what to do to prevent having to clean out carbs?

First off, Ive been reading these forums for the past 3 days.
Very informative and I'd like to thank everyone who has contributed.

'82 XJ650Rj 23,456

There are actually two questions I'd want to ask.
It looks like I will have to do the dreaded carb cleaning.
If this has to be done what measures can I take to make sure I don't have to do it again?
Installing an inline filter and gas stabilizer are a given.
Second, I want to tell you my situation and maybe get some input as to a cure before I take the leap into carbs.

The bike was garage stored for 2 years while I was away.
In January I siphoned all the gas out and replaced it with 3 gallons of new fuel, installed new battery.
A tiny bit of choke and she fired right up, as always.
I road the bike 5,6 times illegaly during the winter, 10-15 minute jaunts.
It always pulled hard with a lot of snap.
Having sat for two years I took it to the shop in preperation for riding this spring.
They did a service, flushed the brakes, changed the fork oil, adjusted the valves.
I had asked them to sinc the carbs but was told they were fine.
"The bike idled perfect with good throttle responce", great saved me 45 dollars.

Brought the bike home, 10 minute ride.
Two days later it started right up but after warming up 5 minutes it died.
It was a little hard to get going agian but it fired and I rode 30-40 miles.
Filled the tank.
I stopped three times on this trip each time it was harder to start, always having to give it throttle to start.

Two days later a little choke turned right over.
Let it warm up, when I gave it gas it died.
It would not restart no matter what I did until, I held the throttle all the way open and cranked on it.
Then it finally caught and slowly built RPMs.
When it started to climb up quickly past 5000 I let off only to have it die again.
It would only start with the throttle all th way open, this time it would not pick up it just stayed a 1500, shut it down.

Next morning a little choke first try and it started right up.
Decided that it needed to be run and cleaned out.
I let it warm up 4-5 minutes and took off trying to keep the RPMs up so as not to stall, which it wanted to do.
It would accelerate pretty good until it got to 5000 then it would start breaking up and sputtering.
when I reach the top of the hill and had to slow to turn around it died.
I tried bump starting it all the way down the hill to no avail.
When bump starting I turned the key on and off and you could hear the difference.

Next morning pulled the fuel line off the petcock and attached a hose I ran into a jar.
I started the bike and had good solid flow in the ON, PRI and RES postions.
Filled the quart jar in 15-20 seconds.
The fuel looked clean, no particules in it.
Popped the gas cap, a little choke and fired it up.
It semed to take the gas much better, I revved it up a smile came to my face, could it be that simple?
No
After about 5-6 minutes it started to bog down at anything under 3000.
Tried to run it around the house but it still bogged down at low RPM
After a few more minutes it just didn't want to run at all.

Went to talk to the mechanic.
He said more then likely some kind of crap had gotten in the carbs and They would have to be cleaned.
I said but the gas is clean and I've got good flow.
He explained that after the bike sits that long an ash forms in the bottom of the float bowl.
When I rode the bike it stirred it up, pulling it into the jets.
He also said it sounded like the plugs are fouling
Which could be caused by water in the gas or crap in the carb.
He said I may have burned it out by now and the plugs are just fauled.
He suggested opening the drian screw in the bowl and checking for water trapped, as it is heavier then gas and could be trapped.
Those screws have never been out, I didn't even attempt pulling them(I see theres a how to on this specif subject).
So my last effort today will be to replace the spark plugs and hope that what ever it was is gone.
If not I will take it back as they said they would look at it and tell me what is wrong.

A little long winded but I wanted people to have accurate info.
If you have any Ideas on what is going on thank you.
And please if there is anyway to avoid this again fill me in.


I know it's going to be the carbs.
Isn't someones sig "It's the carbs it's always the carbs!"
:lol:

 

I put an inline filter on my fuel hose. After it gets full of crap i just change it out.

 

The issue with the gas is that it varnishes. This varnish restricts passages - the smaller the passage the more restrictive it is.

The fresh gas was a good start - but I have heard of this happening more than once.

