idle set screws?

Looking for these idle set screws I hear so much about. Are they inside the float bowl? I downloaded a pdf that shows it on the bottom of the carb, but I don't see it anywhere. Getting a cough at low thottle when it warms up. 1/4 throttle on up, runs great. Want to try adjustment before I change pilot jet.

'82 maxim 650 hitachi carbs

 

it is ONE big knurled knob at the bottom of the carb rack, between carb 2 and 3, and it sticks out the back of the rack toward the airbox.

THAT is the IDLE SPEED adjustment.

The others that you hear about are the IDLE MIXTURE screws....they are on the top of each carb and are right next to the enricher plungers.

Turn your idle speed adjustment clockwise to increase RPM. It doesn't take much for it to come up, so tweak it, blip the throttle, tweak it, blip the throttle, etc......

I slide my hand in from the right, and can adjust it without burning my hand. Fortunately I have long arms, hands, and skinny fingers and can adjust it while sitting on the bike.

You will find that it may idle low when cold, and 'too high' when hot. You'll have to play the game til you get it right where you want it.

For the 650, you can also control the idle with the enricher lever at your left thumb.

I kept my 650 at an idle that I liked when it was good and warmed up on a good warm/hot day. On cold days, the idle would stay low, so I'd keep the enricher lever just slightly on when I'd come to a stop, and it would keep the rpms up just a tad. Then, when back to moving, I'd just push the lever back off.

Dave F

 

Found the mixture screws and also found them to be 4 - 4 1/2 turns out. So I seated them then set them to 2 1/2 turns out and increased pilot jet to #41 from #40.
Now when it warms up, I'm getting popping and rough idle. Going to try turnng them out a little more.

 

Found the mixture screws and also found them to be 4 - 4 1/2 turns out. So I seated them then set them to 2 1/2 turns out and increased pilot jet to #41 from #40.
Now when it warms up, I'm getting popping and rough idle. Going to try turnng them out a little more.

 

Are your valves in spec and have you done a running vacuum sync yet?

It sounds like you may be getting ahead of the game a tad...

 

I might be getting ahead of myself, but, I've always been my own worst enemy.
And I just can't wait for paint to dry!

https://www.youtube.com/watch?v=98mUC-v ... ata_player

'82 xj650, maxim,

 

I might be getting ahead of myself, but, I've always been my own worst enemy.
And I just can't wait for paint to dry!

https://www.youtube.com/watch?v=98mUC-v ... ata_player

'82 xj650, maxim,

 

You're trying to tune mixtures.

It's not going to work well if you're out of sync.

You can't get a decent vacuum sync until your valves are in spec.

So right now all you are doing is chasing your tail. And getting nowhere, which is all you'll get until you get the pre-reqs done.

 

So uhh, did you like the seat? How 'bout them side covers!

I suppose there's a write up for valve clearances?

Thanking you in advance

 

So uhh, did you like the seat? How 'bout them side covers!

I suppose there's a write up for valve clearances?

Thanking you in advance

 

Yes, there are plenty of write-ups about valve clearances.

 

Valve clearances: http://xjbikes.com/Forums/viewtopic/t=14827.html

Part Deux: http://xjbikes.com/Forums/viewtopic/t=29209.html

Wet-setting float levels: http://www.xj4ever.com/setting%20fuel%20levels.pdf

 

Ok, just got the tool.
1)E: .007 (.178) 2)E: .004 (.1016) 3)E: .008 (.2030 4)E: .007 (.16~.20)


1)I: .004 (.1016) 2)I: .005 (.127) 3)I: .008 (.203) 4)I: .004 (.11~.15)

1) Intake, shim "1280" (2.8mm)

That's as far as I got. Guess I'll need shims. A=(B-C)+D
A= New Shim Thickness
B= Recorded Valve Clearance
C= Specified Valve Clearance
D= Old Shim Thickness

Oops, measured in inches.
The two that look interesting are #2 Exhaust, and #3 Intake