85 xj700 non-constant idle rpm and stalling.

Recently reset the float height on the xj700 to 16mm like the service manual said. before I did this the bike would start and idle, the idle would climb very high. Now after I adjusted the floats the bike will stall after twisting the throttle open and the idle doesn't come down very fast either. I'm at a complete loss at this point. any idea to get me pointed in the right direction would be much appreciated. I can provide pictures of anything if needed.

side note: in the XJ700N parts manual it states the float height should be 11.3mm~13.3mm.
in the service manual it says they should be at 16mm.
I made sure each book was for the Xj700n and they were. Is this a mistake of some sort?

 

Have the carbs been to "Church of Clean"? And second pic , that little hole on bowl has to be clear, often overlooked during cleaning. Last pic is throttle shaft seals from an Xj700n set of I have done recently.

 

Carbs are clean, all holes are clear of any and all gunk. I should add my idle mixture screws are all turned to 2.5 turns as well.

 

Have you checked for air leaks around intake with wd40 or propane etc. Bad throttle shaft seals are notorious for idling problems

 

You need to wet set your carbs for the proper fuel level in bowls.. thats likely your problem.
the higher you set the floats the lower the fuel level.

16mm float height is used to give you a common starting point for your floats so you can do a wet set of your carbs.
waste of time except to know where you are starting from for the wet settings

now the fun starts

Setting the fuel levels

-Fuel level measured via the clear-tube gauge: 3mm +/- 1mm (.12 +/- .04 inches) Hitachi HSC33 series (XJ700 aircooled models):

 

Havnt been ignoring this tbread, ordered everything I need to wet set and sync the carbs. I had not known about the wet setting. When I get my package from Len ill do the tests and let y'all know how it went.


Side note, I replaced the throttle cable from before and WOW I didnt realize how crudded up it was. I can actually hear the butterflys snap shut now.

Also, anyone have some tips on how to get the rusted and stripped drain bowl screws out? Have two that are smooth and two that are stuck. Already ordered the aftermarkets from Len to replace them all.

 

Very careful drilling. The aftermarket ones will bring you joy!

 

Drilling, and heat. Drill though to relieve pressure. Heat to expand the aluminum. And a good extractor to undo the drain screw. Go slow, and if you notice that the extractor starts to deflect (twist) even a tiny bit, stop or it will break off and you'll be pooched. IF th scrw is rally stubbon it will ned a long soak in a 50/50 mix of ATF and acetone (or a good penetrating oil like Kroil or PB Blaster).

 

So I was reading that I should stick to as stock as possible with these bikes, I had replaced the old foam air filter that was pretty much disintegrated with the K & N wire and I think a paper material filter. Does this one cause too much air to enter the carbs and should I buy the red foam one instead.

 

I don't know about the K&N filters, but I've always heard that they were high flow filters in cars. The UNI foam filter was in my XJ700N when I got it. It is definitely not stock and should be replaced with the stock paper filter. When I replaced my foam filter with the stock filter it made the bike run very rich and I had to close the pilot screws to correct the situation. By the way, after cleaning the carbs, wet setting them, syncing them, replacing he air filter, and getting the valves adjusted I used a colortune plug to set the pilots at a lean position, installed new plugs and over time opened the pilots until I got a nice tan color on each plug. My bike went for getting less than 30 mpg to about 40 mpg overall and starts and idles well.

 

Paper filter from EMGO or Yamaha. All others require rejetting.

 

Where can I find the emgo paper filter? Cant seem to find it anywhere for the xj700

 

My mistake. I didn't catch that you have a 700. OEM is the only paper option for it. Start a conversation with Chacal.

 

Well after getting the UNI foam filter oiled up and installed, the floats set at 1mm, and the carbs benched synced as well as synced on a EMGO carb sync tool the bike seems to run a bit better. However...the carb sync tool says all the carbs have a valve timing problem? I got them all set to 6 inches.

another problem i'm having now is getting the bike started with full choke. When I hit the starter button the starter motor makes a grinding sound with puffs of smoke sometimes. to start the bike I keep needing to twist the throttle a bit until I get it started but once started it runs. idle drops when revved and all that.

 

http://imgur.com/a/Dov1k

https://m.imgur.com/a/vGXKr

They wouldn't show up on the website sorry, maybe too high quality Idk.

 

You are probably getting too much air through the Uni foam filter. The Uni filter never worked well for me. You might have to open the pilot screws a bit to get enough fuel.

 

Ignore that. The gauge is refrencing a different sort of engine.

If the stater clutch is only grinding sometimes, you're OK (for now).

 

It grinds everyime I try to cold start, I almost wonder if over filling the oil could cause something to slip and not catch? I have no idea. But I guess I retract all previous statement about it idling well lol. Went back out to start it again after it cooled down and when I did get it going touching the throttle dropped revs and killed it...