It seems as if some of the varnish in the carbs has been broken/washed free by riding the bike and has got stuck in the smallest passages - the starting/idle ones.

The fuel filter prevents crap from the gas tank making it to the carbs, but it can't prevent crap that has formed in the carbs moving.

A second equally possible event is that you didn't have a fuel filter - and that riding the bike has dislodged crap in the tank, which again has lodged itself in the starting/idle circuit... pilots

Anyhow - it does sound like you are getting towards needing to do a carb clean. Yours could be a simple process of just targeting the smallest passages, but while you have it open you may as well keep going.

Just my armchair from a-far guess

 

If you're storing the bike for less than 6-7 months, Sta-Bil or Seafoam can be added to the gas to keep it from varnishing. Once you add some, you have to run the bike a bit to get the mixture through the carbs.

Don't let the carbs scare you.. they're really not that bad. A cleaning walkthrough (in the FAQ suggestions) and a couple of Zappa's albums is all you need. I was listening to Thing-Fish when I did my 550's carbs :mrgreen:

 

There is no way to put off cleaning the carbs so you better get used to it.
I have to clean mine twice a year even though I ride all year round.

 

Really Steve?

I have never had problems with either the CBR or Maxim carbs. Cold weather storage helps, as does stabil... Heat makes gas go bad faster so that might be the issue.

 

Yeah man... get in there and get dirty... it's really not that bad once you start.. I was a virgin till I joined xjbikes.. now I see all the cool kids are doing it

 

ya just take it slow and be neat... you'll find out its really not a big thing... other helpful things are located in the link on my sig... best wishes

 

Yep come winter it'll be my turn to pop my carb cherry. Looking forward to it.

 

Thanks to all who responded.
Purchased the inline filter from the FAQ forum.
The seafoam, stabil, idea is great as It should never sit more the 5 months again.
@ Stereomind, I've rebuilt 3 car carbs succesfully.
I guess the fact that there's 4 connected and I've never done a bike before makes me a little nervous.
I've read the walk through.
:?
Frank will definitely get you there, that's for sure.
I see Zappa plays Zappa for the 3rd time Aug 5th.

How long should I plan on my first attempt taking?
10 hours, 20 hours

Thanks again, to all here

 

Well the carbs are off the bike.
I have never seen such a mess, it's a wonder it even started.
The slides were so corroded I thought they had fused to the guide.
I finaly got them out and took them to my local shop to see if I needed new or if they were salvageable.
Shop said use some fine emery cloth and I should be OK.
Took alot of time and effort but they cleaned up nice.
Am still cleaning but just about ready to reassemble.
I'll just keep plugging at this until it's done.

Shop said if I'm going to keep the bike for life I should try and find the diaphram, slide replacement kit before they don't exist, but I should be fine for the next 50-60,000 miles
.

 

Shop gave you some good advice!

If you took the carbs apart from the rack, I hope you replaced the throttle shaft seals!!!!

Carbs on cars are like "the wide open spaces" compared to these little boogers.........

 

Thanks for the heads up Chacal

 

So carbs back on the bike and about 300 miles on the odometer since.
The bike runs very well, pop it open and it squats and gets.
I've been trying to decide if the minor bogging I have is a 650 trying to move 250 lbs or if I don't have it dialed in right.
Most bogging is below 3K, 1st gear you don't notice to much because a minor twist and you're past 3K screaming for 9.5K.
2nd gear you notice it a little more, but again you're past 3K so quickly not really an issue.
3rd gear is wear you feel the bike working.
If you start below 3K in 3rd and punch it, it doesn't shit and get, it more, slowly pulls hard 'till you get to about 6K then it takes off.
When down shifting there is some pop from the exhaust, thought it was just the 4 into 1 pipe.
After reading abit I fear I maybe hazardously lean.
Idles at 1200rpm really smooth.

I've read alot here and I think I'm really close to having this perfect.
After finding threads about plug readings I pulled the plugs and to my suprise I found all lean.
#1 plug had the very slightest of a brown streak right at the top of the porcelin and only on one side of the plug.
2,3 and 4 were white like new, no color at all.
This is what the plugs should look like maybe a little lighter correct?

