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carb jet kit

Started by bigbore2, March 06, 2012, 03:30:04 PM

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bigbore2

Hey everyone-  84 FJ1100-----Rebuilding/cleaning my carbs. What do you guys recommend for a carb kit.
Dynojet, FactoryPro or something else. Or just buy the parts individually.

andyb

Doing anything else while you're there?  Pipe?  Filters?  Etc?

Mind fiddling a bit and having the carbs off and on a few times?  (In reality, that's likely no matter if you go with a kit or not.)

Here is a couple of baseline setups for various configurations.  However, do notice that a DJ or OEM needle will need a much smaller jet than a FP will on the mains.  A 122 main is the usual starting point for a piped and pod-equipped bike using the stock needles, but a FP needle will mean you'll want to start up in the low 130 range.

bigbore2

thanx for the replies.  84 1100 has 4 into 1 pipe with a Yosh muffler and a K&N air filter in the stock airbox. After thinking about it, I am leaning toward my local bike shop guy to set up the tuning.
Altitude is 5000 ft. here.  These are popular engines with the local mini-car racing at the track, so he has experience tuning these engines.
Do i get an advantage using Factory Pro or Dynajet parts over stock?  The needle profile is the same as stock or better?   I know they have clip positions cut into the needle tops and stock needles have to be shimmed for tuning.

weymouth399

You will get alot of different answers on who's kit to use. It is a touchy thing. I use HSR kits he has his own needle design. I have had a few different kinds in my race cars over the years and his respond the best. Now that said I don't think many of us could feel that difference on a bike. I know I wouldn't/couldn't.
It just needs to be close for riding.
This is what most FJ's in this area Maine Sea level to 6000 ft (mine runs good).
PJ 40 or a drilled out 37.5
MJ 110-117.5 depending on needle setup.
AJ 155    160 if 42.5 PJ
Needle on 3rd clip if adj. If stk no shims
AS 2.5-3.5 turns out

Bob W
84 FJ 1100
86 FJ1200
89 FJ1200
5  FJ POWERED race cars
76 LB80 Chappy
93 KX500 ice for sale
00 KX500 ice/dirt
04 KDX220 dirt for sale
04 KX500 ice
08 KLX450 ice/road
72 CT90x2 for sale

racerrad8

Quote from: bigbore2 on March 07, 2012, 02:27:47 PM
Do i get an advantage using Factory Pro or Dynajet parts over stock? 

Like Bob said, carbs are always a debate of "who's" tuner kit is better...

I can tell you that I have had great success with both the race cars and bikes using all stock parts. No drilling required and no funky numbered aftermarket jets that require the use of a conversion chart to calculate from the stock Mikuni sizes.

I do not sell any one manufactures tuner kit, the kits I offer have replacement stock parts in them. I have a wide variety of stock jets in the ranges required to get you dialed in.

I have all of the stock parts in stock that can get your carbs in the ballpark and with some minor tuning with those stock parts you will be good to go.

Now remember the 1100 used the flat bottom slide, so the 1200 emulsion tubes will not work in those carbs. Everything else if the same with the exclusion of the slide & tube. The 1100 kit I have in stock has the correct emulsion tubes.

Randy - RPM

Randy - RPM

SlowOldGuy

 Randy,
Only the '84 carbs had the flat bottom slides and unshrouded emulsion tubes.  The '85 carbs are identical to the rest of the FJ models.

DavidR.

bigbore2

Ok, thanx for all the info.  I am going to go with stock parts and see how that turns out. I can get started AS SOON as the snow stops flying. And the sun comes out. And the birds start singing. And the bugs start bugging. And...

neo297

I had a question for those who are using the uni filters are they more restrictive than the K&N's or V&H cloth filters it seems the mains being used are way small. I have vance and hines pods, supertrapp 4 into 1 NO discs, dj needles 2nd groove from the top but I needed dj144 mains the 122, 124 132 were too lean it popped and burbuled and would not run under load spark plug chop test no fouling at all, with the 144's and mixture screws at 2 3/4 turns out it idles smooth pulls like a truck no flat spots or stumbles roll on top gear pulls from 2500 rpm to red line no let up it does pop when throttle is closed so I may need to go up to 40 on the pilot jets  (37.5 in now) it just seemed i had to use much bigger mains than I was seeing others report on this thread maybe my pipe and pods is just that less restrictive.
Paul
'84 Fj1100
'86 Fj1200
'85 Fj600(sold)
'86 Fz600(sold)
'87 Fz750(given to friend)

racerrad8

Quote from: neo297 on March 13, 2012, 01:40:03 PM
I had a question for those who are using the uni filters are they more restrictive than the K&N's or V&H cloth filters it seems the mains being used are way small.

There is no difference in flow, only better filtering.

Quote from: neo297 on March 13, 2012, 01:40:03 PM
...but I needed dj144 mains the 122, 124 132 were too lean...

I think you are comparing apples to oranges. You cannot compare the DJ jets sizes to Mikuni sizes, they are not numbered the same. Since Mikuni never made 122, 124 or 132, you must be referring to DJ jets.

Mikuni sizes are 120, 122.5, 125, 127.5, 130 etc.

DynoJet jets are marked according to the diameter of the hole in the jet' ie: DJ150 = 1.5mm and DJ175 = 1.75mm.

This is not true for Mikuni or most other OEM equivalent jets. This size Mikuni jet, 122.5 is marked according to its' flow rate: ie: 122.5 = a rating of 122.5 cc of fuel per minute.

Here is a chart listed with a conversion chart for the DJ to Mikuni sizes.

Jet Conversion Chart

Randy - RPM

Randy - RPM

fj1289

Don 't forget too that the needle you use has a big effect on the main jet size. 

For example, although FactoryPro jet kits use mikuni jets, the FactoryPro needles are fatter than Yamaha needles and require a much larger main jet than would be right for the Yamaha needles.   

neo297

Thanks, that chart is awsome I printed it to keep in my FJ files. I did not mean to sound like I was comparing the sizes as if they were the same for each brand just that I just saw the mikuni #'s to be in the 115 -120 range with 1 at 130 so that would have made DJ sizes in the 120-130 range and for me here near Dallas the 120 through mid 130's dj mains were too small I was using the dj needle that came in the kit ( I bought it years ago when I had rejetted my cv carbs before going to the keihins). I did not realize the FP jets were the mikuni's
Paul
'84 Fj1100
'86 Fj1200
'85 Fj600(sold)
'86 Fz600(sold)
'87 Fz750(given to friend)