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
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?
odd needles look very similar to the dyno jet ones in this image -
(http://s93420228.onlinehome.us/fzr/carbs/DSCF0266.JPG)
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
http://www.fjowners.com/index.php?topic=4281.30 (http://www.fjowners.com/index.php?topic=4281.30)
This is page 3 but it might help?
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
Quote from: racerrad8 on December 06, 2013, 10:47:35 AM
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 (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. :dash2:
Quote from: movenon on December 06, 2013, 10:40:47 AM
http://www.fjowners.com/index.php?topic=4281.30 (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.
Sounds like you are in good hands with Randy. :good2: :good2:
George
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 (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! :dash2:
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 (http://www.fjcatalogue.com/catalog/item/7214426/7422355.htm) "plus bigger main jets." my arse! :diablo:
so would any one like to recommend me a some jet sizes which will work well with a race exhaust and pod filters please :good2:
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. :good2:
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 (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 (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.
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 :P I wonder if they're standard sizes but from a knockoff manufacturer who puts a different marking on them.
Quote from: yampug on December 06, 2013, 02:20:11 PM
...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
jets look identical to this but with 125 -
(http://staging.british-customs.com/media/catalog/product/cache/1/image/450x450/9df78eab33525d08d6e5fb8d27136e95/m/a/main_jet_1.jpg) 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.
Quote from: andyb on December 06, 2013, 03:16:28 PM
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.
see how i get on with what i've got then i may enquire with randy what he'd recommend.(or i might have got it sussed and know what jet to ask for by then :) )
Quote from: andyb on December 06, 2013, 03:16:28 PM
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...
this is what i'm aiming to do but didn't want to start until i understood what it was i was aiming for, last couple of evening i've been reading how mikuni carbs work trying to understand what each jet does and when it comes into play. interesting reading now i've just got to spend the time setting it up.
initially i went for the easy route buy a kit and bung the bits in didn't really have a clue what it did but it looked shiny.
one other question for you lot does it make a difference that i live in the uk with what jets i'd fit? i notice earlier 3000feet mentioned i assume that means 3000 feet above sea level in relation to atmospheric pressure?
Hopefully you're reading the carb info in the FILES section. Lots of good FJ specific carb info.
You seem to be wrapped up in main jet selection. If you read the carb files, you'll find that idle circuit jetting and the needle position are far more important to a majority of riding conditions.
Quote from: FJ_Hooligan on December 06, 2013, 04:18:43 PM
Hopefully you're reading the carb info in the FILES section. Lots of good FJ specific carb info.
You seem to be wrapped up in main jet selection. If you read the carb files, you'll find that idle circuit jetting and the needle position are far more important to a majority of riding conditions.
yep been reading a lot of good stuff from there.
made a quick sketch while i was reading stuff using bits i'd found on various pages to help me understand which bit did what.
(http://i113.photobucket.com/albums/n219/yampug/fudge/carbdiagram_zpsc4948411.png)
what i found strange is different people were using different names the same bits just to confuse me even more.
any one on here ever change the main air jet when doing work on their carbs? part of the ledar air corrector jet kit was a replacement jet for this which i fitted you had to drill out the old jet cut a new thread then screw the new jet in.
does the main air jet only get used at full throttle same as main fuel jet?
not the one with the arrow the other one -
(http://www.yamahatriples.com/files/2613/3742/6737/pilot_air_jet.jpg)
picture of my carb with jet fitted
(http://i113.photobucket.com/albums/n219/yampug/fudge/DSC00616.jpg)
That is the fixed #30 "starter jet" for the "choke" circuit according to the GYSM. It does nothing when the choke is not in use.
I have always been baffled by the carb kit sellers that have you change that jet.
What size jet did you install?
Randy - RPM
Quote from: racerrad8 on December 06, 2013, 05:11:38 PM
That is the fixed #30 "starter jet" for the "choke" circuit according to the GYSM. It does nothing when the choke is not in use.
I have always been baffled by the carb kit sellers that have you change that jet.
What size jet did you install?
