carbs carbs carbs.......

I have a 1981 Yamaha 650 Maxim. It sat outside for about 2 years. I replaced the battery, Carb kits, sparkplugs, cleaned out the gas tank, installed a inline fuel filter,I also have a new starter. I cleaned the carbs to rickomatic specs located in xj chat. The carbs are clean. The problem I am having is that I have to use quickstart to start the bike. It doesn't fire when you have the choke on and it doesn't fire when its off. But it will start right up when I use quickstart. Any suggestions????

 

Sounds to me like you may have a weak spark if you need starting fluid to start it. You may want to check all the connections and test the coils. It's a place to start anyways. PD

 

After it warms up will it restart?

 

Did you spray through the Fuel Bowl Jets and probe the Siphon Tube.

Failure to Start is linked to not getting raw fuel to the top-side of the carbs.
The fuel bowl well and the siphon tube that it extends down into need to be free flowing or no gas is going up to the Enrichment Valves.

Secondly, having to add Quick Start means that the Pilot Jets might be way too lean.

How does the Bike run when you DO get it started? Does it Idle strong? Or, dows it "Hunt" for an Idle speed?

If its Hunting ... you need to bring OUT the Pilot Mixture Jets until the Engine is feeding on the Fuel and Air from the Pilot Jet adjustment.

Let us know.
PM me if I miss seeing the Thread.

 

It has a good spark to it. And it runs fine after it runs for a while. It will start by it self when it is hot. I will break the carbs down tonight to double check the siphoning tube. Any tips on cleaning the siphon tube? Anyways I will let you guys know how it turns out tomorrow.

 

Probe it with a wire cleaning tool from a Welders Tip Cleaning Set -- $4.00 Hardware Store.

Flush it with a Rubber Baby Booger Sucker (Ear Syringe) Drug Store.

Use the wire tool to probe and clean the smallest metering ports on the whole Carb. Do the end and any along the side.

Fill the Rubber Syringe with Spray Carb Cleaner and fit the "Nozzle end" right over the Siphon Tube and force the Carb Ckeaner through the Passage through the OPENED Enrichment Valve.

 

At the front of the float bowl there is a well the siphon tube sticks into. At the bottom of that well is a very tiny hole that connects the well to the main float bowl. These are frequently plugged up. My carbs looked factory new and those little buggers were stopped up. You can poke them through with a small gauge copper wire. When you spray carb cleaner through and it comes out the well and hits you in the eye you know they are open

 

The siphon tubes were clear but when I checked the float bowls the well are clogged nothing comes out of them I am going to spend the night and clear the holes and Ill let you know tomorrow! Thanks for the excellent advise! I hope this fixes the problem.

 

RickCoMatic, "Rubber Baby Bugger Sucker"? Now that's funny right there, I don't care who you are!!

 

The siphon tubes are clean I bought a welders cleaning kit as suggested. The problem I am having is with the float bowl well. I sprayed carb cleaner down in there and doesnt come out the other side so I tried to clean them out with some copper wire and I got some black gunk out of the hole. But there must still be some more in there because I cant get the carb cleaner out the other side. I used the wire,carb cleaner and air and i still cant get it clear any suggestions???

 

I used an adapter for a foot pump that inflates footballs, it fitted perfectly into the hole inside the float chamber and i blew it out after soaking in thinners overnight.

 

z7) Aftermarket wire gauge Drill Bit for Bowl Starter Jet. As you will quickly discover if you ever try to clean or rebuild your Hitachi 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 HCP950 and HCP953 carb passage cleaning 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 this tiny drill bit. Just big enough to get through the jet, but not big enough to ENLARGE the jet (that's a huge no-no), this high-speed steel bit can be gently rotated (but never "pushed", as it will break) through the toughest of crud. This is the only way to properly clean these starter jets.

NOTE: this is a TINY drill bit, and will not chuck into a standard drill chuck. You have to use a mini pin-vise attachment or do it carefully by hand...... ALSO: this drill bit is 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!

HCP2296 Starter Jet Clean-Out Drill Bit
$ 11.95


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....

b) put the spray tip (you may have to gently shape the end of it to a fine point) 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.....

