I've just stripped the carbs for the first time on a bike I bought, and I think the needles mighy not be standard. In the carb setup guide it says that there are different needles for front and rear with a code on them (J51A and J51B), but hese needles have no numbers or letters anywhere on them that I can see and I was just wondering if anybody could identify them, or if they are factory needles tell me how to identify which are the A needles and which are the B.

nothing stamped on the head ?

The original needles are silver in colour and all the aftermarket ones I have seen have adjustable clip position for needle height, so no idea what these are from I'm afraid.

Suzuki416 wrote: ↑

Wed May 08, 2019 12:27 pm

nothing stamped on the head ?

Nope nothing stamped on them anywhere.

gavins wrote: ↑

Wed May 08, 2019 12:31 pm

The original needles are silver in colour and all the aftermarket ones I have seen have adjustable clip position for needle height, so no idea what these are from I'm afraid.

Yeah I had a bit of a search but couldn't find any like them. They're also all identical in length, whereas the factory ones were slightly longer in the front.

So the previous owner has told me that these are the Rick Oliver road needles.

Does anyone have a setup guide for ricks kit that they wouldn't mind sharing? The needles in my carbs have a .5mm washer underneath, is this normal for Ricks needles?
If they don't need the washer it would explain a few of the weird rich conditions I'm getting at lower RPM.

One 0.5mm shim is normal. Best person to ask about setup would be Rick himself, you can find his contact details on his stocklist here.

Good news, I contacted Rick and he recommended I remove the shims and see that goes. It's now smooth as butter through the previously problematic 3 - 7k rev range, but still has a slight hiccup at 3kRPM (very slight) and is sooting up the left rear plug a little. That particular needle looked a little more worn than the rest, so I think it's still just a teeny bit rich on that cylinder at that particular needle position (where it sits at 3k rpm).
Will look at replacing the needles in the near future, which should (with a balance) sort out the low RPM running once and for all.

Isn't it nice when the thing you think is causing the problem, is indeed causing the problem?

I've not tried Rick's needles but in my experience standard needles shimmed up an extra 0.5mm (so 1mm in total) and the slide holes drilled out to 2.5mm gives the best results, for the UK's climate anyway. I've tried Dynojet and Factory Pro needles and both were rubbish compared to the stock needles. Check your float heights are set correctly as well.