Carb Cleaning 101

I realized that I didn't clean my carbs as well as I needed to, so I googled and found this great writeup with pics. I thought I would share!

http://cycles.evanfell.com/2008/09/how-to-clean-a-motorcycle-carburetor-the-right-way/


How to Clean a Motorcycle Carburetor, the RIGHT way.

Posted on | September 1, 2008 |

I get asked about Carburetor Cleaning regularly both from readers and from friends offline. So I’ve decided to write a definitive guide for cleaning carbs the RIGHT way. So put your tools down for a minute, grab a beer, and give this a read. You might just save yourself a lot of headache and sweat.

Carbs come in many shapes and sizes. Single carbs, dual carbs, racks of 3, 4 or 6, V racks, carbs with ticklers, carbs with accelerators, carbs with asynchronous designs, and carbs that operate vertically. While working on some carburetors is more difficult (due to design) than others, they all share the same basic components, and the process of cleaning those components is generally indentical.

BEFORE YOU START

Make sure that dirty carbs are actually your problem. Lots of things can make a bike run poorly or not start. Weak battery, corroded electrics, old spark plugs, bad timing, low compression, mis-adjusted valves, dirty air filter, and plugged exhausts can all cause poor running. I’ll write an article eventually on how to diagnose poor running conditions shortly, but for now - lets just deal with the carbs.

OK, SO YOUR CARBS ARE DIRTY

Once it has been determined that the carbs are the problem it’s time to get to it. Some racks of carbs are easier to remove than others. If you’re working on a newer model bike the rubber boots from the airbox to the carbs and the manifold boots from the carbs to the motor should be relatively soft and pliable. On older bikes however this is rarely the case.

First remove the fuel tank, seat, and side covers. Depending on your model of bike other parts may need to be removed too. For many single cylinder bikes the carb can often be removed without removing any body work at all.

The bike below is a 1983 Yamaha XJ750 Seca with 4 inline Hitachi carburetors



You’ll want to loosen the circle clamps on all of the rubber boots. Sometimes I’ll even take them all right off (carefully, without bending them too badly) so that they aren’t in the way.

Inspect the airbox. On many bikes it is bolted in place to tabs on the frame. Remove those bolts and try to create as much space as possible for the airbox to pull backwards.

Next, put the bike on it’s centerstand and straddle it facing forward. Put your right hand on the right-most carburetor and your left hand on the left-most carburetor and get ready to sweat. Sometimes you’ll be able to pull the carbs straight backwards nice and easy, but that is pretty rare. I usually end up rotating them up then rotating them down as best I can while pulling backwards furiously. This can really take some work and time, especially if you’ve never done it before. In real extreme cases where you simple can’t get the carbs to pull backwards out of the manifold boots I have a couple tips. These tips should only be used in extremely difficult cases when you have been struggling for an hour and simple can’t get the carbs to pull backwards out of the manifold boots.

Tip 1: Ratchet Straps - This is sort of a last resort, but it has worked without fail for me when I’m pooling sweat on the garage floor and the carbs aren’t budging. Wrap a ratchet strap around one of the outer carbs and put the hooks somewhere on the rear of the frame. Then slowly ratchet the carbs right out of the boots. Be careful not to pull them too cockeye’d or you could damage the boots. Attach a second ratchet strap to the other side if necessary. (Note: you can do this in the opposite direction to force carbs back into the boots once they are clean.)

Tip 2: Full Pull! - You should do this before you do the ratchet strap method above. Sit down on your butt along one side of the bike. Wedge one of your feet up between the forks and the front fender, then put both hands on the same outermost carb and PULL PULL PULL! This might not work so well if you’re short! Ha.

Ok, So The Carbs are pulled back

Chances are the airbox boots are all crammed up now. Do your best to rotate the carbs up and out from the boots and pull them out one side of the bike. Sometimes it’s easier to pull the carbs out one side than the other, so have a look to see if there are frame elements, motor elements, or hoses that may block the carbs from coming out on one side.

Also keep note of the throttle cable(s) and choke cable (if there is one). Now may be a good time to loosen the nuts that hold them in place and disconnect them.

Struggle just a couple more minutes wriggling the carbs out the side.

