Can’t get idle speed to stay set.

So I have adjusted the valve all in spec now. I’ve added the idle adjuster screw with a bushing to the center of the carbs. Checked spark plugs. Connected a manometer to the carbs. So the problem I’m having is a can set the idle to either about 800-1000 to low or 3000, to high.
When I set it to 800-1000 it will idle till I advance the throttle, then it stays at 3000-4000. Turn off the engine and it starts at 800-1000 again, hit the throttle and it revs and stays there. I’ve sprayed the intake manafolds with water to see if it changes, and it doesn’t. I can sync the carbs at 3000 rpms. Any ideas would be helpful.
Thanks Marc.

 

Air leak somewhere. When it is idling direct some propane around the carbs, especially the intake manifolds and throttle shaft o-rings. If it speeds up you have found the air leak. Mine was the intake manifold gasket.

 

Thanks. I’ll try it in the morning. Is the idle setting normally very sensitive ? Mine is super sentive.

Another off topic question, I was looking st xj4ever’s to buy a few items, but I don’t see a “ add to shopping cart” or a way to place an order. Is there something I’m missing ?

 

Idle should be steady when warm—just like your car. It has been a while since I needed anything from Chacal, but I have ordered several items at the same time. Send him an e-mail and he will get you started.

 

Thanks for the help.
Marc.

 

The sensitivuty is due to the vacuum leak.
Were the carbs fully disassembled and the throttle shaft seals replaced?

Moving forward, please keep all questions in one thread so we can better keep track and not lead you astray.

 

Thanks K-moe, I’ll keep all question on this thread.
I do have a question , as a new member I find it hard to search for things that pertain to my bike xj550h. I understand that all xj’s are the same, with only some things different. I find myself reading a lot of threads, then find out there are talking about xj750’s or other models. Would it not be easier to have sections in the forums setup as per bike model, it would make it easier to just read things about the bike each person has. I only ask this because my V-Strom forum is broken down to engine size and even gen1,gen2, and gen3. My klr250 is a group all by itself.
Please don’t get me wrong, this forum has a huge amount of knowledge of these Yamaha’s on it, and you are all doing a great job of running and maintaining it.
Thanks Marc
Xj550H

 

To order from xj4ever start an IM message to him with what you need , he will send you a quote number back once you have done this a couple of times it is easy.

 

Thanks jet. So to IM him I need to find him on FB right ?

 

All XJs are not the same. There are six distinct, main groups (as I think of them anyway):

The XJ400 family (which includes all of the chain-driven bikes)

The Aircooled XJ 650/750/700 family (which includes most of the shaft-driven models)

The Watercooled family (which consists of the Maxim-X alone)

The XJ1100 which is based on the XS1100, but is not quite same=same.

The fully faired 1984/85 models (The XJ750/900) which were intended to re-light the XJ line, and share many parts with the earlier shaft-driven bikes (the 900 being redesigned/reengineered and renamed as the Diversion 900, which then gradually became the XJ1300)

And finally the "Mini Maxim" which had a parallel twin, and was built as a promotional tool for the launch of Yamaha's Midnight series of bikes.

The above list does not include all of the special sub-models that were built for various police agencies, or the Radian. I suppose they could be lumped together in a "parts-bin-bike" category.

As for the forum layout; that was decided long ago by the forum owner, and would be a full time job to re-organize. I spent my first year here just reading as many of the old posts as I had time for; treating it like a good book. The forum has grown organically, and that process will lead to what we have.

The best way to find information (aside from just asking) is to do a google search of the site with your model included in the keywords, followed by the command: site:xjbikes.com

 

You do not. Along the top right of the page, just below the ad for Xj4Ever, click on the link for your inbox. A menu will open. Click on start a conversation and then begin typing in chacal's username.

 

Thanks.
Looking at buying carb kits and intake manifolds.

 

Len (xj4ever) will help you big time, with your bike problem and through the transaction. He'll get back to you pretty quickly, even on weekends and odd late hours. You'll have to put money into an account via Paypal to pay for your transaction purchase from him. I had never done a transaction this way before, that was over 5 years ago, and was kind of "what" at first. Since then, I have used this method of payment with multiple vendors. Once everything is set up its easy.

 

I'm not sure what bushing is needed with the idle adjustment screw, unless its the one on the screw holder bracket assembly . Could the screw be attached or assembled incorrectly?

