the lot and some alum. conn. rods The Cox .049 is just reference I don't have a MP Jet . Eric

So, I still think it is for the Rossi .15 or possibly the Cox Conquest, the Rossi one should fit in both.

I can live with that Thank You!! That way I know if need to keep them or move them along , I have no Rossi Sooo ! Eric

To be more certain, you can measure the diameter of the lowest part that goes into the cylinder. It will be very close to the bore diameter of the cylinder.

If they turn out to be MP Jet .061 plugs, I would like a couple of them. I'll take a look at what mine look like tomorrow.
Rusty

Conquest  
Top diameter: 13 mm
bottom diameter: 14,9 mm
edge thickness: 1,85 mm
 My measurements are
top 0.54 = 13.716 mm                                                                                                                                             bott.  0.574= 14.5746 mm                                                                                                                                        thick  0.056 = 1.4224 mm                                                                                                                                         so that's pretty close with my HF micrometer // If not Conquest would be .15 size engine ?? I for got to as Thank You Lieven for taking your time to measure that hd. for me , Eric

Several Russian engines use those Rossi style plugs as well. Ken

Yes, certainly, there is the Uctkam and MDS etc. too, but the electrode is a little different on those as I remember it.