Ok, You have the carbs off the bike



Make sure you brush off any loose dirt or grime, then flip the carbs over and remove the screws from the corners of the carburetor. Some carbs won’t have bolts in the corner and instead have a wire latch over top which can just be forced over.



Remove the bowls.



If the carbs are real gummed up the insides might look like this:



It’s obvious that these carbs are all clogged up. Some carbs might not look so bad, some might be a lot worse. It’s always a mystery what will be inside the bowls.

Now it’s time to remove the floats. It’s generally a good idea to drench everything in carb cleaner (available at any autoparts store). Sometimes the pins will practically fall right out, sometimes they’ll be so stubborn you won’t think they’ll ever come free. But they will! Carefully push on the pin from either side. Sometimes a nail and a gentle tap from a hammer is helpful. **BE CAREFUL**, using force to remove a stuck float pin can break off the pin tower. If they are really stuck and you can’t seem to work them free here are a couple tips.

Tip 1: Heat - Adding a little flame to the float pin towers can help. **Don’t Burn Down Your Garage!!**

Tip 2: Pliers - Using pliers to gently clamp the end of the pin and push it through has worked well for me in the past. **Don’t break the towers!!**

Once the float pin is out you can remove the floats, the float needle, and unscrew the float jet screen.



Set everything aside. Next remove the main jet, pilot jet, and idle jet (if there is one). They should come out easily with a flathead screw driver.



Set them aside.

Next flip the carburetors back over and remove the caps. Underneath the caps is a rubber diaphram with a spring. Sometimes the caps have a tendency to shoot off the top, so be very methodical when removing the screws. Other times the cap tends to stick down until you start to pry at it, then it shoots off, again, just be cautious and don’t loose any parts.



Next you’ll want to gently pull the slides up out of the carburetor body. You can gently pull on the rubber diaphrams, but be very careful not to tear them. If they don’t come up easily stick your finger into the carb intake and push the slide up with your finger. You can also gently pry it with a screw driver (gently). If it doesn’t want to budge don’t force it. Instead finish reading this article and pay attention to the boiling tips further down.



Now your carbs should be pretty well emptied out. If the throttle on the bike moved fluidly and smooth there is little reason to do much to the carb bodies themselves. However, if the trottle was real sticky or frozen there are a few things you can do to free it up. Sometimes just drenching all the throttle components on the carbs and letting it soak is enough, other times it is not. I generally try to break racks of carbs apart. It isn’t often necessary and can be confusing to put everything back together in the right places. Also, the little rubber connector hoses and o-rings have a tendency to crack or leak if you mess with them. If you can’t work the throttle back and forth until its smooth have a look at the boiling tips further down.

 

Keep it Neat

Organization pays off.



Clean the Main, Idle and Pilot Jets

Hold each jet up to the light and see if you can look through it. The idle and/or pilot jets have extremely small holes so make sure you are looking through them straight. If you can see through the jet it isn’t clogged. There could be a little gunk built up around the edges so spray them down with carb cleaner and let them sit a bit.

If you can’t see through the jet it is clogged and needs to be cleaned. Always try the easiest things first. Here’s an ordered list of a few things you can do to clean the jet.

* Blow through it. - Rarely works, but hey, who knows.
* Compressed air. - Force 100 pounds into it. Works occassionally. Make sure to hold the jet tightly so it doesn’t go flying across the garage. You might put the jet back into the carb body to hold it in place for this.
* Soak it in cleaner. - When I first started cleaning carbs I thought carb cleaner would be the magic answer. It isn’t. In fact, I hardly ever use carb cleaner any more, because it simply doesn’t do a very good job of anything but removing varnish from the bowl and slide. But try this.
* Poking it through. - Collect a few different diameters of needle like objects. A wire from a steel bristle brush works well, a bristle from a broom works well, a baby pin, small sewing needle, etc. Very gently try to poke it through the jet. If you are using a metal needle use caution, brass jets can scratch and deform easily.
* Boiling! - This works better than anything. Toss the jets into a pot of boiling water and let them bounce around for a couple minutes. When you pull them out blow some compressed air through them and you’ll most likely be good to go.

Some idle jets can be real tricky and never seem like they’ll be cleaned out . . . Just keep working at it, I’ve never met a jet that couldn’t be cleaned.

