I need some guidance with my bike.

So based on what I am understanding, you mean this little brass tube that hands just higher than where the pilot jet is?


To check and see if it is blocked I should take carb cleaner and spray it into the pilot jet specifically to see if it comes out of this tube? Honestly what you say makes sense if these are clogged, but god damn this is getting old, I swear I've cleaned these out (picture is from spare carb, so that's why it's grungy looking).

I'm not kidding, I've used literally over 5 cans of carb cleaner on this carb, that's why I'm getting so tired of it xD

I guess I'll rip the carbs off the bike AGAIN and just MAKE SURE this little jet isnt blocked. Thanks.

But that still does not really answer my question too about why does the bike sputter and act super lean when "under load" under 2500 rpm UNLESS I have the pilot mixture screws out 3 1/4 turns, does this little tube run in the pilot system when the bike is running aswell, or is it just for startup?

 

Although that brass tube could be clogged (also note: there is a small air bleed hole in the side of that tube, just below where it enters the carb body, that may also be blocked), typically the problem is the small JET that is at he bottom of the carb BOWL that feeds that brass tube...…..that brass tube goes into an opening in the float BOWL, and the starter JET is at the bottom of that opening in the bowl. The brass tube sucks up the fuel that passes thru the jet, and if that jet is clogged, well...……..


Why is my engine hard to start, and using the choke makes no difference?:

Most probably, the starter jets --- which are tiny, and are down inside the carb bowl ---- are plugged up with fuel varnish or the like.


z7) Aftermarket wire BOWL STARTER JET CLEAN-OUT TOOLS. As you will quickly discover if you ever try to clean or rebuild your carbs, the tiny, non-removable starter jet that is stuck wa-a-a-y down at the bottom of a drilled passage in the carb bowl is next to impossible to clean. For one, did we mention that the jet opening is TINY? And did I also mention that it's stuck way down at the bottom of a small passageway, and basically unreachable? AND THEREFORE, NO ONE EVER REALLY EVEN ATTEMPTS TO CLEAN IT OUT? And that a clogged starter jet not only means trouble starting and idling, but that starter circuit is actually also involved in idle and off-idle performance? Well, how do you actually clean it? Even the tiniest cleaning rod in our carb passage cleaning wire sets (above) aren't small enough to fit through this starter jet (it is THE smallest jet-passage in the entire carb)...

Well, here's how you clean it: with these jet clean-out tools. Just big enough to get through the jet, but not big enough to ENLARGE the jet (that's a huge no-no), these high-speed steel STARTER JET DRILL BIT or the STARTER JET WIRE PROBE TOOL. The drill bits can be gently rotated (but never "pushed", as it will break), while the stiff pointed-tip wire probe tool can be twirled to dig through the toughest of crud. This is the only way to properly clean these starter jets.

NOTE: these are TINY drill bits, and will not chuck into a standard drill chuck. You have to use a mini pin-vise attachment or do it carefully by hand.

COMPARISON: these drill bits are a mere 1-1/2" long, and as such, will disappear below the top "plane" of the bowl as it goes down into the jet. You will have to use a pair of very slim needle-nose pliers to grip the tip of this drill bit and rotate it! The probe tools have a long piece of semi-rigid steel wire attached at the end of a hand-held "pen" stick.

The drill bits are harder to manipulate, but do a better job since they have a "cutting edge" on the tip.

The probe tools are easier to manipulate, but don't do quite as good a job since they do not have any type of "cutting edge" on the tip....but are still sharp enough to "pick" through most types of sludge and build-up in the jet.

