Rejetting after aYoshimura 4into one on my 84

[charleygofast]

Im going to install a Yoshimura 4into1 exhaust on my 84FJ. Does anyone have any jetting suggestions? The only other modifications are Dynatek 3ohm coils, and a k/n air filter in the stock air box. The exhaust is about 15 years old and has an aluminum can. It looks similiar to the one on the bike in Reds profile pic. Thanks! Charley

[Pat Conlon]

A common question Charley.
For a start, did you read this? http://www.fjowners.com/index.php?topic=1974.0

If you stay with Mikuni parts (as opposed to DynoJet parts)  I would suggest #40 pilot jets and 115 mains with a shim on the needles.

Then, Read your plugs.

At the very least bump up the pilot jets.
The #37.5 stock pilot jets were lean the day the FJ left the factory.

[charleygofast]

Thanks Pat! That made my day! I cant wait to get home tonight and tear into it. Then tomorrow its road test time. Buy the way, beautiful bike Pat!                 Cheers to you! Charley       

[Pat Conlon]

Thanks Charley...'84's rule.

When you get into your carbs and find yourself fighting with your stock airbox, consider replacing the airbox with this:


These filter much better than the traditional paper K&N pod filters and make removal/replacing the carbs a snap.
http://www.rpmracingca.com/proddetail.asp?prod=Carb%3ARPMPod&cat=39

Also consider this nifty kit from RPM. Replace all those soft JIS phillips head screws with ss allens... and while your carbs are apart, pull your float needle seats and replace the o rings, also included in the kit. You cant beat the $22 price.

http://www.rpmracingca.com/proddetail.asp?prod=carbkit&cat=24

[Alf]

Don´t miss to fit new emulsion tubes. The OE ones must be completely oval by now and this enrichen the mixture affecting performance
Randy has an excellent complete carb rebuild kit too

[andyb]

Also consider this nifty kit from RPM. Replace all those soft JIS phillips head screws with ss allens... and while your carbs are apart, pull your float needle seats and replace the o rings, also included in the kit. You cant beat the $22 price.

http://www.rpmracingca.com/proddetail.asp?prod=carbkit&cat=24

Best money you can put into your FJ.  Full stop.

[FJ_Hooligan]

And that picture is only showing half of the total kit.  There are a LOT more SS screws in that kit!

[simi_ed]

Also consider this nifty kit from RPM. Replace all those soft JIS phillips head screws with ss allens... and while your carbs are apart, pull your float needle seats and replace the o rings, also included in the kit. You cant beat the $22 price.

http://www.rpmracingca.com/proddetail.asp?prod=carbkit&cat=24

Best money you can put into your FJ.  Full stop.

+1

[charleygofast]

I have the 115 main jets and the #40 pilots. I do have a set of K/N pods. Maybe this is a good time to put those on. Will I need to bump up those jets a bit more or will these be okay?                                                                                                                                                                                       Thanks for your help everyone!                                                                                                                                                                              Charley

[Pat Conlon]

Throw those K&N pods away....poor, poor filtering. Your engine will thank you.

Stay with your oem airbox until you can get some foam UniPods.

Start with the 40/115 combo, and needle shim.....

[Woodsman]

Same exhaust was on mine when i got it but it was in bad shape. I sourced a full Motad from a breakers and noticed no difference (except sound) when i swapped them over. The traditional layout allowed access to the sump plug which meant not having to drain from the oil cooler line.
Sean.

[charleygofast]

Dam! Well at least I didnt have to pay the $200. the K/Ns retail for. These were on the 1280 motor I have and hooked up to 39mm flat slide mics. I will be ordering the foam UNIs, meanwhile the pipe goes on and I rejet and ride! Looks like its going to be a nice day for it.                                                                      Watch everything and enjoy the piss out of it!                                                                                                                                                                                                                                                                                                                                                                        Charley

[charleygofast]

Hello all. I put on the Yoshi. pipe and shes now sounding the way I hoped she would. I didnt get to road test her yet, but around the driveway it felt pretty nice and has that bark of authority I was looking for. Thanks everyone for your input on this mod. especially you Pat!  I put a pic in the gallery but am still unsure how to include pictures in  posts. Im still learning about computers and FJs.  Have a great day everyone, and if you can, get out and ride today! Thanks again!                                                                                                                                 Charley                               
                                                               

[Pat Conlon]

Glad to help Scott....just passing on what the members here have taught me.

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