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Source for Nikki main jet, and do I use the washer?
Broke one of the main jets inside the float bowl and need to replace it. Below is a pic of it's unbroken brother. Where do I source this jet? (its engraved 160). All the leads I find online show jets with a much smaller shoulder where the head of the jet would tighten down against its crush washer or gasket.
And... the OEM jet had a silver aluminum crush washer. The Atkins rebuild kit came with a gasket-like washer that is more like treated cardboard. Use the Atkins gasket style one or source a new aluminum crush washer from McMasters?
I have questions in via email with Atkins, Mazdatrix and Rotary Response but know from searching around that often you guys have more nuanced answers than the suppliers eg use the OEM needle and seat even if the rebuild kits comes with replacements. Or maybe one of you guys as a jet and washer I can buy?
Thanks! This is the unbroken brother to the main jet I broke. Note the larger head providing a shoulder for the crush washer / gasket.
Mazdatrix.com lists a main jet for a Nikki with the SKU of 73801.160. When I Google that SKU I get a much different looking jet like this one.
I have used the jets available from Mazdatrix for years that look just like the "pierce manifolds" one that you show. Never had any issues. They might flow slightly differently than the stock ones for the same size, due to slightly different inlet configuration. If you are concerned, buy two. One for each side. I mostly use the gasket, but not always.
I have used the jets available from Mazdatrix for years that look just like the "pierce manifolds" one that you show. Never had any issues. They might flow slightly differently than the stock ones for the same size, due to slightly different inlet configuration. If you are concerned, buy two. One for each side. I mostly use the gasket, but not always.
Carl
Thanks Carl. Two ordered from Mazdatrix. Most likely I am overthinking the task... just feeling a little gun shy having missed a main seal on my engine rebuild!
And just heard back from Mazdatrix. They confirm that although they are a slightly different design in the shape of the screw head, they work just the same as the OEM.
I don't have the jets in front of me, but if I remember correctly the stock jets have a bit of a taper on the inlet whereas the Mazdatrix replacements are more straight. The taper should result in slightly more fuel flow for the same size orifice, but as I said I have not had any issues with the ones available from Mazdatrix.
Regarding the crush washers, I by far prefer the metal ones over the paper/cardboard. Rebuild kits usually come with new washers even though the originals rarely need replacement. Your idea of looking at McMaster Carr is a good idea for finding individual replacements.
For future reference you can buy the factory style main jets from anywhere that sells Hitachi main/pilot jets. The main and pilot are the same exact jet, just with a different orifice size range (108-140, and 38-43). The Hitachi jets that I've seen only go up to 140 so you'd need to drill them to 160 for the secondaries, but otherwise they are the ideal solution. Holley jets also work, although technically aren't the right thread and (supposedly) are machined inferiorly.
The no. 2 air bleed jets are also commonly available, in this case as Mikuni air jets. B42/55 is the jet type you're looking for there.
I generally buy my jets from Jets-R-Us, although I've gotten them through eBay and mower places too.
