A journey through a hanging idle.

#3 does not have a adjustment screw. It is adjusted by the throttle knob. The other three are being adjusted to #3.

1. Adjust 1 to 2.
2. Adjust 4 to 3.
3. Adjust 2 to 3. The #1 carb is linked to #2 and will be brought along with the adjustment.
4. Adjust the throttle knob. This will open/close all four butterflies simultaneously. Hope this helps.

Gary H.

 

Yep, this is the method as described in the XJ manual.

 

i think the 1/2, 3/4 are interchangeable just so the idle is kept in check and 2/3 is last.
the shims under the needles might be part of the problem with the black plugs.
looks like Sunday will be nice enough to ride, would you mind a visitor?

 

Agreed. After he's done it a couple times with success this should make sense to him as well.

Gary H.

 

After that THIRD sync in 24 hours, it looks like everything is back to normal. Before I did the final sync of 3-4, 1-2. and 2-3, I seated the idle/mixture screws and pulled them back 3 turns. While the motor was warm, I took a quick ride and everything seemed back to normal (will know more about the plugs and hanging idle tomorrow).

I think that I was a little sloppy with the first two syncs in that on the first one, I did it completely wrong, and on the second, I was not patient enough to really watch the fluid for a long enough time.

After I take a ride tomorrow, for the hell of it, I'm going to pull a washer off of the needle, leaving it at one instead of two to see what kind of difference, if any, that makes.

Also, yes there is spark to the #3 plug.

It looks like I need to get some NGK plugs, just for piece of mind. That broken piece of ceramic is unsettling.

Polock, would love to finally meet you. I'll send you a message shortly to se if we can work something out.

As stated earlier, this is my current setup on the 1982 XJ750 Maxim:

124 mains
Stock Pilots
two washers to shim the needle and raise it.
Pod filters
Stock header to collector, no muffler.
idle jets turned out 3 screws.

 

SQLGuy, i could use a little help. I am in the Springs.

 

Back again. Haven't had a lot of time until the past day or so.

After posting the above specs:

124 mains
Stock Pilots
two washers to shim the needle and raise it.
Pod filters
Stock header to collector, no muffler.
idle jets turned out 3 screws.

I'm still having the same issue of a slight hanging idle, and an extremely lean third cylinder. I have not checked compression, but I DO have spark to it.

So what haven't I done that I need to do?

Check for air leak: Picked up a propane torch.

I'm also going to adjust the carb fuel levels and float settings, but before that:

I measured the valve clearances, and I'm wondering if this is part of the hiccup.:

Exhaust 1: Exhaust 2: Exhaust 3: Exhaust 4:
.22mm (lots of force to get in, so more like 21mm) .19mm .19mm Tight .19mm
Y275 Y290 Y255 Y260

Intake 1: Intake 2: Intake 3: Intake 4:
.11mm .15mm .15mm .15mm
Y290 Y290 Y290 Y280

Is this weird that none of them got tighter aside from Intake 1? And that Exhaust one is completely out of spec compared to the others?

Would you guys suggest me changing any of the shims besides Intake and exhaust one, since everything else is in spec?

Thanks everyone. I'm going to keep this thread rolling until we get sorted out.

 

If it has not been said before, when you use PODS you are in uncharted waters. The air box in these bikes were designed the way they are for a reason. With PODS, you play with variables until you get a result that you can live with.

I am looking to purchase another bike. When I see PODS on the bike for sale, I immediately click NEXT.

 

#1 exhaust is slightly out of specs (on the loose side) but intake #1 is still slightly in (but definitely on the tight side). So you should get a 280 shim for your #1 exhaust valve.

If your #3 cylinder is runny lean, it is obviously not related to your valve clearance on this cylinder,

 

HalfCentury,

I utilized pods knowing full well what I was in for. As the post said, everything ran great all summer using a setup that several others with pods and modified exhausts used, with no trouble. Since I developed the hanging idle I decided to basically do over the 3k mile maint while making sure I have no air leaks. If I have to play around with the jets again in the spring so be it, but before I put it away I'm going to take care of these valves and carbs once more. I rode this thing a lot over the summer and it may just be time for a tune. I'm simply posting my results as I go along and looking for insight along the way.

Tonight I'm bench syncing and going through carb three to look for any clogs, I'm also ordering a colortune. Could anyone tell me the proper plug diameter to pick up (10, 12, or 14 mm)? And do you guys recommend the Gunson or the Morgan Colortune?

Thanks!

 

14mm Colortune, and, they are all made by Gunson. Morgan is just one of the re-sellers of the Gunson Colortune.

 

Your vacuum sync needs the YICS tool. Performing a bottle sync without the YICS tool is a waste of time. Have you obtained the YICS tool since your initial post?

 

I have not, actually. That's a good call. I'll make or order one today.

Chacal, thanks for the tip sir. Will report back after setting fuel levels/changing the exhaust shim, vacuum syncing (with YICS), checking for leaks, and colortuning.

 

There is an ongoing debate about that issue. Several of us have been able to synch the carbs successfully without using the YICS tool, and without using any special tricks to compensate for not using the tool.

 

One thing that hasn't been explored. When you put the rack back together did you make sure that the carbs were all aligned properly, and that the throttle plates snapped shut with all the vigor of a mousetrap?

 

Nice phrase..k man.

 

Ok. Understood. As a suggestion, perform the sync without the YICS tool and when finished, insert the YICS tool and check the balance. That would convince me.

My contribution to the discussion is that after my bench sync, one pair of carbs was horribly out of balance. Even though the bike started and could run, it was not properly tuned. I used the YICS tool and the results after the carb balance were amazing. The bike was a rocket.

 

when i ride the bike there is no yics tool in it. That is how i want it tuned

 

Mine are balanced within the error rate of my manometer without using the YICS tool, and it flies like a rocket too.
Will the YICS tool help? Sure.
Is it worth using? Debatable.