Cleaning the Choke and Air Mixture Screw

Air mixture screws have a tendency to strip or break. If the carbs were real gummed up you might find that the air screws are stuck. Don’t force them, if they don’t want to come out, just leave them for now. It is fairly rare that these screws will need to be cleaned because they are above the float level. If you can get them out just wipe them down with carb cleaner and spray some through the jet.

Cleaning the Slide and Needle

These are easy to clean. Squirt them with a bit of carb cleaner, wd-40, or anything similar, then wipe them down with a rag. Once the varnish is gone they’re good to go. Sometimes they get heavy varnish on them which I will scratch off carefully with a piece of plastic. Scratching the slide and needle is a BAD thing, use caution.

Cleaning the Carb Bodies

Use the same squirt and wipe method noted above. Most of the time the other pressed jets and passages in the carburetors won’t be clogged. But if the bike has been sitting a real long time with squirrels in the airbox it is certainly possible. Us a compressor to blow some air into every passage you can see. Listen for the air coming out the other side. If no air compressor is available use a can of WD-40 with a straw attachment.

If some of the pressed jets are clogged it can be difficult to open them up. There are a few things you can do.

* Carb Dip - Most autoparts stores sell carb dip. It comes in a can similar to a paint can and is a VERY harsh cleaning agent. Soak the entire carbs in this dip. This dip can eat at rubber and plastics if they are submerged for too long, so try and remove everything you can from the carb bodies before soaking them. Once you pull them out swish the carbs around in a bucket of water to clean off the excess dip, then hose them down with WD-40 to get rid of the water.
* Boiling in Water - Not many people do this but it is by far the best way of cleaning carburetors. Dropping the carbs into a pot of boiling water will instantly free up stuck slides, throttle plates, and other frozen parts. It will also loosen the dirt and grime clogging up pressed jets and other passages. Just make sure to dry the carbs thoroughly with compressed air or the sun afterwards.
* Boiling in Lemon Juice - There is NOTHING BETTER at cleaning carbs than a giant pot of boiling lemon juice. The acidity from the lemons eats through everything; gas varnish, oil build up, dirt, grime, etc. Sometimes I won’t even bother doing anything but this - I’ll just remove the bowls, remove the caps, then drop everything into the pot and let it sit for 20 minutes (rotate them a few times). The one caveat to doing this is that you’ll want to wash the lemon juice off the carbs as soon as you pull them out. So have a bucket of water ready, or a can of WD-40 to hose them down. Also note that the acidity has a tendency to put a dull finish on the aluminum bodies of the carbs. This isn’t a problem in most cases, but if you must have everything shiny be prepared to do a little scrubbing and polishing afterwards. It may sound weird, but trust me, I just saved you LOTS of time. (Most dollar stores sell 1/2 gallon jugs of lemon juice, so buying a few gallons will only cost you $6. Plus you can put it back into the bottles afterwards and save it for next time.)

Cleaning the Bowls

This is pretty straight forward. Use any of the methods above to tranform your varnished bowls.





Most carb bowls are simple, just clean them up and they are good to go. But I picked this Hitachi’s for photos because they have a jet built into the bowl. You can see the ‘fifth’ hole along the edge of the bowl, that is actually a thin passage that extends to the bottom of the bowl. This is for the idle jet and is extremely important. If these passages are clogged, the bike won’t stay running, period. Use the same poke, soak, and boiling methods outlined elsewhere in this article. Not all bowls have these passages, only some, if your’s don’t - good for you!

Once Everything is Clean

Now that everything is clean it’s time to put it all back together. Take your time and make sure you put everything back where it came from. WD-40 is your friend. When screwing in the jets don’t over do it, they only need to be seated and snug, do NOT use any force putting the carbs back together.



If the bowl gaskets got goobered up you can put a little RVT on them. So long as the float needles are still in good condition leaky gaskets shouldn’t be an issue. However, prudent carb tinkerers may want to order replacements if necessary.

Once the carbs are back together stuff them back into the bike!



