OT: Motorcycle Guru's, Dual Carb Question Options

[saigon71]

My Ninja 250 (don't knock it till you try it), won't idle without the choke on at least part way (after warmup). There is a definate flat spot through the low RPM range, but once you break through it, the bike winds out well. It has been this way since it rolled out of the shed after winter. I have some sea foam carb cleaner in the tank, and while I have not been riding it a lot, things have not really improved. Idle jet clog?

Thanks.

[TargaToy]

Sadly, I don't think draining the bowls is going to help you. Very tiny passages are likely plugged. The only way I know of to correct this is a thorough manual cleaning. You can do it. Just take your time and write stuff down/take pics for reference along the way in case you're nervous about putting things back together the way it came apart.

Another thing:

Float bowl screw heads are soft. Make sure you use a good #2 screwdriver tip if you go to remove them. Once you bugger one up, it's a pain to remove the screw. A lot of times, I put a tip in a 1/4" socket and use a 1/4" drive wrench so that I can push into the screw hard with one hand while having the added leverage of the wrench to break them free.

[Prospectfarms]

Targatoy has obviously done this before and is spot-on, but for my own gratification I'll add some color commentary.

1. You have a nice motorcycle that I've always liked. Kaw. gets astonishing HP out of that 1/4 liter engine on your bike. The redline is something like 10K. You better believe the tolerances are tight. This means the carburetors are painstakingly designed to atomize fuel properly -- lots of little holes and passages to clog. If you can't get comfortable pulling and cleaning your carburetors, you won't be able to ride your motorcycle very much.

2. Who ever posted the advice to use Stabil all the time is correct. It retards the chemical process in ethanol/gas mixture that creates gummy crud in the gas. Since ethanol is highly reactive to water/condensation, you must also try to be very careful to keep your tank full when not riding it.

3. NAPA has one gallon cans of carb cleaner with their own basket for soaking. Dissemble the float bowl, floats and anything else that is not metal from the carb and drop it in for a couple of hours. Then blow everything out with air.

4. Don't use wire on jets, you really shouldn't need to if you unscrew them. But you will need to use wire on the idle air bypass ports. These are the little holes you see inside the carburetor on each side of the throttle butterfly. There is some really small piano wire you can buy at some hardware stores that is perfect for this. Every one of those tiny holes is actually the end of a tunnel that needs to be clean for the carburetor to work properly.

5. Buy a rebuild kit or just the gaskets so you can put everything back together.

6. EPA covers as mentioned earlier are designed to prevent you from richening the mixture. They are usually caps or studs that prevent the screw from turning. Unlike 914's, adjusting the idle screw affects overall A/F mixture. Your bike might run a little better and cooler with a very, very slight increase of fuel in the mixture. It's best to adjust these on the bike since that is part of the sync process anyway.

7. Pull the carbs out together. There is usually one side of the bike they come out on. Don't take them apart. Make sure you get a good tight fit on the intake boots when you re-install them.

A great thing about those Ninjas is that there's lots of parts available and lots of internet help too. I'd really suggest doing at least some of what Targatoy and I describe. It's just not as hard as it sounds and is the only way to keep those cool machines running. Good luck. Be careful.