So I'm thinking that I need to do the fine tuning.
I hate messing with stuff that works already. :roll:
I've searched but no one seems to have all the info in one place.

I want to run the bike till hot, then read the plugs.
Do I have to use the kill switch to stop the motor?
My bike running lean I want to ever so slightly turn the pilot screw to add fuel, make it richer correct?
Run it around the block, less then a mile, more then a mile?
Read the plugs again.
Repeat until the correct shade of tan is achieved.
If I turn the pilot screw counter clockwise this will make it richer correct?
If I'm missing something, diagnosing this wrong, let me know.
Thanks.

 

I plan on doing the same thing I do with my snowmobile. Clean the carbs every pre-season within a month before I plan to ride. I stabil and fog it but just for piece of mind I go through the carbs every single year. Maybe I am just different tho I enjoy tinkering in the garage and knowing whats going on with my things. After all in March in Mi. It is usually gettin pretty sloppy for sleds and not yet ready for the bike so there is no hurry to get it done go out there with a friend the radio and some beers and go after it.

 

Glad you got it running again !

I would not use that emery cloth on the slides. Clean them with some good carb cleaner by wiping it on, keepin it off of the rubber diaphram. I would use a 2000 wet/dry cloth in the slide bore to clean it up with some aluminum polish and do a drop test on the slide in the bore when finished. When you have the slides out and remove the main jet, did you remove the emulsion tube and clean it ? If not. that could be your hesitation on the low end. Only thing I would add if your going to store it for any length of time, Drain the carbs. Hopefully you got the drain screws loose when you cleaned them as you'll also need them loose to check the float levels to ensure the height is correct.

 

That's a good question ! What kind of riding is everyone doing before reading the plugs? A "plug chop" is accelerating hard 0 - to - 80 then kill the engine and coast into a parking lot, bringing the plug wrench with you. Drag racers do that. What I do is a 20 mile hi-way ride, with 5 blocks of low speed riding at the end.

My plugs are whiter than those pictured; just slightly tan.
A reddish color is an additive in gas, so switch brands and re-test.
The red color throws off the tan color.

 

Hound, you're on the right track! But, to really get your bike purring, you should listen to the live version of Zappa's "The Muffin Man" while cleaning and tuning your bike, as well as keeping these things in mind (this was written in response to a similar, but different question, but all the main thoughts still apply):


"CARB" SYNCHING AND OTHER FANCIFUL MYTHS


Q: I know that you adjust the valves first (valve cover gasket also on the next order) but what is the sequence for the Colortune and Carbtune?

A: Well, it depends on whether you've "rebuilt" the carbs or not....kinda depends. If you've had the carbs off the bike, then the first step is to "bench synch" them, which means getting the butterflies "pretty close" to being all equal in terms of how much they are open at their fully closed (idle) position (the butterflies never actually "fully, completely" close, they always remain open a tiny amount, otherwise the bike wouldn't get any fuel-air mixture in, and thus wouldn't run). "Synching" on a bench means adjusting the synch screws (there's only three of them, the #3 carb doesn't have one because all of the other carbs are synched in relation to #3) while eyeballing the other throttle butterflies, and getting them "close enough" to allow the engine to start and run.

If you haven't had the carbs off the bike and apart, then you go directly to:

Then, you do a "real" synch, using the Carbtune or other such device. Again, what you're doing is manipulating the synch screws (3) in order to adjust each cylinder's output to be equal. On the "bench synch", all you're trying to do is get each butterfly valve to be equal with all others----like I said, close enough to allow the bike to start and run.

"Real" synching means you are going to be adjusting the positions of the butterflies (via those synch screws) so that EACH CYLINDER PULLS AN EQUAL AMOUNT OF VACUUM----if each cylinder pulls the same amount of vacuum (which is all a manometer is....a fancy, 4-in-1 calibrated vacuum gauge), then each cylinder is "pulling an equal load" as far as it's torque/horsepower output----hence each cylinder is "in synch" with each other cylinder, which results in a much smoother idle and better overall performance (less wear and tear).

Quite a number of factors affect how much power each INDIVIDUAL cylinder is producing......the valve adjustment of that cylinder. The piston ring seal of that one cylinder. The carb adjustment of that one cylinder. Etc. Etc. So the "real" synch that you perform with the Carbtune takes all of the those factors into account, and allows you to "compensate" for all those factors by opening or closing throttle butterflies valves enough to get each INDIVIDUAL cylinder producing the same power output---with the "power output" actually being measured by the amount of vacuum that the cylinder draws. Once each cylinder is adjusted so that it produces the same amount of vacuum draw as all the other cylinders, then your carbs are "in synch" (actually, your entire engine is "in synch", but since you do it via an adjustment to the throttle valves, it became know as a "carb synch", which is really incorrect termnology!).

Note that what you're really doing is bringing all the cylinders DOWN to the performance/power output level of the worst cylinder. Although this may seem like a dumb thing to do, it's the only way to synch the power output of each cylinder, and is a "lesser evil" type of thing as it relates to the overall performance of the engine.

Now, in regards to the "idle mixture screws", people throw around many terms that all refer to the same thing: idle screws, idle mixture screws, pilot mixture screws----all the same. The idle mixture setting is the ONLY adjustable setting on these carbs (besides the idle SPEED, which you do with the big knurled-knob screw that is dead center, on the bottom of the carb rack), and since this idle mixture setting goes through the PILOT FUEL CIRCUIT (which really means the "idle and low speed fuel-air mixture circuit"), well, there's why they call it a "pilot mixture screw" as well as an "idle screw" or an "idle mixture screw".

Words---they really get in the way sometimes!


NOW, SORTA WRAPPING THIS ALL UP:

Since the synchronization of each cylinder's output to a level of equality is the crucial goal, and since the synch is done at idle speeds (or, at least, at engine speeds in which the pilot fuel circuit is primarily the one that is active), and since the only fuel/air adjustment that can be done is via the idle mixture screw, then adjusting this screw WILL result in a difference in the fuel-air mixture in that cylinder, and thus will change the power output of that cylinder, and thus will change the synch of the entire engine (see where I'm heading?).

So here's what you do:

a) adjust the valves first. An out-of-adjustment valve---intake or exhaust---will reduce the power output of the cylinder that it is associated with, AND RECALL, "synching" means running ALL the cylinders DOWN in performance to the "lowest performing cylinder" in order to get them all producing equal power. This is why you adjust the valve clearnaces first, to get any performance issues associated with too tight or too loose valves "out of the equation".

b) Synch the carbs on the bike. This will be a "rough synch".

c) Adjust one idle mixture screw at a time to get that "bunsen blue" coloration. Once obtained on a cylinder, remove the colortune, put a sparkplug back in, and re-synch.

d) Go to the next cylinder, colortune it. Then replace the colortune plug with a real plug, re-synch the bike. (by the way, you leave the Carbtune Synch Gauge hooked up all during this procedure----as well as leaving the petcock on PRIME, since the petcock's vacuum source is now hooked up to the Carbtune).

e) Do this for all the cylinders, one at a time.

f) If you're aggressive and excited about the whole procedure, then go back and do the colortune #1/synch/colortune #2/synch/etc. routine again. By now you'll have that puppy purring.

g) If your fiddling with the idle mixture screws doesn't get the color of the flame in the colortune window to change AT ALL, then you're carbs are dirty internally, and, like or not, they need to be cleaned. Completely. Thoroughly. Zestfully cleaned.

Okay, all of that sounds like a lot, but once the gauges are set up on the carbs then it doesn't take long. Plus going from one cylinder to the other allows the little colortune plug some "downtime" in between cylinders to cool down.....and I'll also add, that during this downtime, you should also remove the YICS blanking tool from the passage, and allow it to cool down too (if the rubber seals get too hot they'll melt in there---and then you have a huge mess on your hands!) Wear gloves, trust me!!!