Randy - RPM
i'm not sure what size the jet it was as it didn't say in the instructions, is there a way to measure jet sizes?
what amused me about the kit when i was fitting it was that i asked on the uk fj owners forum if others had fitted this jet and how they'd gone about it. the response i got was that they'd fitted it infront of the original pilot air jet? i asked what would be the point of placing a larger jet infront of a smaller jet but no one seemed to know. i drilled my old jet out and fitted this new one instead.
something tells me this ledar air corrector jet kit wasn't worth the money. http://www.fjcatalogue.com/catalog/item/7214426/7422355.htm (http://www.fjcatalogue.com/catalog/item/7214426/7422355.htm)
unfortunately i hadn't heard of rpm at that time. :sorry:
Quote from: yampug on December 06, 2013, 04:35:50 PM
what i found strange is different people were using different names the same bits just to confuse me even more.
Like the people who call hoses 'pipes', or those who call gasoline 'petrol'?!?!?!?!
:lol:
Quote from: andyb on December 07, 2013, 08:03:08 AM
Like the people who call hoses 'pipes', or those who call gasoline 'petrol'?!?!?!?!
:lol:
Petrol pipes and gas hoses... Or gas pipes and petrol hoses.... I am willing to bet they also drive on drive on the wrong side of the road... Maybe Klavdy will chime in because he discovered they also wear ass-less chaps... Or are a part of some secrete Power Ranger society...
amazing how much hassle our little tiny island can cause the rest of the world. :good2:
some more-
trunk/boot
bonnet/hood
trainers/sneakers
belly pan/ think i heard some one call it a chin spoiler on here?
been checking/adjusting shims today only two were out one inlet and one exhaust. shims ordered, new plugs to go in then carb balance.
plus an oil/filter change.
roll on the summer :yahoo:
Quote from: yampug on December 07, 2013, 10:34:36 AM
been checking/adjusting shims today only two were out one inlet and one exhaust. shims ordered, new plugs to go in then carb balance.
plus an oil/filter change.
roll on the summer :yahoo:
You have the spirit of it..
Sleeping police man = speed bump
ToLet = To Rent
Tube = Subway
Quote from: racerrad8 on December 06, 2013, 05:11:38 PM
That is the fixed #30 "starter jet" for the "choke" circuit according to the GYSM. It does nothing when the choke is not in use.
Randy,
I don't think that's the correct description. That orifice leads directly into the needle jet. I've seen it called a main air bleed by Kevin Cameron. He said it is important when at WOT. It bleeds air into the main circuit to keep that circuit from swamping the intake with too much fuel (hopefully I described that right, can't find my copy of the book).
Wouldn't the starter jet be in the float bowl since that's where the choke draws its fuel from?
Quote from: FJ_Hooligan on December 07, 2013, 11:07:37 AM
Randy,
I don't think that's the correct description. That orifice leads directly into the needle jet. I've seen it called a main air bleed by Kevin Cameron. He said it is important when at WOT. It bleeds air into the main circuit to keep that circuit from swamping the intake with too much fuel (hopefully I described that right, can't find my copy of the book).
You are correct, I got myself crossed up when I was typing...the air bleed for the choke circuit is the four small hoses not that jet. :wacko3:
That jet is what I have been explained to be more of a vent. What it does is allows the fuel level around the emulsion tube to fill higher level than the float bowl level to allow complete distribution of fuel to the holes in the side of the emulsion tube. I am not sure how changing that jet size will affect the circuit as I have never done that. :unknown:
Randy - RPM
stuck waiting now till my two new shims turn up.
any one ever tried down sizing a shim on a diamond stone before?
Quote from: yampug on December 07, 2013, 01:46:13 PM
stuck waiting now till my two new shims turn up.
any one ever tried down sizing a shim on a diamond stone before?
If they are case hardened then you will be in for a rude surprise. If case hardened, only the surface will be hard, and the center soft, and you will have shims that hollow out quickly. If they are hard all the way through (100%) then you can grind and polish them till they are too thin to use... If you grind them down. let us know how they work...
Quote from: FJmonkey on December 07, 2013, 04:23:43 PM
Quote from: yampug on December 07, 2013, 01:46:13 PM
stuck waiting now till my two new shims turn up.
any one ever tried down sizing a shim on a diamond stone before?
If they are case hardened then you will be in for a rude surprise. If case hardened, only the surface will be hard, and the center soft, and you will have shims that hollow out quickly. If they are hard all the way through (100%) then you can grind and polish them till they are too thin to use... If you grind them down. let us know how they work...
good point, i shall wait for my shims to arrive. :good2: