XJ650R carb and running issue

I was haveing a sudden hard starting issue with my XJ650R so I decided that it was time to clean the carbs. I did so and replaced the jets in the float bowl and the emolsion tube. I also found in the process that one of my idle mixture jets was missing the little o ring inside so I replaced all the mixture o rings. Washers and springs with new. I then proceeded to put the carbs back on after I did the float bowl measurement. All levels came out fine just under the split of the bowls. At this point I replaced my coils as well since they were original to the bike. After a while of running I finally had the bike running like a champ. Idle was around 1000-1100 rpms. Here is my problem. Bike is normal with correct throttle response. Acts normal with the enrichment system working. I also don’t need it start anymore but when started I use it to assist in warming up the bike. When I put it in gear after warming up it spits and hesitates like no other. If I add a little enrichment it runs like a champ but has a high idle. This will last until I get on it pulling it through 6 grand a few times running through gears. I did a carb sync in accordence with the Manual and it’s still the same. Fuel petcock is clean co blockage and runs on on and reserve. Anyone have advice.

Thanks

 

3mm +/- 1mm (.12 +/- .04 inches) is the fuel level spec
not " I did the float bowl measurement. All levels came out fine just under the split of the bowls"



t one of my idle mixture jets was missing the little o ring inside so I replaced all the mixture o rings. Maybe you just did not se it way down inside the carb

you have to set the mixture screws 2-1/2 turns from a soft bottom is where to start then color tune or check plug color and slowley adjust the mixture screws 1 dime width at a time

did you clean out the main air jetpassage that goes to the emulsion tubes?
was the washer under the jet flat so it sealed properly?

where did you buy the parts you replaced?

 

How about air leakage at intake manifolds?
Very often gasket has failed and small cracks on face of manifolds were gaskets meet.
And. When was the valve clearance checked?
And the small passage in the float bowl that the brass tube sits in?

 

These are all checked and no cracks or leaks. Valve clearance was check about 600 miles ago. Only one adjustment made to the #4 cyl. And the small holes for the erosion tube are clear and free.

 

I bought the rebuild kit from a company in AZ. I re checked the float levels and they are running at 3 mm. And yes I looked to see if the o ring was there or not. It was not. My mixtures are set a around 4 turns out. And washers were in good condition. This issues that I am having is only when the engine has a drag on it. But with the enrichment cracked open a little it goes away but with a high idle. Just took COLD compressions and they are at 125 psi.

 

Yes that is also free and clear

 

If im correct the idle screw is fuel on that model, 4 turns out is too much, hence start with no choke, wont idle hot.
Quote XJ550H. Idle screw 2.5 turns....

 

It idles just fine hot or cold. Only hesitates when in gear

 

What main and pilot jets are in there?
Airbox or pods?
Stock or ?? Exhaust?

 

Stock 40 and 120 I believe

 

And they are in the correct positions

 

120 main way too big, stock main jet on us model xj650r is 110 Canadian 112

 

No your right it is a 110

 

XJ560H I bought the rebuild kit from Alphamoto.

 

It sounds as if some of your internal pilot fuel circuit passages are clogged....this is why it runs better when you bump the enrichment on, the starter ("choke") circuit gets its fuel supply from a different source, and the use of the choke is providing the missing fuel supply needed at idle and low speeds.

 

I don’t have a colortune but I do have a laser thermometer. What should my exhaust gas temps be set at?

 

What color tune kit do I need for the 82 XJ650R?

 

A 14mm plug for colortune plug

 

Thanks!

 

It doesn’t need to be the long reach correct

 

Correct. I have the xj650r and don't need the long reach.

 

Thank you!!

 

Hello, I’m still having issues with this carb rebuild. I have bought the colortune and used it and the engine is running smoothly. But still having the same issue acts like a clogged circuit only when in gear. Does it make a difference if the fuel petcock is on pri or on? Or should it? Tried both no difference but petcock is operating normal in the in pri and res position. Just tested the valve manually. I have the stock jets installed and correct position. I am running a 4 into 1 exhaust with a straight pipe and an uni hi flow air filter. This bike ran just fine (strong) in this set for almost 10k miles. Do I need to jet up? I’m just about at the end of my limits with this rebuild. It’s been months down and is driving me crazy. Also I have cleaned all fuel passageways multiple times with crb cleaned and compressed air. SERIOUSLY STUCK!

 

It revs and maintains RPM fine under no load?

 

Just a thought have you upped the main and pilot jet for straight pipes.
A quick guess would be 114-116 main and 41-42 pilot jets.

 

Yes it revs fine with no load

 

No I have not upped the jets. It ran fine like this before I cleaned the carbs

 

There is a fuel supply issue in the carbs somewhere as chacal noted. Did you check the flow through the needle and seats? Debris could have ended up in something when you reassembled and reconnected the fuel line.

 

How would you check the flow? I have cleaned these carbs 3 times and have blown through them with compressed air as well. I also have an in line file filter as well before the carbs.

 

Activate the float and see if the air starts and stops. Just shooting air into an opening does not prove it's open in the circuit. You could be pushing debris further into the body.

 

Confused! How do I activate the float? With the carbs installed I have blown into carbs and cannot get past the float needles. This when fuel in the floats.

 

empty the bowls. turn carb upside down and air should stop. turn it right side up and it should flow. you should do this for each carb separately.

 

Is the air being supplied through the fuel line? Where do listen for the air.

 

yes, you should be able to tell if it's getting blocked or not when the floa should be closing it. it's easier to test it with the bowls off and fuel line on to make sure fuel is flowing, but it's messy.

 

Got it. Thanks. Will check back soon.

 

so after you give the bike a work out by 6k and shifting, can you come to a stop and drive away with no issues?

stumbling problem
does this happen with petcock set to on?
what happens with petcock on prime?

 

if you start the bike and drive away with out the warm up cycle does it still sputter and spit?

choke off ?

 

did you ever consider that problem is electrical?

battery, charging system?

 

I have not done that. However I did use the colortune this afternoon for my last attempt before I take the carbs back off and tuned to the Vinson blue like the manual said and in N it was fine. Then I went for a test ride and it was running well until about 2 miles into the ride it started to fall back off sputtering around 3000-3500 RPMs. And now I’m back to where I started again. But I will do the cold ride and see what it does.

 

Charging at 13.9 volts with new battery

 

Gas cap vent ball is stuck?

 

are the air jets in the right holes?

 

Aftermarket cap and no vent ball is not stck

 

Had the same thought and all jets fuel and air are in the correct position

 

i think there's a picture in a book that's wrong, don't go by that.
small air goes over large fuel

 

What your talking is under the diaphragm right

 

Do you have any pictures of the correct installion?

 

is that at 2000 rpm? that is out of spec.
also test at 3000rpm.

I am not thinking it is electrical but you should look into the low charging.

could be a fuel supply is sue.
Plugged gas cap vent
Your Gas Cap and You
could be hose or petcock
could have a bad vacuum hose leak and your petcock is not giving you the fuel flow. running on prime should give you a hint. if it runs ok on prime