searching for needle jets

[markush]

Hello everyone!
I'm searching a replacement for no longer available needle jets Mikuni series 172 for GT250A- and GT550-carburetors.
There are series 169 mentioned as suitable:
https://www.jetsrus.com/a_jets_by_carbu ... mikuni.htm
Can anyone confirm this?
Or other ideas?

[Vintageman]

I know they say that but not completely true. The 169 series shoulder is 1mm shorter than 172. So is it will set 1mm lower in carb. Some, as I tried to shim it 1mm up, be careful the air hole may not line up and be partially blocked by carb body.

So next time I would just let it set 1mm lower and raise clip on needle to next higher position (which is also 1mm) so all is well. the shroud will set a little lower but can't see that really being a significant issue given how tall it is, I have not tried this latter statement but would with no worries. What else can you do. And you get a nice fresh needle jet which is so important.

[tz375]

I have seen that comment but they are different. 169 is a Primary type that takes hex jets and has a 1.5mm flange where it sits in the bore. 172 is 1mm longer than a 169 and has a 2.5mm flange (mounting ring). I think a 172 takes round jets but I'm not 100% sure of that.

So a 169 could be used in place of a 172 but would sit slightly (1mm) low in the bore.

#182 is the same height as a 172 and has the same 2.5mm flange but is designed to take hex jets. I suspect that they will be closer than 169s.

[PaulD]

Have you tried Crusin Image? They seem to supply kits for most bikes, I've had full kits for both my GT750J and T500 and they work a treat. I even bought a set of emulsion tubes (jet tubes) for both bikes as mine where chewed up by a previous owner.

[Vintageman]

#182 is the same height as a 172 and has the same 2.5mm flange but is designed to take hex jets. I suspect that they will be closer than 169s.

If Tz375 is correct (some dimensions) the 182 is the way to go The fact it takes Hex jets versus round, well you can cross hex to round for proper flow or cross thread a round into the Hex threads. There is a paper by the respected board member that agrees with me... others don't, Oh well, works for me for years.

I tried matching a hex to round in my case there was no direct flow match... had to go higher or lower. I did both and still not correct... hmm, those jets are a very different design... put the proper mikuni round and all was as it should be. If you are modifying you bike then I suppose it won't matter where you start Hex or round.

The good news is you have options to get a nice shinny needle jet

[markush]

Hello!

The #182 I had already found at http://3cyl.com/mraxl/partid/carb/jetid/jetid.htm but you cannot be sure that informations on web pages are always error-free. That is why I asked here if anyone already has installed other needle jets.
The use of "large hex"-Jets should be no problem. There are the conversions tables "round reverse"<>"large Hex" to get a starting point.

@PaulD: He has been asked by a friend of mine about the type and size of needle jets in his repair kits:
Answer: "There is not size on the jets. So, I can't confirm how many sizes. sorry kind regards"
not very helpful

bye
Markus