NOTE: The 1980-81 XJ650 carb bowls should have removable bowl starter jets, which will make your life a lot easier!

http://xjbikes.com/forums/index.php?threads/43931



HCP2296 Aftermarket BOWL STARTER JET DRILL BIT, for Hitachi carb bowls used on all XJ650 (except Turbo) models and all 1981-83 XJ750 models.
$

HCP2299 Aftermarket BOWL STARTER JET DRILL BIT, for Hitachi carb bowls used on all XJ750E-II and XJ750RL models.
$

HCP12929 Aftermarket BOWL STARTER JET WIRE PROBE TOOL, for Hitachi carb bowls used on all XJ650 (except Turbo) models, all 1981-83 XJ750 models, and XJ750E-II and XJ750RL models.
$


HCP2293 Aftermarket BOWL STARTER JET DRILL BIT, for Mikuni carb bowls used on all XJ550 models, XJ650 Turbo models, all XJ700-X and XJ750-X models, and XJ900 N/FN, and F models, and Hitachi carb bowls used on XJ700 air-cooled engines.
$

HCP12927 Aftermarket BOWL STARTER JET WIRE PROBE TOOL, for Mikuni carb bowls used on all XJ550 models, XJ650 Turbo models, all XJ700-X and XJ750-X models, and XJ900 N/FN, and F models, and Hitachi carb bowls used on XJ700 air-cooled engines.
$



P.S. how do you know when your starter jet is really, truly, zestfully clean? One of two ways:

a) shine a strong penlight or mini flashlight into the bottom of the bowl, where this jet passage "intake" is located. Look through the top of the bowl down into the jet passage "outflow" passage (this is the passage that the brass suction tube in the bottom of the carb body actually fits down into). Focus your eye carefully on the jet opening and make sure it's clean. P.S. it helps to do all this while in a darkened area.........see the picture "starter-jet.jpg" on page 2 of this forum thread topic for a great image of what you want to see!:

http://xjbikes.com/forums/index.php?threads/4050


b) put the spray tip (you may have to gently shape the end of it to a fine point, see the video below) of a can of carb or brake cleaner into the intake opening of the starter jet and let rip a spray. A STEADY, FINE, POWERFUL STREAM OF FLUID WILL COME OUT OF THE OUTFLOW PASSAGE ON THE TOP OF THE CARB BOWL IF THE JET IS PERFECTLY CLEAN AND OPEN. I mean this stream will absolutely spit out a good 5-10 feet. If the stream isn't powerful and laser-like precise coming out of the jet, then the jet isn't zestfully clean.....


By the way, when using the spray-stream method of checking the jet, don't even THINK of putting your eye or face anywhere even NEAR the jet outflow path, unless you like a painful and potentially serious trip to the emergency room.

 

Oooooooh!!!! Are you talking about this?!

I did not even notice these! And no, I did not even attempt to clean them besides what overlapping cleaning me cleaning the bottom of the bowls might of done. So yeah these very well might be clogged still since I never really even knew they were there!

 

They are easy to miss, it is all part of the learning curve, I did the same until I learned about it on this forum. I bet that is the problem you don't have enough fuel for cold starting. When those are blocked when you put the choke on (which is actually an enrichment circuit) the fuel cannot be drawn into the carburettor to enrich the mixture.

 

I just got the carbs back off the bike again and sprayed the outside with carb cleaner, gonna let them dry for 10-15 minutes before bringing them in for disassembly, I've already drained the fuel bowls. Once again, wish me luck xD

 

Remember and spray the carb cleaner down the brass tube too and you should see it coming out inside the carburettor stub that goes onto the engine intake boot for each carburettor. When the jet is clear and you put the choke on and crank the engine the fuel in the bowl goes through the tiny jet and up the brass tube into the inlet stub.

 

So yeah, I'm pretty positive this is my problem. I have a super strong 8000 lumen flashlight and shined it down all the holes, I couldn't see light in ANY of them through the other end. I tried cleaning them all with fresh cans of carb cleaner and only managed to get ONE free, the rest are still blocked. I have carb cleaner sitting in the channels though and will try again in abit, or let them soak overnight. The cleaned one looks like this now.

