carb needles?

[yampug]

i've been replacing my carb diaphrams today with a spare set i've had for a while can't remember where they came from but they were from a set of fj carbs. the spare set appear to have different length and shape needles fitted they're shorter in length and instead of going to an angled taper like the ones on randys site they just taper off.

any idea what they are from and why they would be shorter?

my carbs are a bit of a mismatch to be honest my bikes a 93 but the carbs have a twin fuel inlet i think the originals had a single inlet so i assume these are from an earlier model. not sure if the knackered diaphrams came from that set or another.

one other concern does what ever needle i have fitted need to match the needle shaft or are they all the same?

oh and what clip setting should the needles be on as standard? just incase some one has been fiddling with it before me. i've got pod filters and race cans if that makes a difference.

thanks

[yampug]

just taken one of the knackered diaphrams apart and found numbers on the side of the needle 5fz74(uk standard needles) the needles on the spare diaphrams don't have any markings on them and the clip is in position 2 from the top they also have a shim/washer between the clip and the little plastic bit.

are they needles from a dynojet kit?

[yampug]

odd needles look very similar to the dyno jet ones in this image -

[movenon]

Randy at RPM is one of the carb gurus, he might be on today. You can also PM him or email him through his WEB site and he can get you straight.
I think there is at least 2 different slides in the FJ line up compair the cut outs between your existing slides vs the ones you installed..

I kind of had the same problem on my bike when it came to the needle's and jet's, it had an aftermarket DJ (?) kit in it. I had Randy send me new jets and adjustable needles to match during the rebuild. At present I am in the middle position but I am at 3000 feet. I still have the DJ springs installed, no idea if that hurts or helps....

The shim as you stated is worth about a half step of adjustment. I think my old needles (DJ ?) were aluminum or appeared to be so. Stock ones were none adjustable in the US. Randy has the adjustable ones. There should be a washer on top of the clip also.

George

[movenon]

http://www.fjowners.com/index.php?topic=4281.30

This is page 3 but it might help?

[racerrad8]

Are the slides flat bottom or curved?

Are they all the same, old vs. new?

If you have dual feed carbs those are gravity feed as sell and if they were 1100 carbs then the carb slide will be flat bottom.

Randy - RPM

[yampug]

Are the slides flat bottom or curved?

Are they all the same, old vs. new?

If you have dual feed carbs those are gravity feed as sell and if they were 1100 carbs then the carb slide will be flat bottom.

Randy - RPM

bottoms are all curved on both sets of slides. all look the same. yes i think they were gravity fed at some point but have been rebuilt using kit for my bike(don't think randy approved of my rebuild kit selection at the time)

have had a look on google image at dyno jet needles and i think i've identified my odd shaped needles as dynojet needles. they have six slots for the clip same as dj needles.

think i'll try the needles for a while see how they feel i've set them up as per instructions on the dj site. http://www.dynojet.com/pdf/4127.pdf

no too worried now i know what i've got....one set of standard needles and one set of dj needles.

i've already got a slightly larger main jet and pilot jet fitted from a ledar air corrector kit i fitted a long time ago that came with my pod filters though i'm not sure what size they are.... the joys of playing with stuff that seems like a good idea at the time.

wish i knew where these diaphrams came from the rest of the dj kit is in those carbs.

[yampug]

http://www.fjowners.com/index.php?topic=4281.30

This is page 3 but it might help?

thanks, yes that's the one's i've got thought not quite as manky looking as those.

[movenon]

Sounds like you are in good hands with Randy. 

George

[yampug]

that was fun thought i'd check if my mixture screws were set at 3 turns out first screw undid fine others not so fine one stuck solid.

carbs back on bike now though, funny shaped dyno needles fitted to diaphrams checked main jet and it's got 125 AB stamped on it which doesn't correspond to any of the dyno jet sizes in their instructions(108,112,114,118) or mikuni sizes fitted as standard(110)

all though if it's a keihin jet then it does correspond - http://www.jetsrus.com/FAQs/FAQ_mikuni_vs_dynojet_vs_keihin_sizes.htm

and would make it exactly the same size as a standard main jet!

me thinks ledar are pulling a fast one!  google image searched keihin main jet and it's stamped same as one i've got fitted!  another con the uk fj club is flogging - http://www.fjcatalogue.com/catalog/item/7214426/7422355.htm   "plus bigger main jets." my arse!

so would any one like to recommend me a some jet sizes which will work well with a race exhaust and pod filters please

[yampug]

something else i just checked the bag which the ledar air jet kit came in and i'd put the old jets from the carbs in the bag - mikuni 112.5's so it looks like i was thinking i was putting a larger go faster main jet in and in fact i was actually changing it for a smaller main jet as the carbs came from an earlier model fj!

idiot award goes to me thanks.

[yampug]

some how it seems i now have a stage 3 dyno kit now installed! f$c% knows how i managed that

using this - http://www.jetsrus.com/FAQs/FAQ_mikuni_vs_dynojet_vs_keihin_sizes.htm  i've found i've got the equivalent of dj main jet size 118

and using the instructions for a dj stage 3 kit http://www.dynojet.com/pdf/4127.pdf i've worked out that my bike should be set up for stage 3 using dj main jet size 118 as it's got pods and a race can.

[andyb]

Dunno about the AB, but a 125 is a typical mikuni size.  If that's what it is or corresponds to, it'll be close enough to work well, though maybe on the rich side a pinch.  If it's for a Keihin and comparable to a 110, it'll probably still run, but break up on the big end.

Honestly, if you can afford the easy solution, it's the best by no small margin.  Just buy whatever Randy tells you to buy, and you'll be golden.  Probably 40 pilots, 122.5ish mains, and a set of known needles.

Otherwise, be cautious and do a number of plug chops from various rpm/throttle positions to ensure you've got things set dead on.  That sort of tuning is time consuming, but actually sort of fun, unless the cops see you winding fourth gear out to check your plugs...


Damnit Randy, posting what I was posting at the same time   I wonder if they're standard sizes but from a knockoff manufacturer who puts a different marking on them.

[racerrad8]

...and it's got 125 AB stamped on it which doesn't correspond to any of the dyno jet sizes in their instructions(108,112,114,118) or mikuni sizes fitted as standard(110)

or they could be a Mikuni jet size since they range like this; 117.5, 120, 122.5, 125, 127.5

Randy

edit...damn Andy beat me too it

[yampug]

jets look identical to this but with 125 -
which is listed as a KEIHIN jet

i'll take it steady with what i've changed and see how it runs. if it runs lean i can change over to the 112.5 mikuni main jets i've got.

i was more interested in seeing what these new needles make it run like the main jets for full throttle and to be honest i don't use that much especially not at the moment as the roads are covered in salt and crap here in the uk.

jets that are in it have been there since 2008 and it's not dead yet.