Idle

Hi just got my bike on the road and the bike idle fine until i ride it then it idles at or above 4-5 rpms until i work it down by using the clutch please help

 

Valves in spec?

Accurate float levels, wet-set? (INDIVIDUALLY wet-set, to spec.)

Running vacuum sync, with YICS blocked?

Float levels will contribute to "hanging idle" on the Mikunis; however it's usually a sync issue. You need to be sure the motor is fully warmed up before you do the vacuum sync; and the valve clearances need to be in spec before attempting a vac sync.

It won't "idle down" correctly, especially once warmed up, until all of the above is spot-on.

 

Tried most of that other then the valve the valve check seem to be really hard to do

 

No it really isn't hard. Valves are way easier than carb work, and only slightly harder than changing the oil. It takes a little while the first time, but it isn't something you should be afraid of.

Take a look at this, same engine as yours.

http://xjbikes.com/Forums/viewtopic/t=14827.html

 

Bench Sync the Throttle Plates with Resume' Paper, Strips of 3x5 Card or Strips of 35mm Film.
Assure that the Throttles are ALL able to CLOSE after the Bench.

Anchor the Throttle Cable.
Slack the Cable and Tape it to the Center Tube.

4,000-5,000 rpm's means the Engine is running on MAIN JET Fuel.
Throttles are OPEN
Check that you dont have "Sticking Diaphragm Pistons"

Make sure that Manifold Clamps are right-side up and not fouling the linkage.

Adjust the Cable Tensioner up near the Handlebar Control for Slack.

 

Ok I bench synced the carbs the bike is running better but the idle after in warms up Is idling fine after I work it down with the clutch

 

You're not going to get any further unless you pay attention:

GET THE VALVE CLEARANCES IN SPEC.

FIRST.

THEN DO A RUNNING VACUUM SYNC WITH YICS BLOCKED.

Then it will idle down on its own. Until you do, IT WON'T. NO AMOUNT of "fiddling" will fix it; YOU HAVE TO DO IT RIGHT.

You can't simply ignore your valve clearances because it seems difficult. You have to do them every 5000 miles, so you'll need to learn how.

 

Ok I will try that

 

I it is getting better and I am going to do the valves when I get a chance the for all the advice

 

How many miles on the bike?

The valves were supposed to be checked at 3000 miles to begin with.

They needed to be checked every 5000 miles after that.

If the bike has anything more than about 15K on it and they've been ignored, you're in the "danger zone" for a burnt valve.

It WILL NOT run correctly until you've done the steps that I outlined. It just won't. Honest.

 

It has just under 40000 miles by the way where do I get the shims from and I am planing on checking the valve Thursday

 

Oh by the way how do the go out of spec

 

They tighten up.

The valves "pound" themselves into the seats and the clearances tighten.

Left unattended long enough, they won't close fully any more, especially once hot, and then you burn a valve.

There are how-to's on the procedure; study them and get it done: http://xjbikes.com/Forums/viewtopic/t=14827.html and Part Deux: http://xjbikes.com/Forums/viewtopic/t=29209.html

Put it off long enough and you WILL damage the motor. If you think adjusting them is "hard" you don't want to be pulling the HEAD.

And it does need to be done every 5K. Do you plan on keeping and riding the bike? Then you need to learn this.

XJ4Ever carries aftermarket shims; and member Hogfiddles runs a "shim pool" exchange program.

 

Now that you are about to venture into Valve Adjustments and Critical Maintenance, ... you should acquire a YAMAHA Factory Workshop Manual specific to your Bike.

You got a question or need to know how to do something on your bike, ...

The answer is in the Factory Book.

 

I was m wondering if there is a good cleaner that I can add to my fuel?

 

Used to use SeaFoam, and have used Marvel Mystery Oil, Ethanol treatment (when I can't find E free gas). STP released a new treatment last year that I believe is easily the best. I know it's STP, but the stuff is really good. I still use the MMoil especially in my small engines.

I did an experiment for fun to see which one worked the best. Took 3 aluminum cans cut in half, put in 3 brand new bolts and 3 small cut outs of some mesh screen, then 3oz of 87RON(10% Ethanol gas), a drop of H2O (cause it get's in your carbs and contributes to varnish)-this mixture was agitated and heated (hair dryer) thoroughly and then I let it sit covered for a month. All three screens were varnished and the bolts were no longer silver and were sticky. I removed all the solution and filled with just MMoil, STP, and SeaFoam and then agitated and heated again-waited 3 days. They all came cleaner but the STP was the best, MMoil second, SeaFoam third. The varnish was basically gone with STP.

Doesn't take much in a small Motorcycle tank, a couple of ounces at most. Keep in mind though if you have any blocked passages, then nothing short of manually cleaning will work. Add in solutions won't bust through a fully clogged spot effectively if they can take any other path-they will.

 

Holy Deja Vu Batman! :lol:

http://www.xjbikes.com/Forums/viewtopic/t=36619.html

 

Ya think? It's called "fishing for answers." That's when you keep asking basically the same question over and over because you didn't like the answers you get.

This is a classic case.

And what makes it truly sad is he's been fighting with it since last April rather than take the advice given.

My patience has about run out.

 

Thank you all so so much I forgot a lot of this stuff becouse I stop working on the bike for a long time but I am going to take y'all's advice and do the valves tomorrow

 

You all will love the these are the result from my valve Check 1 in 001 ex 005 2 in 004 ex 007 3 in 000 ex 006 4 in 005 ex 006 thank you all for your help I got the shims for a junk yard for my bike

 

OK, so you've got two "dead tight" intake valves (#1 and #3.)

That in itself would have been causing all sorts of "running" issues.

Get them all in spec; re-check, and then get a compression test to be sure that no damage has been done.

Also keep in mind that even though .004" is given as the "tight" spec for intakes, .004" = .10mm. So if your .004" feeler fits tightly on #2, that one is out of spec too.

Likewise .006" for exhaust valves. .006" = .15mm, so any exhaust valve reading a nice tight .006" is also out of spec. So you really need to re-shim exhausts #1, #3 and #4 as well.

You'll probably need to go two sizes down on Intake 1 and two (or even three) sizes down on Intake 3. That one may take a couple of tries since you can't get a measurement.

You're now seeing for yourself why this is so important.

 

Yes I have had a compression test done I came back fine

 

Just finished now to start it in the morning thanks for all the help

 

Good work! Keep us posted.

 

Thanks I went for a ride today It ran great (I did not get it up to temp) what is the running temp?

 

It will need a good 12 ~ 16 miles to get fully warmed up.

 

Ok thanks