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General Category => General Discussion => What did you do to your FJ today? => Topic started by: Joe Sull on May 11, 2014, 03:59:19 PM

Title: Changed float height
Post by: Joe Sull on May 11, 2014, 03:59:19 PM
Still having problems down in the idle / part throttle area. I read this;

a bike that runs cleanly at small throttle openings when cold,
but starts to show signs of richness as it heats up to full operating
temperature, will usually be leaned out enough to be correct if the fuel
level is LOWERED 1mm.

I changed the float height from .86" ish to .89" (22.6 mm). The problem gets worse
as the bike heats up. Tomorrow I'll check it.
Title: Re: Changed float height
Post by: andyb on May 11, 2014, 05:54:25 PM
From a low rpm cruise, say 2500 revs in third, snap the gas to WOT.  If it stutters a moment and then pulls hard, keep looking at float level.  If it doesn't want to run cleanly while you're at that cruise, trying to surge and giving you a hard time holding the speed steady, look at the pilots and mixture screws... but first, just in case, check your chain.  A chain that has uneven wear feels really similiar, and is really hard to fix with carb settings!  You can screw the mix screws in a bit and see if that leans things enough, but you'll also want to make sure that the mix screws have all the pieces where they should be and aren't leaking (those tiny orings are easy to accidentally chew up if you don't get it put together right, and make the results of changing the screw settings unpredictable and nonlinear).

The very first thing I'd suggest is making sure you've got good quality fresh gas though.
Title: Re: Changed float height
Post by: Joe Sull on May 12, 2014, 07:53:06 PM
Thanks Andy. I didn't have time to take it for a ride today. I did start it and warm'm up. She started different. Before, she ran like crap after taking it off choke. It would idle just after choke but as soon as I give it some throttle, it wanted to die. I would keep the rmp's up driving and get her a little warmer then she would run OK till it got hot.
Now I can blip the throttle right after coming off choke. It definitely seemed to run better. I'll give all your suggestions a try and get back to you. My chain is good, properly adjusted and lubed. As far as gas, I got three stations to choose from but they get there gas from the same source. When I removed the carb bowls, I saw some fine grit in the bottom. I took out my idle jets and blew them out. It's possible that there was some blockage there. It seems to me that it ran better just after I changed the jets to #40's. O'rings could be a problem but the thing is that the bike runs a little different every time I run it. I wanted to say that it's definitely not the float height. The last time I messed with the floats, it was cold and I wasn't sure that I did a good job. This time, I did the best I could. Thank again, Joe  :hi:
Title: Re: Changed float height
Post by: Pat Conlon on May 12, 2014, 08:34:47 PM
To check your accuracy, check the fuel levels.
Title: Re: Changed float height
Post by: Joe Sull on May 13, 2014, 04:44:42 PM
Quote from: andyb on May 11, 2014, 05:54:25 PM
If it doesn't want to run cleanly while you're at that cruise, trying to surge and giving you a hard time holding the speed steady, look at the pilots and mixture screws


I took a 100 mile run today and evaluated. Your quote above is exactly what it's doing. I tried snapping the throttle from cruse in third at 2500 and I had no hesitation. When the throttle is in a neutral state (I think that what your calling cruse) it's stumbling. As soon as I add throttle, even just slightly, it runs perfect.

So I guess I'm looking at the pilot screws. Adjusting them seems to be a problem with me. I thought I had a handle on it with the blip test that was explained in one of the carb file outlines, then someone said it was oppisite. There 2 turns out now.

Question
Is there a way of adjusting them individually?
Are the plugs that go over the idle jet important?
Title: Re: Changed float height
Post by: jscgdunn on May 13, 2014, 05:14:47 PM

I took a 100 mile run today and evaluated. Your quote above is exactly what it's doing. I tried snapping the throttle from cruse in third at 2500 and I had no hesitation. When the throttle is in a neutral state (I think that what your calling cruse) it's stumbling. As soon as I add throttle, even just slightly, it runs perfect.

So I guess I'm looking at the pilot screws. Adjusting them seems to be a problem with me. I thought I had a handle on it with the blip test that was explained in one of the carb file outlines, then someone said it was oppisite. There 2 turns out now.


[/quote]

Joe mine was the same.  It is a 92;  I had mine at 2.5 turns out.  Went to three turns out and runs fine.  Try 2.5 turns out. 

Jeff
Title: Re: Changed float height
Post by: andyb on May 13, 2014, 09:49:36 PM
Quote from: Joe Sull on May 13, 2014, 04:44:42 PM
There 2 turns out now.

Question
Is there a way of adjusting them individually?
Are the plugs that go over the idle jet important?


They're*

Yes, but you're too far out yet it sounds like.  Back them to 2.5 and see how it feels.  Then 3.  Then 3.5.  Then 4.  If you're still not smooth at cruise, it's time to go up a size on the pilots.

No, the plugs are pointless.
Title: Re: Changed float height
Post by: Doity Eddie on June 03, 2014, 10:43:52 AM
"They are" = They're
Thank you!!
Not to worry, English is complicated.
There, Their, They're. :empathy3:
Title: Re: Changed float height
Post by: Joe Sull on June 03, 2014, 01:30:09 PM
Quote from: Doity Eddie on June 03, 2014, 10:43:52 AM
"They are" = They're
Thank you!!
Not to worry, English is complicated.
There, Their, They're. :empathy3:

Don't get weird on us man.  (popcorn)