Extra Notes

* Rebuild Kits - This guide did not mention rebuild kits until now. Rebuild kits (consisting of new gaskets, jets, needles, etc) can be purchased for nearly any bike, both old and new. 95% of the time these are NOT needed. I have rebuilt enough carbs to block off main street, and only once have I used new parts. ONCE!
* Carburetor Adjustment - Carburetor adjustment, setup, jetting, and synchronizing is a whole encyclopedia waiting to happen. Those topics are not covered in this article, but I will address them in future articles.
* Carburetor Polishing - External carb asthetics will be important to some, and not to others. Cleaning is all I am covering here, this will be addressed in the future.
* Work Space - Make sure you have lots of space to keep organized. I also like to work on a wooden surface because it absorbs the spilled gas and cleaners rather than pooling.

That’s it! You’re Done!

I’ll continue to write a couple more related articles about diagnosing carburetion issues as well as the proper way to adjust, jet, and tune your carbs.

 

Great timing, I was just headed out to the garage to remove and clean my carbs for the second time because I didn't do it thoroughly enough the first time. I'll be following the info you provided along with some others that I got on these forums. Thanks

 

Thats a nice write up. You might want to add as long as you have the carbs down and the rack broke apart to repalce the fuel tube o-rings and throttle shaft seals. Those will give most guys here trouble and its cheap insurance to make sure you have good tuneability and no gas leaks from shrunken o-rings. Remeber these carbs are 26 years old at lt least and the rubber goods should be looked at.

MN

 

No new float valve seats and needles? Re-use a 26-year old float bowl gasket by slapping some RTV on it??? No o-rings for the pilot mixture circuit?

Ummmm......gosh, I hate to say this, but the above article is the way that many people typically go about cleaning their carbs.....quickie "rebuild", concentrate on getting the externals and visible surfaces all nice and shiny......the first time around.

Eventually, by their second or third try at "cleaning them", they finally get it right......

 

hi chacal,

Can you help me out I'm looking for new carb throtle shaft seals for my 82 xj650j maxim
I made my own out of a supposedly gas resistant rubber but they swelled up and slowed my throttle backing off

any help would be greatly appreciated
thanks

 

THROTTLE SHAFT SEALS:


aaa) Aftermarket Hitachi HSC32/33 series carb THROTTLE SHAFT SEALS (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. 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

ha I found it on one of your earlier posts I'm starting to figure out how to utilize the search engine
thankyou wizards

 

Nice job.
I recommend one commandeer a muffin tin from the kitchen. The kind that holds 12 muffins.
3 rows of 4 each.
Label the carbs 1 thru 4 and do the same on the muffin tin.
That way, as you take them apart, you can place carb parts in respective tins, full of your favorite soaking mixture.

 

Fully agree with Chacal. I would tap dance around not breaking the rack. Once you do it and replace those seals its not that hard. AS far as syncing goes I think it really helps to not be pulling air in around the throttle shafts.

All the carbs we have done and gone the extra to change the seals and o-rings. Have all worked real well and tuned in nicely. I'm convinced thats the way to go from now on.

MN

 

Chacal, this thread is titled "Carb Cleaning 101" becuase it doesn't include anything related to carb rebuilding, such as replacing O-rings. I'm sure you meant well with the suggestion, but this thread isn't really the place for tips on how to rebuild the carbs.

 

if you have the carbs all apart to clean them you should replace the worn parts you find but go ahead and put them together with your old worn parts so you can take them all back apart agian when you still cann't get them tuned in right if you like doing things twice have at her

 

You shouldn't "Break the Rack" and separate the Carbs UNLESS there is something requiring the need to do so.

Leaks:

If the Fuel Supply Gallery "Tees" or "Connecting Barrels are leaking beware of replacing Pressed-in Parts.

On some Carbs the Supply T was a solid T with raised "Bumps" instead of O-rings.
IF that Part is leaking you have two Options:
Replace with the O-Ring Type of fitting, ... -or- ...
Apply a tight-fitting section of Electrical Shrink-wrap to the NON-O-ring type end.
Heat the Shrink-wrap and smooth-out any wrinkle.
Use a New Pencil with a rounded-out eraser as a smoothing tool or just grit your teeth and use your finger!~ : ) (Be a man!)

The Heat Shrink needs to be lubricated with Synthetic Grease smeared on it to re-seat the fitting.

 

LS1, I agree with you, but a lot of people are going to read this very nicely illustrated and well-written article and think to themselves, "wow, that's all that I've got to do to "fix" my carbs!".