 

I do have spare carb bowls I can use if these absolutely REFUSE to come clean, but I really want to refrain from using them because the drain screws are super stripped, I'd have to extract them which would in turn destroy the screws. I'm hoping to sell these spare carbs on here eventually to someone who may need them and would like to do as little damage as possible to the oem equipment.

 

Great and that is what I did leave them to soak you want to clear them without enlarging them. Yes those blocked jets are the culprits.

 

Light at the end of the tunnel is what you have in that photograph lol.

 

Second bowl free, it did a sort of *Pop* when it finally freed. I took the end of the small red tube and sanded it ever so slightly so it would get a perfect seal in the little hole inside the bowl, the pressure popped the junk out of the jet. 2 down two to go, their soaking still right now.

 

That is what you want a stream of carb cleaner so the fuel flows freely.

 

IT STARTED ON ITS OWN!!! COLD!!!! HAHAHAHAHAH I CAN'T STOP LAUGHING I'M SO f***ING HAPPY

 

Give it a good run to see how it is throughout the rev range.

 

Rode it for alittlebit, I put the pilot screws back to 2 1/2 but I think I'm going to have to put them back out around 2 3/4 or 3 because I'm getting the low rpm sputtering under load again. Also the clutch is slipping untill the bike is fully warmed up so that's due for a rebuild.

 

Is the clutch adjusted property? Check the cable is not slightly tight and are you using JASO oil. Car oils can cause clutch slip on motorcycles with wet clutches and synthetic oils can too. l read that on the forum somewhere. Worth checking before you replace the clutch plates. Yes open up the pilot screws to where you had them before is better l think.

 

The clutch has been slipping since I purchased the bike, and I wanted to make sure I dont end up smoking the solid metal plates between the clutch packs so it's less expensive to replace altogether. The oil I replaced that was in it is Valvoline motorcycle oil that is JASO rated for operation with wet clutch motorcycles. To replace that now I purchased triple protection diesel oil from Shell since K-Moe and others have given it raving reviews and it is JASO compatible. Should I just swap the oil first and spray the internals of the clutch pack with carb cleaner and see if that works then if it is still slipping wait till next oil change to rebuild clutch?

 

Also a note on it being slightly tight, how much travel roughly should there be from the start to the end of the movement with the little tang arm connected to the internals of the clutch? When I ride it should I set the adjustment on the handlebar to be more/less (It's an aftermarket adjustable clutch lever) and see if the slipping gets worse or gets better? There are six adjustments on it and it is currently set to the 6th setting, giving the clutch arm the most travel when being pulled.

 

I would change the oil first but if you are concerned about the steel plates might be better to change the friction plates now and use
the oil the guys recommend. That way it's sorted. There is an alignment dot on the lever the cable fits into at the clutch end of the cable and the dot aligns with a line on the clutch cover. Check that and have 4mm clearance at the clutch lever on the handlebar.

 

Oh the dot and line are shown on my 900f engine the 750 should be the same. Check the dot and line first.

 

If your going to fit new plates soak them in clean engine oil overnight before fitting them.

 

Alright, and that dot to dot picture above, is that with the clutch pulled or at rest?

 

At rest with the cable detached.

 

Any idea how to remove these rusted washer looking things to remove the black plastic from the battery housing cover?

 

A small socket should remove them if they are hexagonal bolts a socket can fit on to. Trouble is they look round in the picture. Don't have them on my bike. Someone with a 750 will tell you.

 

Their called "Internal Tooth Starlock Push On Locking Washers" and I guess their meant to be semi-permanent, every way I see to remove them involves destroying them in the process with a pick or chisel.

 

Do they look like this?

 

yes

 

This sometimes works. Spray some WD-40 or get light oil on the peg then with long nosed pliers catch the washer if you can and rotate it while pulling gently on the pliers which will tighten the grip of the washer I know but it is worth a try. Hopefully the oil and rotation of the washer will help remove it.