Oh, I forgot to add, that before you start the whole procedure you insert the YICS passage block-off tool into the chamber, and leave it in the entire time. At then end of the entire procedure, of course, you remove the tool, and then if you want to go one more round of COLORTUNE ONLY of each cylinder, go ahead, it shouldn't change things enough but may get you a final little bit of tuning accomplished.....but not enough to throw off the synch that you've just accomplished. And remember...a little rich on the mixture is much better than a little lean!

Then you go out and ride, and inspect your plugs after 50 miles or so. They should be a nice, very light tan color. Bright white = too lean....and that's a Very Bad Thing, especially on air cooled engine. It's also a shame and a devil's temptation, as engines produce more power when they run just a hair lean....such is the trade-offs of life, right? And dark brown or black = too rich or oil burning problems.


ABOUT VALVE SHIMS:

I carry all sizes of new shims, both aftermarket and OEM, in stock at all times, and given that you'll only find that two or three need replacing during a typical service, it really is rather inexpensive to do.

With used shims, you take the risk that the indicated size on the shim is still the actual size........although shims are "hardened steel", the hardening process only extend a few microns down into the surface of the shim, and once that hardened surface is breached, the shims wear rather significantly.

Thus each used shim must be miked (measured with an accurate, verified micrometer or other such precision measuring device) to determine it's "real" thickness as opposed to its indicated thickness, or otherwise you risk installing a used shim, thinking it will give you the proper clearance, and finding out (assuming you re-measure the clearances after replacement, as the service manual and common sense dictate!) that the (for example) 270 shim that your original calulations said you needed, and the 270 used shim that you installed, STILL doesn't give you the specified proper clearance............

Now, suppose you just throw the used 270 shim in, and don't bother to re-measure the clearance? Well, it might be right on the money. Or it just might not, in which case you'll STILL be operating with out-of-spec clearances, and even more important, without all of your valves being in spec---and here's the key point which you should ignore only if you wish to have continual, ongoing-forever performance problems--- ALL of your carb work (rebuilding/cleaning/adjustment, synchornization and tuning) is mostly for naught, because you can't "synch" an engine when it is out of adjustment......and while we're on that subject, let me add that the terminology used is fully incorrect: you don't "synch" carbs, you "synch" the entire engine, one cylinder at a a time, VIA THE ADJUSTMENT OF THE CARB BUTTERFLY POSTIONING. Understanding that concept is vital to understanding why it is so important to maintain proper valve clearances.


TO RE-CAP:

- you want to be able to have the power output of each cylinder to be equal in order to get the maximum performance, smoothness, and life expectancy from your engine.

- power output of each cylinder is strongly affected by a number of factors, with one of the main user-adjustable features and service parameters being the valve clearances.

- power output from each individual cylinder is measured via the vacuum draw of each cylinder on a mamometer, also known as a vacuum guage. The stronger the vacuum draw, the stronger the power output.

- in order to bring each cylinder's power output into equality---AND HERE"S THE IMPORTANT POINT TO PONDER----you have to DECREASE the power output of the best cylinder(s) to that of the weakest cylinder in order to get all cylinder's power output equal (meaning in "synch" with each other).

- you reduce a cylinders output in a one of two ways: adjust the valves on a cylinder to not open as much as on other cylinders, or open much more than other cylinders (those two methods are obtained by allowing the valve shim clearances to be out of spec), or you crank the butterfly closed on a cylinder. A third method would involve messing sufficiently with the fuel mixtures, via the idle mixture screw, to choke a good cylinder(s) output down to the lowest output cylinder, although that has significant other ramifications of doing so.

In theory and practice, you could actually "synch" an engine simply by adjusting valve clearances on individual cylinders (while leaving the butterfly shaft openings all the same) until each cylinder's vacuum draw, and thus power output, were equal. NOTICE: leave the throttle shaft opening THE SAME, and adjust the valve clearances. OR, you can do it the way the factory recommends: FIX the valve shim cleaances to proper specifications---in essence, thus leaving the valve clearance "the same"----and ADJUST the butterfly openings to compensate.