BTW, 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.

http://xjbikes.com/Forums/viewtopic/t=2 ... t=180.html

 

I finally got the holes cleared I had to use a drain cleaner to break up the gunk then carb cleaner shot through it like a charm dont worry I used a full can of carb cleaner to make sure they were properly cleaned. It fired up like a charm I really apperciate the advice I would have been lost for months wondering why it wouldnt start cold.

P.S. Is there a easy way to put the boots back on or are they always a pain in the butt?lol.

 

Microwave them in a really moist towel for 45-seconds to a minute ... they'll be nice and soft and pliable.

 

yeah I had to use a heat gun. Too hot to the touch! lol Thanks again for all of the helpful advice!!!

 

I heat them up in the Microwave.

I also put a dab of waterproof grease in the Locating Channel that splits the the front of the airbox where they stick out from.

Plus, I sanded the holes in the front of the airbox with 400 sandpaper taking any sharp edge off and rounding-off the corners so the Boot rotates very easily upon reinstalling.
More of a burnish than taking any material off.
Just being sure that I have a smooth surface to let those Boots rotate in.

 

Is there a carb rebuild kit for '81 650 carbs? I've found an extensive post where iit appears you can buy individual parts (it also has some terrific tips accompanying it), but I haven't found an actual "kit" of the most frequently replaced parts.

Also I'd like to switch the carbs to the individual pods, since the air cleaner is shot anyway. Any suggestions what jets to switch to, when I'm in there cleaning? Is there a jet kit or do they need to be purchased individually? Thanks.

 

Hey Jim.......there is no "complete" carb rebuild kit available, since the parts that are needed vary depending on your individual carb and situation/budget. But as a start, you should get one of these (well, four of them, really!):

nn) Aftermarket Hitachi Carb Lower End Standard Rebuild Kit---contains the float needle with retainer clip, float valve brass screw-in seat, a fiber seat washer, idle mixture screw block-off cap, and an aftermarket bowl gasket. The float needle seat does NOT include the filter screen. NOTE: the float Needle that comes with this set is approximately the same height as a factory Yamaha needle, and it may not be necessary to re-adjust the float level height after installation.


For all XJ650 (except Turbo), all XJ750, and all XJ700 (except "X") models:

HCP1 aftermarket Hitachi Carb Lower End Rebuild Kit, single:
$ 19.00

HCP1SET4 aftermarket Hitachi Carb Lower End Rebuild Kit, set of 4:
$ 69.00



fs2) Aftermarket Hitachi Carb Lower End Deluxe Rebuild Kit---contains the float needle with retainer clip, float valve brass screw-in seat, a metal seat washer, and a factory bowl gasket. The float needle seat DOES include the filter screen. NOTE: the float Needle that comes with this set is approximately 1mm taller than the factory Yamaha needle, and will require that you re-adjust the float level height after installation.


For all XJ650 (except Turbo), all XJ750, and all XJ700 (except "X") models:

HCP2776 aftermarket Hitachi Carb Lower End Rebuild Kit, single:
$ 23.00

HCP2776SET4 aftermarket Hitachi Carb Lower End Rebuild Kit, set of 4:
$ 82.00


and then probably the idle mixture screw pieces:


ddd) Aftermarket Hitachi Idle Mixture Screw O-Ring.....a "must-replace" item when rebuilding your carbs. Made of long-lasting, fuel-resistant Buna-N material.

HCP895 Aftermarket Hitachi idle mixture screw O-ring, each:
$ 1.00

HCP895SET4 Aftermarket Hitachi idle mixture screw O-rings, set of 4:
$ 3.00


eee) Aftermarket Hitachi Idle Mixture Screw o-Ring WASHER.....also a "must-replace" item when rebuilding your carbs. Made of long-lasting, fuel- and water-resistant 18-8 stainless steel material.

HCP896 Aftermarket Hitachi idle mixture screw o-ring Washer, each:
$ 1.50

HCP896SET4 Aftermarket Hitachi idle mixture screw o-ring Washers, set of 4:
$ 5.00



ims6) Aftermarket carb idle mixture screw TENSION SPRING, brand new reproductions exactly replace damaged, rusted, or missing originals. High-strength carbon-steel coil springs have a baked yellow-zinc plating as original.

