Motorcycle Repair: Cleaning Carbs, pilot jet, air mixture


Question
You provided the below response to a guy that owns a similar bike as mine and is having a very similar problem.  I am having a hard time keeping my FZR1000 running without the Choke applied.
Would you please elaborate on your method of cleaning carbs?  Thanks,
Kennon


Hi Steven,

What kind of work has the "shop" done to the bike?

Real quick: Do you have a new/clean air filter in it?
Dirty air filters can cause a bike to run rich and that can cause it to bog.

A couple more questions...
-Is the bike stock?
-Has any jetting been done to the carbs?

If the bike is stock and no jetting has been done and you have a clean air filter, then I suspect you've got a dirty carb jet.
You can usually run some carb cleaner through the tank to fix this type of problem. I recommend using a product called "Sea Foam". But no matter what type of carb cleaner you run through the bike, make sure you only add the amount the package recommends; don't dump the whole bottle in.

If the carbs are really dirty, then you will have to take the carbs off and give them a good cleaning. I have a method I can provide on cleaning carbs if needed.  

Answer
How I clean carbs...
A couple of things first..you don't need to completely disassemble the carbs to clean them and you don't need to purchase a carb rebuild kit, unless you have a bad seal or bad rubber on the carb. In most cases, the rubber is fine.
- Remove the carbs from the bike (following instructions in your manual). You do not need to separate each carb from each other; leave them joined to each other.
- Remove the float bowl. Then remove the floats and the float valve.
- Remove the main jet and the Needle Jet holder (what the main jet screws into).
- Remove the slow speed jet and the pilot jet/air mixture screw (be careful with this one, as there is a small spring and washer and rubber seal on each screw).
- Now on top of the carb remove the top cover off each carb (four screws). Be careful removing the final screw as there is a spring underneath the cover and it could shoot out when you take the cover off. Remove the spring.
- Peal back the rubber on the slide slowly and be careful not to rip it. Pull the slide out.
- Now soak the carbs, jets, floats, slides, gas lines and whatever else that was on the carb, in some carb cleaner. I know Gunk makes a carb cleaner sold in a big jug at WalMart.  There are many kinds though...some are environmentally friendly and smell like citrus. Its up to you. I've even used Diesel fuel, but that can be really bad for you. Let it soak overnight. Turning the parts over every once in a while helps too.
- After soaking, arm yourself with some rubber gloves, a toothbrush, compressed air, needle nose pliers and lay out some clean rags.
- Pull each piece out one at a time with the pliers. Give it a scrub with the toothbrush, rinse it and blast it with compressed air. If it is a jet, be sure to blast all of the holes in it. Then wipe it off with a rag and place it on top of another clean rag.
- I would do the carbs last. Be sure to scrub all the dirt off on the outside of them. Then blast any and every hole on or in them. Be careful that your face isn't on the receiving end of one of the holes, or you will get a blast of air/carb cleaner on you.
-Once everything is clean and dry you can reassemble everything and put the carbs back on the bike.

Some tips:
- Don't go nuts removing or tightening the jets. They are made of brass which is soft, and can strip or get damaged very easily.
- If you turn your pilot jets/air mixture screws in first and seat them lightly, make a mental note of how many turns for each one. That way when you put them back you can set them at the same spot. Otherwise you will have to refer to your manual for the setting for them.
- The rubber boots on the back of the carbs come off pretty easily. But getting the carbs out of the rubber boots on the engine side can be a challenge. I've used a hockey stick to pry against the engine and the carbs to pop them out (and to pop them back in). This can save you allot of struggling. If you are worried about scratches you can wrap the stick with a rag.
- The hair dryer is your friend. I use a hair dryer to heat up the rubber on the slides just before putting the caps back on. The rubber generally shrinks a tad and it doesn't always seal perfectly. Heating it with a hair dryer expands it enough to make it seal again.
I also use the hair dryer for heating the rubber boots on the back side of the carb (air box side) for when the carbs are being installed again. I get the carbs popped back into the rubber intakes on the engine first, then I work the boots at the back on to the carbs. Heat them with a hair dryer and make sure they are pushed on all the way. You don't want any air leaks.

I hope this helps?