 

maybe i missed adjusting the idle mixture. why not try 1/8 turn in and out on each one. maybe you'll find nirvana, like that guy in the bushes

 

Thanks Larry, looking forward to getting running, not looking forward to doing the carbs. I don't mind my single carb, but 4 is going to be different.
Is the idle mixture screw a fuel screw, like out is rich, in is lean?

 

Correct. Baseline is typically 2 1/2 turns out from a soft-seat, then width-of-a-dime adjustments until you find the sweet spot.

 

Would plain old Starter fluid work equally as well?

 

Yes it will. I usually use carb cleaner and the red plastic tube so I can apply it with some degree of control.

 

So I did a compression test, 148,140,148,150. So that looks good, hi compared to the manual. Also when I took off the manifolds, I noticed I didn't have any gaskets between them and the heads ! They are gaskets there, right?
When I was spraying starter fluid on the carb shaft and intake manifolds, I couldn't get a diffent, there is the leak, so I'm going to febiuld the carbs and knew manifolds.

 

You unbolted the intake manifolds from the engine and there were no gaskets?? Was there some type of gasket sealant or anything there? My 700 has gaskets and one was torn and about 1/4 of it was missing. I made one out of some gasket material I had and that solved my problem. I find it hard that it could ever run right without gaskets.

 

Yes, no gaskets, I'd show u a picture, but they r to large to post.

 

There is supposed to be a paper gasket at each manifold flange. I like to back them up by using a spray-on gasket dressing (Permatex makes an excellent copper-impregnated spray). The key components on the carbs that lead to vacuum leaks are the throttle shaft seals and the idle mixture screw o-rings.

 

Use an image hosting site like Photobucket or imigur. Linked images can be of any size you want, so long as it doesn't require us to scroll or zoom-out to see them (usually that's automatically constrained by the hosting site).

 

Thanks k-moe. So do all the shaft seals need replaced, or just the ones on the end.
I tried permatex, no go, that isn't where it is leaking from. Looking at the parts list to rebuild my carbs, sucks, it will cost 4 times what I paid for the bike. And how long will it last if I don't ride the bike for a few months during the winter ? Will get very costly to own a four cylinder bike real fast. At least I have taking carbs on and off down to a science, like 15 min.

 

You have to break the rack ..each carb is held into the rack with 4 screws , to replace the inner shaft seals , you have to remove the 2 screws on the butterfly plate and remove the 10mm nut and slide shaft out of the carb body. This is in the church of clean ...once ALL rubber seals and O rings pulled it will be cafe to soak the carb bodies. I use a 1 gallon of Berrymans carb dip this has a basket included , soak one carb body at a time soak for about 45 minutes , take out and wash in hot soapy water and let dry for about 30 minutes and reassemble. Xj4ever has the butterfly shaft seals , if you do this right you will get several seasons of use ,and should not have to redo this .

 

Ok.

 

Just curious isn't the max compression 135 psi for the 550's? That's off the top of head so I'm not positive but pretty sure.

If your breaking the rack for the first time I'd pull all jets so you can clean everything properly. Before doing that I'd soak them with some kroil or something similar so they are easier to remove.

Also, if there's any other rubber orings that need to be replaced nows the time to replace them. The fuel supply rail orings and "T" should definitely be replaced if they haven't.

Honestly the hardest part is the wet set and getting the carbs in and out.

Do it all once and you'll be very happy!!

 

An old muffin tins helps keep everything organized..

 

The manual says 121psi at sea level. I don’t know why mine is so high. It says to keep cranking till your read don’t climb anymore. That’s what I did. Many 6-7 turns of the engine.
I’m looking at the rebuilt kits, plus new jets and seals for the shaft.

 

The Permatex isn't to fix the leaks you have, it's to dress the new gaskets to ensure that they seal well.
permatex-copper-spray-a-gasket-hi-temp-sealant

Once rebuilt, the carbs will be good for decades, unless you fail to prep the bike for storage each winter. Nearly every fault in a used motorcycle is there because of abuse and neglect (there are a few things that just need to be replaced due to age, and that's unavoidable).

So far as costs go;
How much is a new motorcycle?
The last time I checked prices on equivalent machines I found that I've saved at least $10,000 by refurbishing my Seca.