HCP6573 Aftermarket reproduction idle mixture screw Tension Spring, fits all Hitachi HSC32 and HSC33 model carbs as used on all XJ650 (except Turbo), XJ700 non-X, and all XJ750 models, each:
$ 3.50

HCP6573SET4 Aftermarket reproduction idle mixture screw Tension Spring, fits all Hitachi HSC32 and HSC33 model carbs as used on all XJ650 (except Turbo), XJ700 non-X, and all XJ750 models, set of 4:
$ 10.95



and if you're going to do a complete job, you'll need the throttle shaft seals, the butterfly screws, and fuel connector pipe o-rings:

aaa) Aftermarket Hitachi HSC32/33 series carb Throttle Shaft V-Seal (sometimes called an "O-Ring", but it's not!)...these are the seals on the outside of the carb body that the throttle shaft passes through. Uses 2 per carb, BUT......without taking the carbs apart from the rack, the only ones you can replace are the outer seals on the #1 and the #4 carbs. Unlike the QR-series "o-rings" that many people recommend using---AND WHICH DO NOT FIT PROPERLY---these "V-Seals" do have the correct O.D., I.D., and thickness to fit both the throttle shaft and the carb shaft seal bore recess correctly. Although originally Hitachi carbs used a licorice-like "valve packing material" to seal the shaft to the carb body, such material is not generally available anymore, dries out easily, and thus leaks rather quickly. These V-seals are a superior sealing solution versus any other product out there!


HCP38B Aftermarket Hitachi throttle shaft V-seal, single:
$ 3.75

HCP38BSET2 Aftermarket Hitachi throttle shaft V-seal, pair:
$ 7.00

HCP38BSET8 Aftermarket Hitachi throttle shaft V-seal, set of 8:
$ 25.00




v5) Aftermarket Hitachi throttle Butterfly Valve Mounting Screw. Each round aluminum butterfly "valve" is held to the steel throttle shaft via two tiny phillips head screws. The throttle shaft has self-locking threads which makes the removal of these screws both a chore and usually results in a buggered phillips head slot. These replacement screwscome in a variety of materials and drive styles. Use 2 per carb, 8 per entire carb rack.

HCP1347 aftermarket Hitachi butterfly valve retaining screw, pan-head standard alloy steel screw with a phillips-drive, each:
$ 1.00

HCP1347SET2 aftermarket Hitachi butterfly valve retaining screw, pan-head standard alloy steel screw with a phillips-drive, set of 2:
$ 1.75

HCP1347SET8 aftermarket Hitachi butterfly valve retaining screw, pan-head standard alloy steel screw with a phillips-drive, set of 8:
$ 5.00



HCP1348 aftermarket Hitachi butterfly valve retaining screw, pan head 18-8 stainless steel screw with a phillips-drive, each:
$ 1.50

HCP1348SET2 aftermarket Hitachi butterfly valve retaining screw, pan head 18-8 stainless steel screw with a phillips-drive, set of 2:
$ 2.75

HCP1348SET8 aftermarket Hitachi butterfly valve retaining screw, pan head 18-8 stainless steel screw with a phillips-drive, set of 8:
$ 10.00



HCP1349 aftermarket Hitachi butterfly valve retaining screw, low-profile hex-drive allen-head screw made from 18-8 stainless steel, each:
$ 1.50

HCP1349SET2 aftermarket Hitachi butterfly valve retaining screw, low-profile hex-drive allen-head screw made from 18-8 stainless steel, set of 2:
$ 2.75

HCP1349SET8 aftermarket Hitachi butterfly valve retaining screw, low-profile hex-drive allen-head screw made from 18-8 stainless steel, set of 8:
$ 10.00



HCP2561 aftermarket Hitachi butterfly valve retaining screw, low-profile hex-drive button-head screw made from 18-8 stainless steel, each:
$ 1.00

HCP2561SET2 aftermarket Hitachi butterfly valve retaining screw, low-profile hex-drive button-head screw made from 18-8 stainless steel, set of 2:
$ 1.75

HCP2561SET8 aftermarket Hitachi butterfly valve retaining screw, low-profile hex-drive button-head screw made from 18-8 stainless steel, set of 8:
$ 5.00




mmm1) OEM and Aftermarket Hitachi fuel rail Connector Pipe O-RING.....all fours carbs share a common fuel supply, and this fuel supply is distributed to each carb via a brass or aluminum tube that connects one carb to another. These tubes fits into a machined bores in the carb base, and the tubes are sealed in their bores with these rubber o-rings. NOTE: original seals were "D-rings" rather than "O-rings", but are now serviced only as o-rings (both OEM and replacements), but are the correct shape and firmness to provide a leak-proof fit. You will only be able to access these seals if you break the carbs out of their rack! (and if you do break the rack, you need to replace these seals). Aftermarket seals comes in your choice of either a lower-cost Buna-N material, or a longer-life Viton material. Either one will work just fine and last until the next time you take your carbs apart!