And many of the rest of the threads on this website testify to the fact that it just isn't that e-z..........

The author is an extremely skillful or lucky fellow to have been able to rebuild enough carbs to block off main street, and only once had to use any new parts.

Of course, "rebuilding" and "having them perform properly" could be considered 2 different things, so I suppose it's possible to have rebuilt quite a few hundred sets of carbs, but still not have them perform properly, although I don't think that's what the author intended to mean!

I have bought, rebuilt, worked on, and rebuilt for others (after they have tried and given up) enough carbs on these Yamaha's to know that what one person means by "rebuilt" (often confused with the term "cleaned") really ain't.........

 

well I certainly agree with replacing any worn or damaged parts you may find, but if your attempt is to clean the carbs, then this is the exact, perfect thread for that.

I would think that this type of cleaning should be done as normal, routine, yearly maintenance. So, if you perform the steps in this thread to try and fix some reason why your carbs may not be running well, then I would expect to either find a part that needs replacing, or a buildup of varish or debris.

 

Let me ask you this - Why do you clean your carbs?

Is it to make them look pretty, or is it because they're not working right?

I would have to agree with Chacal and Mn-Maxims on this. If you're taking them apart anyways, why not inspect and replace any worn/damaged rubber parts?

 

Not a bad idea, at all!

 

As with Fuse Panels and Alternator Brushes; we have arrived at a "Point in time" where EVERY XJ-Owner should do a needed cleaning and Tuning Function to assure the Carbs operate as they should.

Diaphragm Bore Cleaning and Re-Finishing

The 25-Years of time have affected everybody.
The Diaphragm Bores on every set of Carbs I've seen lately need treatment.
All of them were hazy with Aluminum Oxidation.
The Oxidation acts as a thin "Powder Coating" on the Bore. The Oxidation SHRINKS the INSIDE DIAMETER of the Bore. This is NOT a situation where you can even "Feel" the difference. You CAN see it, though.

When the Bore Oxidizes over ... the Powder Coating like tarnish ... effects the performance by causing the Diaphragm Piston to:
Stick
Shutter
Bind
Hesitate
Freeze

Any one of those situations causes a MAJOR Performance Issue.
If your Bike isn't Accelerating or Decelerating smoothly.
Backfires unexpectedly.
Boggs-out unexpectedally or
Stalls ... even thought it runs very well most of the time, ... you might be suffering from the Bores not letting the Pistons rise and fall.

From these sets of Conditions was born ... "The Clunk Test"

Please refer to the Clunk Test
You havent really cleaned the Carbs unless they PASS the Clunk Test!

 

Nice article with great pictures. But hey, I know I'm not the only guy out there that after taking out the main jet, removes the washer underneath, and taps out that brass insert with all the little holes in it. I have found that part with almost all the holes clogged. I don't think I've ever done a cleaning without removing those things. Also, I agree with the guys who want to replace all the rubber stuff. Its a great idea, but like somebody says, I'm usually trying to do a "quickie" job and trying to get rolling again. However, I did learn something, and the next project is my old 1982 Seca Turbo xj650 that's been sitting for over 10 years. Its only got 8k original miles, and its clean top to bottom. Yet, its going to take me forever to go thru everything to get it back on the road. I'll be changing out as much rubber as possible, including the tires.
Take care foks,
IB

 

I recently cleaed out the Mikunis on my XJ and I found that interdental tothbrushes work a treat for the little holes! tepees seem to be the best.

 

Great info on how to get that crap out.
In my experience, I often find the throttle shaft seals ok and I don't break down the racks in less I have to.
In our XJ bikes, the brass jet in the float bowls are for the choke systems. If one is clogged, the bike will run on 3 cylinders when cold with the choke on.
I use a small torch to heat the area where the choke jet is and quickly blast it with compressed air. Works every time.

 

despite all the crap y'all are giving 98formulaLS1 for his simple tutorial, I think we can all agree that his thread has something that RickCoMatic nine yards tutorial DOESN'T have--pictures! Now if this tutorial kept on going with the same detail as Rick's, AND had the pictures, then you couldn't top it for tips OR clarity. The whole "THIS is considered dirty or bad, and THIS is good and clean" thing would really be useful to those of us with an untrained eye.