 

So what be done to put I bike into storage for the winter? I'm sure all here newbs complain about carbs all the time, I'm sure I'll get over it. It new to me, and learning it is what I got the bike for. I also have a dl650, that was cheap, and runs flawless with no real maintenance. But it is a 2006 and a still ride it a lot. I rebuilt my klr 250 engine and carb over last winter, and will admit it me about a month to get it to work perfect again.

 

I fill the tank and put stabil and a few ounces of marvel mystery oil in tank , and drain the bowls and with a large syringe fill thru the fuel line a mixture of marvel and stabil . And put battery on a tender and wait out winter , when spring comes , drain float bowls and set petcock to PRI set choke to open and start it up usually smokes a little but will clear up . This is just what I do , some just use Seafoam, oh I should have added keep petcock to ON if you have stock vacuum petcock this ensures fuel wont keep flowing and might fill crankcase full of fuel. Cheers

 

Thanks, I was wondering about Avgas, it is what I use in all my garden equipment and it doesn't go bad like gasoline. You just can't use it in anything with an O2 sensor as it is leaded fuel. I use 100LL in my stuff.

 

Avgas is gasoline. It just has a higher octane rating (which none of your engines can benefit from, unless you have built one for that purpose).
You can use it for the last tank of the riding season, but I don't think it's worth the bother and expense to do so.

My winter routine is to add Seafoam and Stabil to the last tank, go for one last ride to make sure the engine oil is warm enough to cook-off any moisture, drain the float bowls after the ride, and let her rest in the garage under a breathable cover.

As for gas going bad....that depends. I've had E-10 sit in a carburated pickup for three years (no fuel stabilizers were added) and the thing started right up after priming the carb. I then proceeded to drive it 400 miles before refilling the tanks. There's always variables.

 

True. Avgas, doesn’t go bad like gasoline. I’ve had pilot leave it there tanks for years and then go fly. Avgas doesn’t have the additives in it like gasoline does. I’m not worried about the performance gain. Really you look a bit of power as the engine isn’t made to run it, as you said. Avgas is free from where I work.

Well I have the carbs all apart, wow there are some really bad mechanics out there. #1 carb might have to be replaced as one of the stands is broke at the top for the float. I’m sure they tried to beat it out. My carbs all have the Black floats and all the drain screws are very bad. Had to use valve grinding compound to help get them out.

 

You lucky.......

 

The drain svrews are problematic, mainly because most owners don't even know thery are there, or what to do with them. I've had plenty that needed to be drilled out.
The floats are supposed to be black, and I've never found one that failed to float.

Put up a pic of the broken float pillar. Repair is possible, but how to do it will depend on what the break looks like.

 

Cool. One of the easier types of brake to fix.

Cut or mill the pillar so it's flat, and short enough so the joint for the repair will be below the hole for the float pin.
Drill and tap the pillar for a shoulder bolt (if you can score an aluminum one, all the better, but steel will be fine).
Install the shoulder bolt into the new hole you made in the pillar. Depending on what type of head you chose for the bolt you may want to remove that head for clearnace.
Using the existing hole in the undamaged pillar (and a good deal of care) drill a matching hole in the bolt (this is where an aluminum bolt makes things easier).
Your float pillar is now repaired.

 

Thanks for the help, again. Sounds like a cool repair.

 

I forgot to mention that it's advisable to use a lock washer (the internal-tooth type work well for this), or drill a second hole (lower down) for a roll pin to ensure that the shoulder bolt will not back out.

 

I'd look for a new carb body.

If you'd like to do it yourself here's a link.

http://www.yamaha-triples.org/workshop/Mikuni_MKII_Post_Repair.pdf

 

what carb body is it with the broken post?

 

Number one for a xj550 Maxim.

 

I will look to see if i have one , if you do not want to try to repair the one you have or have a problem repairing it.

 

if you could drill a hole in the post perpendicular to and just under the pin, maybe you could put a wire through the hole, then up over the pin and twist it tight.

 

I love the attention to detail and ability of enthusiasts to be able to successfully pull off a repair like this - that saves an otherwise good carb body from the scrap bin.

 

no luck on the spare #1 carb body

 

Ok, So all my carbs are clean, but on #4 carb I get very little air flow through the port that goes from the pilot jet up to the air jet and over to the pilot screw. My other carbs blow air pretty freely from the air jet to the pilot jet passage, so what is the next step ? Can I take out the small little brass balls to blow out the passage?
Thanks for your help Marc