The viton material is much harder than the Buna-N material and the use of the viton seals requires quite a bit of effort to install the connector tube into the carb fuel port bores!

- Use 2 seals per tube, or a total of 6 seals per entire carb rack, for HSC32 series carbs (XJ650 except Turbo, XJ750 all).

- Use 2 seals per tube, or a total of 10 seals per entire carb rack, for HSC33 series carbs (all XJ700 non-X models).


HCP92 OEM Hitachi fuel line Tube O-Ring, each:
$ 1.50

HCP92SET6 OEM Hitachi fuel line Tube O-Ring, set of 6:
$ 7.50

HCP92SET10 OEM Hitachi fuel line Tube O-Ring, set of 10:
$ 9.00


HCP2421SET2 Aftermarket Hitachi Buna-N material fuel line Tube O-Ring, pair:
$ 2.00

HCP2421SET6 Aftermarket Hitachi Buna-N material fuel line Tube O-Ring, set of 6:
$ 4.00

HCP2421SET10 Aftermarket Hitachi Buna-N material fuel line Tube O-Ring, set of 10:
$ 6.50


HCP2420SET2 Aftermarket Hitachi Viton material fuel line Tube O-Ring, pair:
$ 2.50

HCP2420SET6 Aftermarket Hitachi Viton material fuel line Tube O-Ring, set of 6:
$ 6.00

HCP2420SET10 Aftermarket Hitachi Viton material fuel line Tube O-Ring, set of 10:
$ 8.50



Beyond these pieces, there's lots of little hardware/fasteners that you might want to replace, as well as the special tools needed to do the job. Same for the large fuel jets. All of these items (and more!) are listed over at:

http://www.xjbikes.com/Forums/viewtopic ... t=180.html

 

Great. Just what I was looking for. I'll pull the carbs and see if I need to order everything or just start with the lower ends and some other stuff to start. A couple more questions:
1- How do I order thiis stuff?
2- what cleaning solution should I use for the carbs? Should I soak the whole body in somethiing or just spray passageways with Gumout (which I read somewhere here not to use on neoprene items as it will degrade them).

Anymore advice would be appreciated as I've searched through the archives but I'm having limited success gettiing specific iitems. (I'm still looking for jet suggestions)
Thanks.

 

Hey Jim, just send me a PM or an e-mail to info@xj4ever.com with the list of what items you need and I'll provide you with complete ordering and payment instructions.

As far as cleaning the carbs, brake/carb cleaner (spray) works great, or carb dip if you're going to be taking the rack apart.

Jet instructions:

Here is the info regarding jetting that I found:

1 jet size for custom 4 into 2 exhaust

2 jet sizes for 4 into 1 exhaust

1 jet size for K&N filter (single inside airbox)

1 jet size for drilling out the bottom of the airbox

2 jet sizes for both single K&N and drilled airbox

2 jet sizes for individual filters

2 jet sizes for no muffler (open header)

1 pilot jet size for every 3 main jet size increase

Add up all the jet size increases and subtract one. (Remember
they go in steps of 2.0 for each jet size)

Under a mismatch condition, like individual filters and stock
exhaust or 4 into 1 header with stock filter and air box, subtract
an additional 1 jet size.

Check plug color often, sync carbs after each jet change,
make sure the floats are set correctly, and seriously consider
purchasing a Color Tune.

Make sure your carbs are in perfect working order before
making jet changes.

Additional info: Decrease main jet size one step per
2000' above sea level. Decrease pilot jet every 6000'
above sea level.


http://hiredgoon.x10hosting.com/JetCalc/jetcalc.html

 

LOL For the last couple of days my bike has started great but yesterday it was doing the same thing like it wasnt getting gas. So does that mean that those wells are clogged again.? How dow knock that stuff out I have cleaned my crabs over and over and have an inline fuel filter.???

 

Do you have a vacum petcock? May be a problem with that...

