It is just a production variation thingThis is a follow up to my post. I was unable to get the carburetor replacement for the Nikki OE4215. The vendor sent me the wrong carburetor, so I decided to replace my dropped out jets, using new o rings. As it turns out, the starter was also weak, so I replaced the starter. The engine fired right up with the new starter and o rings. No smoke. My question now is: which engine manufacturers use these same type of jets, in guess all in Nikki carburetors, held in by rubber o rings? It seems a set up for failure.
No 2 parts are ever identical so on some the holes for the jets will be a tiny fraction bigger , and we are talking microns here not thou
Put them together with a O ring that is a couple of micron smaller and you have falling jets .
Some can get pushed back with a slight smeer of rubber grease and light finger pressure
Others need silicon spray and a tap with a punch .
Not all that long ago parts would be matched up according to how far away from the perfect dimension they were but production control has got to the point that 99.99% will interchange just fine .
Back in the old days finding parts that fit perfectly together was a common occurance and was called blueprinting .
Now days it is only done on race engines & aircraft and possibily some military equipment where a cheap selling price is not the driving criteria .
In sound engineering practice every O ring that is removed gets replaced ever time it comes out .
Just like Hammer I buy rings in packets of 200 , usually in a higher grade rubber than the original and replace them as a matter of course
It take about 5 seconds to swap an O ring and cost less than 10¢ it take 30 minutes to remove strip & replace the carb so it is a no brainer