Aftermarket Main jets

[headsbikesmopars]

Opened the carbs on my 1985 GS1150 and find some of the main jets are stamped RD and others CIR . Not regular mikuni marking stamps and not familiar with these. Mikuni has a square inside of a square stamped on the head of their jets. Just wanting to know if anyone has used these jets and if they can be trusted to meter accurately . Thanks for any insight you can lend.

Terry

[sharpy]

Personally i wouldnt, but i also never heard of those ones you said

[rapidray]

Terry, the numbers on Dynojet mains and others vary. It doesn't matter (as you know) what the # is if the hole is the size it wants and it works. This is one of the reasons I only buy STRICTLY Mikuni jets, from Sudco.
Ray.

[TxGSrider]

Ive seen the RD ones before they are an aftermarket. I try to always use the genuine Mikuni or Keihin (depending on what carbs Im working on) as Ive heard stories of the aftermarket ones not metering accurately.

[Steve]

Like Ray mentioned, it's the actual hole size that matters. Not everyone labels that size hole the same way, and not everyone is as careful to ensure that it's the proper size hole for that label.

At the very least, I would at least ensure that all four jets are from the same manufacturer.

Another thing to be aware of is that some "mechanics" will drill out the jets instead of getting the proper ones. When they do that, you will be wondering how your 120 jets are running rich when you have pods and a pipe.

.