Installing HRC carb kit

[doodleface]

Hey guys, my carb kit arrived today, and it comes with several colour coded needles. i've asked rick oliver what thats about, what colours to start with and where to put the needle clips etc, but always interested to hear from everyone. As I go through I'll take some photo's. I have 4 days off, I'm hell bored. :)

[lukemillar]

The needle colour shows the difference sizes - Rick supplies 2: 8ZF and 8ZG. If i remember correctly the higher the last letter is in the alphabet, the leaner the needle. As for which is which, I thought he supplies them stuck in a piece of cardboard with the size written on the side?

Clip position, I didn't think these needles were adjustable? At least, mine aren't.

Base setup- Dyno time is the best way to get it bang on. However, the last setup I ran on a stock engine was as follows:-

8ZG needles with no washers
142.5 front, 145 rear
HRC emulsion tubes
NC24 slides
Drilled bracket with fins removed
Fibre glass air scoop
short velocity stacks
pilot screws 2 turns

which worked pretty well.

Hope that helps

Thanks
Luke

[Drunkn Munky]

Luke I belive doodleface has rvf carbs not vfr

[lukemillar]

Doh! Sorry - I just assumed.

In that case, I have no idea!

[doodleface]

You are correct Drunk Monkey, I do have an RVF. Looks Like i have 3 sets of needles here. There is also a set of springs not shown.
The kit doesn't come with jets so I either have 115's or 150's I can use.
Needle sizes are :
J9MA :RED
J9MB: BLUE
J9MC: GREEN

[doodleface]

1: I'm running with the 115's initially.
2: Im not drilling the slides... yet... seems dangerous. Some people do, some don't. I wont yet.
3: Depending on how the dyno graph looks with the 115's I'll change to a 122.5 front and 125 rear next. I'll buy some 117.5s too just in case.
4: Needle clips, my most contentious issue. Will use the B (for blue) lowest setting with shim. I believe, that it is what is intended, otherwise why would there be a shim to raise it even more? Makes no sence. So B it is, shimmed.
5: Your mum said hi.

[Cammo]

Main jet size is mostly determined on these bikes by what filter and airbox setup you're using. What are you running?

If you're installing all of the hrc carb parts it's best to run no filter and the hrc type airbox upper (will run very rich if you use a filter): viewtopic.php?f=24&t=36303

With this type of setup you'd be looking at about 150 size main jets. Follow the hrc manual and you won't go far wrong: http://www.400greybike.com/docs.htm

For a track bike, I find that needle type/setting is the least most important part of the carb setup. Just choose a starting point, try it out, change needle type or setting and then see how it feels etc.

Don't drill the slides, no need.

[doodleface]

Cammo I tried to understand all that jap, lol... i failed.
Also I removed the fuel filter cause i generally don't run them, but I have been told the fuel tap modification is bogus and is not required... I never know what to believe with that stuff Anyway.

I'm running no filter at all, And I quickly made this airbox with the existing parts. I cut the the hole bigger in the front to accomodate the bottom of the old inlet, cut it open (keeping some of the verticals to keep it somewhat rigid) then just used some fuel safe silicone to glue it in. Looks ok, front hole could be bigger though. When I get some more time I'll make a nice one like Tyga's. I'll round the bottom edge of this one now though.

So, I went with the blue middle sized ones shimmed to 1mm.
I also put in the 115's simply because it seemed on the dyno to run rich as shit.
I can always go back up on the jet sizes. heres some pics.

So, all put back together now with:

115 sized jets
new springs (Shorter but stiffer then origninal)
blue (mid range) sized needles shimmed to 1mm
RVF airbox mod.
- For this it's slightly reminiscant of the tyga one. My front hole is now bigger so it maintains the natural size of 85mmx54mm (From memory I'm upstairs atm.) even with this doohicky. (Tongue)

The nice thing about this is I can always go larger, or always go smaller, and when i actually get some time I'll make a nice fiberglass one, but for now I can take this off to a dyno and see where I'm at on the lean/rich scale.

[Drunkn Munky]

That is going to run mega lean with 115's

[Cammo]

That is going to run mega lean with 115's

True that! 150's will be very close to the mark, dont waste your time with 115's.

The airbox looks good, should work well with the carb kit (and proper sized jets!).

You will need to HRC mod the fuel tap. The big jets can/will run the carbs dry with the standard tap. Fit a dry break fuel line connector and there's no big issues. Having another fuel filter will compound the issue so good one removing it.