Rick, your carb-cleaning tutorial is amazing and i used it on every step of my cleaning. My carbs all seem to run great thanks to you. But honestly, you could have saved a lot of writing and descriptive words if you had just included some pictures with it. That way people will know for sure what you're talking about and where it is. Before you take a jab at me, i just want to say that I DO understand that not all carbs are the same make, but still... honestly, though, i owe you money (not really!) for the help your tutorial provided.

I love being a member of this forum and I love all the tips and the help everyone gives on issues that confuse me. I would have given up long ago on my bike, or else royally screwed it up LONG AGO without this forum, but one thing that just bugs me, is how there's no concise location for easy things.

It took me like 45 minutes to find out what a "clunk test" was. I had to search through something like 12 threads to really understand what people meant when they kept saying "bench sync" and to this day, I don't know EVERYTHING that is needed or expected for a bench sync. I think I did it all, but newbies won't know what that terminology is, and it'll take them forever just to find out, just like it took me. I don't expect you veterans to understand where i'm coming from because you've been here so long and know a bunch of threads where this info is located.

i just got my bike running yesterday after putting the carbs back together and on the bike. It's running rich. i've READ people's comments to "check the mixture screws". where the HECK are the mixture screws? are those the same things as the PILOT screws that Rick talks about his in 9 yards tutorial? (i'm just waiting for someone to tell me to suck it up and finally buy the repair manual...)

 

Might try this, scroll to the very bottom for some useful links!

http://www.xjbikes.com/Forums/viewtopic/t=14692.html

 

Pilot screws = mixture screws
They are at th front of carb..engine side...enrichment mechanism on one side
pilot screw th other side. May have a cap on them that you need to remove
that trick is well covered among all th other carb info on here. And uuhhh
manuals are good to have handy.

 

The Pilot AIR Screws control Pilot FUEL to the Engine.

Although they control AIR, they have earned the neme Pilot Mixture Screws, ... because the more AIR they are adjusted to letting pass into the Engine, ... The more FUEL they cause to enter because the AIR Passage is Married to the Pilot FUEL Jet.

The Pilot Mixture Screw, when brought-out from Botttom meters AIR Pulled into the Engine.
The Rushing Air causes a pressure differential and begins to include FUEL from the Pilot FUEL Jet Passage.

As the Screw is brought-out further as it is lifted through the O-ring at the bottom of the Screw Adjustment Port ... the Volume of FUEL allowed to pass into the Combustion Chamber is controlled very precisely as the Screw lifts and opens the Air Passage.

Depending upon weather your Pilot Screw is Fine or Ultra Fine Threaded will determine how far the Mixture Screw needs to be withdrawn to provide ...

A suitable Air~Fuel Mixture to Ignite and allow the Bike to Idle.

Once the Pilot Mixture Screws have been raised enough to provide the Engine with a Mixture containing enough FUEL to Ignite and allow the Bike to IDLE ... further adjustments are made which fall into the category of Fine Tuning.

Additional FINE Tuning, bringing the Pilot Screw OUT >> Enriching the Mixture is necessary for:
Adding a smoothness and eliminating Lean Backfire to the Idle Mixture.
Smoothing-out the Idle
Enriching the Mixture to sustain a suitably enriched Mixture at the moment that the >> Throttles are Opened and Clean Air rushes into the Engine which does NOT contain nearly any Fuel.
This moment is called: Off Idle.
The Pilot Mixture Screws need to be RICH Enough with Supplemental Richness, ... to SUSTAIN Combustions for the
>>> 5 or 6 Rapid eye-blinks that Intake Air will require Fuel <<< before MAIN Jet Fuel will Supply the Engine.

The Amount of Turning the Pilot Mixture Screw OUT will be very small. Measured in Degrees. This amount will VARY form Bike to Bike depending on the condition of the Engine and the Integrity of all the component parts and manifolds.

The Air~Fuel Mixture can be VISUALLY Monitored using a device called a Gunsun "ColorTune Plug"

Search Keyword: ColorTune

Thank you for the kind words.
I'm adding pictures.
PLUS >> Because I was ill and unable to attend to my Winter Maintenance, ... A VIDEO ... on DVD of Cleaning Hitachi's almost in Real Time.