idle issues as well -

[moparman70]

I pulled out my 90 and the usual reliable everything would not idle --- it is not the same symptom as an earlier post but similar ---

Note - ran fine last time out but there has been about 2 months since that occurred.   Start up is fine - and with full choke warms normal -- and above 3 k seems fine -- when I take the choke off -- no idle -- if I try and run and little choke -- it will surge.   On the rode I can feel it wanting to die when I release the throttle and if I do come to a stop it will.

Found this -- from the earlier post --- just wondering if you think the same thing.  I am not a carb person I read through AndyB help guide and it seems very complicated or at the very  least a lot that can go wrong when you assemble.   Looking for the quick fix as so close to rally but know they may need overhaul.

Anyways let me know what you think

from "idle issues" April 13



Quote from: FJ_Hooligan on April 05, 2014, 04:53:15 PM


Quote from: feederbb on April 05, 2014, 11:38:31 AM

Didn't mess with any mixture screws or idle screws etc. and didn't really see how they could change by themselves in such a dramtic way basically overnight.  


Uh, I think I found your problem.  If you didn't remove the idle mixture screws then the idle circuit is not clean.  Your description sounds exactly like dirty/clogged idle circuits.

The idle jet is tiny and dirt can enter the circuit from the air pilot jet.  A grain of sand/dirt can be a significant obstruction at the mixture screw orifice.

I agree with the above.  But before I would pull the carbs apart I would remove the fuel air screws (each screw has a O ring, washer and spring) spray some carb cleaner down each hole. Don't loose any of the O rings or washers.... Re-seat each screw and back each one out 2.5 turns. Start her up and try to get your idle at around 1150 RPM + -.  Now do a blip test. Then sync the carbs and then do another blip test for final adjustment.  Last rest your idle to 1150/1200 RPM and hopefully you are up and running.  If not then I would pull the carbs and do a deep cleaning.

Also as a test you can run your fuel air screws in one at a time. When the screw get toward the bottom you should hear the engine running rough. If you get the screw all the way in and you can't tell any difference then it's dirty inside.

In my experience take your time syncing the carbs, adjust , let the idle RPM settle and touch up as required. When you are close 1/8 of a turn makes a difference.

Your main jets are not a player in your problem as I see it.  0 to 1/4 throttle is mostly the pilot jet, fuel air screw adjustment and syncing.  Something else that can effect it over all is the float level adjustment.  There is a correct way and not so correct way to do the adjusting.  The first time I did that I chose to do it the not so correct way and had the privilege to do it over...  dash2  lol School of hard knocks.
George


 

[FJmonkey]

Steve, your FJ is simply pissed at you for letting it sit that long. With our crappy gas, you most likely have gummed up idle jets. I have had some luck with carb cleaners in the fuel but only when the problem is minor. You may have to pull the carbs and make sure they get a good cleaning. Order #40 jets from Randy, you will have new/clean jets and it seems to smooth out idle issues as well. Fuel stabilizers (Startron seems to be a favorite) help with longer storage periods. Order some UNI pods if you don't already have them, saves from having to put the air box back on.

[moparman70]

I know I know --- I am paying for the lack of use --- here is about the only thing I think I can do when it comes to the carbs -- in was part of the first post --- is this what you mean about idle screws or is it the one that you can't get to until you take it all apart

I agree with the above.  But before I would pull the carbs apart I would remove the fuel air screws (each screw has a O ring, washer and spring) spray some carb cleaner down each hole. Don't loose any of the O rings or washers.... Re-seat each screw and back each one out 2.5 turns. Start her up and try to get your idle at around 1150 RPM +

[FJmonkey]

http://www.ronayersmotorcycles.com/fiche_section_detail.asp?section=3937435&category=Motorcycles&make=Yamaha&year=1986&fveh=177129

The idle jet is #11, what you are talking about is #27. It can't hurt to pull and clean #27, before you do, turn each one closed and count the rotations. They may not be at 2.5 turns. And to reduce the variables put each on back in the same place. If that don't work then you will need to pull the bowls off and clean #11.

[moparman70]

got it -- thanks ...