Valve shim clearance checks and adjustments are probably THE most overlooked aspect of maintenance on these engines, mainly because it's thought of being such a pain in the butt to do, and if your clearances are out of spec, you then have to wait for replacement shims to be delivered to you. That's why I carry all sizes in stock, and can normally ship the same day, via priority mail or express mail or whatever service level you desire and wish to pay for.

In reality, CHECKING the clearances isn't technically or mechanically difficult, and changing shims isn't rocket science either, and the biggest hassle with the entire experience is getting the rubber valve gasket back in place during re-assembly---an exercise in frustration without having the proper adhesive. Of course, those owners that use a paper valve cover gasket don't even have to suffer that trial.

Also, when removing the valve cover, you should always check and probably replace the valve cover hold-down bolt washers, as that will go a long way to preventing oil leaks in the valvecover area.


PLUGS CHOPS, a/k/a the Zen(ith) of Engine Tuning:

To get even more aggressive, you do what people call a "plug chop"---and you do it carefully! When you remove the plugs after that 50 mile ride, what you're seeing is the color of the plugs due to the last few moments of combustion inside the cylinder......and those last few moments are usually at idle or just off-idle. So your plugs are telling you what things are like with a warm engine, at idle conditions....a very limited (and not-so-useful) insight.

Plug chops are where you run the engine (under load, meaning real-life riding conditions) and then if you want to read the engine conditions at, say, normal cruise speed, you get up to a normal cruise speed for a minute or two, keep it there, and then push the kill button (killing the engine), coast safely to a stop, and remove and read the plugs.....in this way, you get to see what the fuel mixture conditions are (determined via reading the color of the spark plug insulators) is at normal cruise conditions. You can do the same thing at full acceleration, or wide-open throttle (CAREFULLY killing it, lets say, at 5000 rpms in 3rd gear).

This is a much more accurate way of determining what the fuel mixture conditions are inside a real engine, under real conditions. Much more of a pain in the butt, too, which is why most people don't do it. But if you REALLY want to get things right, that's how it's done. NOTE: depending at what load conditions and throttle position you do the "chop" at (meaning "push the kill button") tells you where you might need to adjust things. The pilot fuel circuit is active from idle up to about 2500-3500 rpms, and at about 3000 rpms the main fuel circuit starts becoming involved, and by 4000+ rpms the main fuel circuit is responsible for about 80%+ of the engine's fuel supply conditions. So where you do the "chops" tell you not only what the fuel mixture and combustion conditions are like, but also, which circuits are responsible for those conditions.

This is what is meant by "tuning" a bike via changing fuel and air jets, needle shimming, etc......like when you change the exhaust system or air cleaners to those little "pod" filters.

Finally, here's a little video showing a colortune plug "in action"---kinda grainy, audio not academy-award quality, but better than nothing:

http://www.gadgetjq.com/ctune.htm

Hope you aren't bored to tears yet.....but, at least now you know more than 99% of the other people do!

 

Thanks everyone for there response, I cleaned the hell out of every nook and cranny.
"The Muffin Man" has been loaded on the MP3 player, Black Napkins too, tuning to start Thursday.
:lol:

Chacal,
Thank you so much, that write up explains it well.
I was told the pilot screw only effected the low end but now I know why.
Still a plug read at idle is lean and my issues are below 3K, from the write up, the range of the pilot fuel circuit is "active from idle up to about 2500-3500 rpms"

So hopefully, I do a read, 3rd gear @ 5500 and the plugs will be nice and tan.
This then leaving only the lean idle read which can be adjusted with the Pilot screw.
Don't want to have to borrow the sync sticks and colortune again.
Keeping my fingers crossed, I have a trip in 2 weeks want bike to be right before I go.
This place kicks butt!

 

Great write-up Chacal ! And my package came - thanks.
Now it's time to play with the new COLORTUNE !