Air mixture screw

82 xj 750 maxim, so to correct my previous statement 1&2 are white and 3&4 were black,

 

So went for a test run tonight, happy to say no leaks and new mufflers work great and didn't fall off haha, but I had the bike ideling good in the driveway then I left drove for about 10 mins pulled over and the bike stayed at about 3000 rpm when stopped so I turned the big idel knob down so I had a good idel again, I should mention when I say good idel I can also rev it and it will drop back down to normal, then I drove for about 10 more mins stopped and it stayed high again, am I adjusting it wrong? Seems like the I turn the idel up for warm up then I gotta turn it back down once it gets hot, o ya 82 750 maxim

 

And I haven't adjusted the the air mixture screws yet I was gonna do that tomorrow and the carbs are only bench synced cause I haven't made the homemade tube gauge yet

 

The engine will idle at a higher speed when it is fully hot than when it is just warm.

You will want to adjust the idle mixture screws and perform a running synch to be sure that all cylinders are being fed equally, or your idle will never settle back down consistently.

 

Ok I'm gonna do the mixture screws tonight, so should I set the idel when the engine is fully hot?

 

If you do the whole process at once the engine will be hot enough.
You will be adjusting the idle speed as you perform the running synch. It may need to be adjusted again after your first ride.

 

Gotcha ok thanx

 

O ya I have a yics engine and I read there's holes to plug while you sync, where are these holes and what's the best way to block them while sync,

 

Dont bother. Not only do you run the risk of breaking the casting that the plugs thread into but in my experience there isnt a noticeable difference between being blocked off or not when syncing. Other opinions vary.

 

If you can live with a synch that's only 99% perfect, then don't bother with blocking the ports.
As a practcal matter you won't be able to tell the difference.

 

Sweet ok I can live with 99%

 

So I watched a video by David Allen on carb sync, he had 2 baby bottles, do any of you know what fluid was in those bottles or what fluid I should use? And from what I gather carb 3 is home base, there's 3 adjust screws on the back of the carb are those for 1,2 and 4 carbs? if I'm on carb 2&3 would I just move the vacuum line from the gas tank to 1 or 4? What do I do if the fluid in the bottle gets sucked into the carb?

 

How To: Make a 2 bottle synch tool
running-carb-sync.61677

And even though this might be redudndant, you won't get a good synch unless the valve clearances are in spec.

 

The valve clearance is good I did those, all 8 were out big time, I had to drop 2 sizes on a few of them

 

O ya forgot to mention I did my mixture screws they felt about 4- 4.5 turns out, I seated them and turned them all 2.5 out but then when I started the bike it seemed like it was really starving for gas or air I couldn't turn the big knob fast enough before it stalled so I turned em all so there 3 turns out seemed to help a bunch, I'll probably stop messing with it till I do that carb sync

 

Have some patience, and be prepared to spend quality time with your bike. Setting the mixture screws is not a fast job.

You want to do it right so you don't have to mess with it again for a long time.

It's been a few years since I did my carb sync. I ride year-round and I am shocked everytime I rev her up and she still sounds like a tuned sewing machine.

 

I defenetly wanna do it right, I've fixed and adjusted a lot of stuff so far and now I'm just down to this idel thing, I know for sure it's been at least 4 years since the last sync cause that's how long my buddy had it before he gave it to me, so who knows when it was done last,

 

So I got a pretty good understanding of how to do a running sync I read a bunch of threads on here, but there's one thing I didn't see, is there a setting that the idel knob should start at? Like the 2.5 turns for the mixture screws, or just play with it till I got a steady idel then start the sync and adjust as I go. I couldn't find your write up k-moe but I did read one with pics of a carb and which way to turn screws

 

The idle speed knob is what sets the #3 throttle plate during a bench synch. If you did that, then you will only need to adjust the idle speed knob a little as you do the running synch. If you did not do that, then you will just set it as close to the factory reccomended 1100 RPM as you can before performing the running synch.

You may find (as many of us have) that your cold starts will improve if you bump the hot idle speed up to somewhere between 1200 and 1400 RPM.

 

Ok thanx I'm gonna pick all the crap up I need to make a gauge and do it Saturday morning