carb float issues

I am cleaning my Hitachi carbs on my 82 maxim xj750j. I recently bought the bike and it runs rough and doesn't want to idle. Previous owner said it ran great couple years ago and he put new needle and seat into it. As I cleaned each carb while following my Haynes manual, I saw needle and seats where new and had no blemishes. Two problems. First, the clips that attach to needle and hang onto the tang on the floats where missing on #2,3,4. And #1 was bent a little. Problem two. When bank of carbs is upside down the floats on #1,2 are adjusted differently than #3,4. #1,2 are adjusted high so very little gas is sitting in bowl and #3,4 look to be adjusted correctly and sitting about even with carb body. I pulled the spark plugs and found none of the cylinders appear to be burning rich. All plugs are lightly brown. I read chapter on how to adjust and check floats its a lot of work removing carb to make adjustments. Is there any way to get me close with out haveng to remove them the and time again making small adjustments to the tang on the float? Possibly a way to align with carb body to get me close to a starting point. Thanks for all it help. Bill

 

Can't say it better than this:

http://xjbikes.com/Forums/viewtopic/t=9 ... eight.html

Good read here:

http://xjbikes.com/Forums/viewtopic/t=2 ... loats.html

free hanging explained well by this guy-highly technical measuring tool

http://www.youtube.com/watch?v=SiUDoXiPcKE

PS-Another PO does the incredible and loses carb parts!! Previous Owner=Pissed Off current owner.

 

Awesome info. Thanks so much, glad there are so many helpful people out there who dont mind helping us out who don know so much and dont learn good. lmao!

 

One other question. My manual neglects so mention whether the bike needs to be running or off when checking fuel bowl level. It said to start it and warm it up and to ensure fuel was in the bowl to the proper level, but then it didn't say to shut it off or leave it run. I would think it would need to be off because of the vibrations. Any ideas, on or off after warm up on checking fuel bowl level? Thanks again, Bill

 

Besides changing throttle shaft seals, float levels tend to be the biggest PITA for me. With that being said, take the carb rack off the bike and plan to spend at least a couple hours getting the float levels as accurate as possible.

WET-SET method! Fill 'em carbs with gas using portable tank and let it flow into the bowls. Keep it 'flowing' so you know the floats work when they reach their maximum setting. Check each level using clear tubing and then adjust the floats as needed. Yes it can be a tedious process filling carbs, checking float levels, then draining the carbs to change float settings, then do it all over again several times. That's the pita part of it. But once they are all correctly set, you'll be loving the results. Trust me

In regards to your last question, I haven't even attempted to check float levels with carb rack still on the bike. I would think it would be too much of a hassle. Just take the entire carburetor rack off the bike, clean the bageebers out of 'em and wet - set your float levels once. Do it all once slowly and accurately and you will have great results.

just my two cents...

 

Can improperly set floats cause bike to run rough and not idle? I know it can lead to filling crank case with gas. How do I keep it flowing when filling carb with gas to check the wet setting? How do u know when carb is full and needle is seated?

 

If you haven't already, take a gander at this:
Setting the fuel levels

Something Chacal and I whipped up. Easiest way to supply fuel to the carbs when wet-checking the floats (far easier to do with the carbs off the bike) is with some sort of auxiliary fuel tank.

If the bowl in question is full and the needle seated, the fuel level in the measuring tube won't keep rising. Plus, with the carbs off the bike, if a carb does overflow, it'll spill onto the ground instead of through the cylinder and into the crankcase.

 

My son and I dry set the floats to 17.5mm. Yes I canted the carb so the floats just contact the needle when making the adjustments. I also just want to add that if you have a nice digital caliber (I happen to have one from my days as a diesel mechanic), they will often have a depth gauge that slides out the bottom/end of the caliber as you slide the wheel. I forgot all about that handy feature and I cant tell you how easy that made checking the height of the float. I hope this helps somebody else out there that happens to have one or know somebody who does. Then we put the bowls on and flipped it over. Leveled the carb both directions. Connected to fuel source and proceeded with the wet test. I'm happy to report that all four where from 3.4 to 3.7 mm. So I'm within spec and waiting a new #2 intake from xj4ever.com. should be here wed or Thu. Can't wait to put them on and ride man.
It seemed like the bike ran real lean or was sucking air. Here's what I found. #2 intake leaked gas because of a major tear in it. #1 and #2 floats were set to high at about an inch high, and I believe 17.5 mm is roughly 11/16. #3 was spot on and #4 was a little low. So I think I found all the problems and did a major thorough cleaning on the carbs. Throttle shaft seals where perfect. What do you guys think. How did I do for my first time in the carbs. Needle and seats where supposedly replace two years ago. They looked great with no blemishes either so I left them. No leaking from carb as I wet checked the floats either so that's a good sign right? Thanks to all of you who helped along the way. Bill/MN

 

Good work, hazmat, glad you rechecked with fuel, the dry settings have been known to be way off.

 

Thanks, I've heard about that nightmare on previous threads. I unfortunately/fortunately learned from others misteps but that's were here. Helping each other out. Bill

 

Well, got the carb back on and started right up. Let it warm up but could tell it was running a little rich. Got back from quick test ride and idle was at 4000 rpm. Adjusted idle down to 1000 rpm and after another test run ran much better. Idles perfect. Only one small problem. When I went by the driveway and let off throttle my son who was watching and I could hear light popping coming from exhaust like its still getting to much gas. It's very quiet and can hardly tell while riding. I don't have any ideas as to what can be causing this. Rides great though. Just want it perfect. Will a carb synch fix this quiet little popping back firing type sound. Again its very quiet and sounds muffled like. Thanks Bill

 

"Popping" generally indicates a lean condition.

A good vacuum sync, and then fine tuning the mixtures should fix it.

 

My mistake. Thanks for the info. The book says there are no other adjustments to make other than idle speed. But I hear about color tune and other xj owners doing this. What is this and how is the procedure done. Where r the mixture screws located. Thanks, Bill

 

No problem.

The books don't "admit" to the mixtures being adjustable as they were EGA-set from the factory then capped.

"ColorTuning" involves the use of a ColorTune device, which is a special spark plug with a clear body that allows you to "see" into the combustion chamber and adjust mixtures according to the color of flame being observed. This is the most practical alternative to using an exhaust gas analyzer like the factory did; and a more accurate way to adjust the mixtures than trying to do it "by ear."

Mixtures screws are located on top of each carb, adjacent to the float plungers. Yours might still be capped.

 

If I remember correctly, was there a post I seen here that mentioned drilling out the cap to get at the screws or am I thinking of something else? Is the color tune device expensive? U adjust to get the color burn in the cylinder? I take it its very accurate and handy?

 

That is correct, if the caps are still there you drill a small hole into them and run a small sheet metal screw in and pull them out. You need to be careful not to drill too far and hit the screws.

The ColorTune is not expensive; generally under $50 shipped.

You adjust the idle screws; the Colortune allows you to see the color of the "fire" in the combustion chamber.

The accuracy depends on your eyes; it is indeed very handy.

 

Thanks I appreciate the help.