The other thing you could do is Seafoam

 

If you are confident that the Carbs are CLEAN ... the issue could be elsewhere.

First. The Starter Jets and Fuel Bowls.

You know the Metering Ports at the bottom of the Fuel Bowls need to be open to supply Fuel to the Starter Jet Well. Then, there's the Brass Siphon Tube that extends down into that Well.

That Brass Tube needs to be "Probed" with a cleaning too.
Plus, there might be additional Ports on the side of that Tube.

The Tube is the beginning of the Enrichment Circuit Passage.
Flush the passage with the Enrichment Valve OPEN.
You can force Carb Cleaner through there by filling a Rubber Ear Syringe with Carb Spray and fitting the nozzle down over the Tube and squeezing the bulb.

Lets say that the Enrichment Circuit is clean; too.

Then, your problem is likely to be "Tuning"

I don't know if you are Rich or Lean. Both conditions will contribute to hard starting.
The Pilot Mixtures are "Precise". That's why they have ultra-fine thread on the Screw Body.

Those Mixtures need to be within the window of:
Providing enough Fuel to aid Starting
Sustaining Idle
Adding just enough more Fuel, allowing for a "Rich-enough" Mixture, for the brief on-rush of AIR, momentarily preceding the Main Jet Flow coming through the Intake at just off-idle, to maintain power before the transition to Main Jet Fuel takes plaace.

Just enough.
Too little and there a performance gap.
Too much and there's another performance gap.

Backfire or Bogging-down will occur.

I think you have to get your Pilot Jets and Start Circuit Dialed-in.

Buy, Borrow or Rent a ColorTune Plug and get within the narrow spectrum of correct Air~Fuel Ratio and become a Tweaker, so that after you have Colortuned the Rack -- across the board -- you can then deal with each Cylinder ... individually ... and adjust the Screw for Rich or Lean based on how the Plug is colored from the Combustion.

 

Yeah I went throught the brass tube and the enrichment circuit. Now about the tuning that could be my problem I didnt know it was related to starting. Im sorry Im ignorent.lol The Pilot mixture screws were way out of wack. This was how many turns out they were. from left to right
0,4,5,5 1/2 from previous owner it didnt want to run at all. I fixed that to all of the to 2 1/2 turns out I figured that would be the norm for them I actually have a color tune on order and was going to dial it in it just hasnt got here yet. Thankyou
Joshua

 

As Chacal mentioned about the starter jet being teeny tiny, I used the wire pulled out of my steel brush which works perfect for cleaning the jets out. The welding tip cleaners work great also.

 

Yeah I cleaned it with a welding tip cleaner. It worked really well.

 

Two and a half turns out from bottom might be just a tad Lean.
Depends on what happens bike to bike.

If the bike is idling really nice ... leave it.
If it a little unsteady ... take them to a couple degrees beyond 2-3/4.
Between 2-3/4 and 3 ... but, not quite 3.

If the idle is steady ... leave it like that until you can ColorTune.
See how it responds when you give it some open throttle.

It should be a seamless acceleration.
If it Coughs or backfires further adjustments are going to be needed.

The question is which ones nd how much.
The definitive answer will show-up when you colortune.

But, until you Colortune you can set the Idle "By Ear"
S..l..o..w..l..y turn the Screw on a Cylinder and listen to the Idle.

IF the Idle improves ... continue OUT until thehre is NO more improvement.
S..l..o..w..l..y continue OUT until that Cylinder becomes too Rich and begins to misfire.
At that point ... turn the Screw back in -- S..l..o..w..l..y until the Idle is restored.
This is adjusted for Idle ... and MAY be too RICH.

Adjust the remainder of the rack in a similar fashion.
Check the throttle response.

If its bogging-out ... turn your Screws ALL IN the width of a Dime.
Test throttle.
OK ... Leave it.
Bogging-out:
IN another width of a Dime (2 Degrees) -- Just about not moving it but a budge in the Lean direction ...
A Budge.
Eyelash.

"Tweak"
You're a Tweaker; Now ... get it right!~

 

It runs pretty well right now it just doesnt want to start. I tried it again today and it was getting gas but it took a couple of minutes to get it running. Just waiting for the color tune! Until then I'll see if I get it any closer. Thanks Rick

 

Does this advice also apply to the Seca 550 with Mikunis?