What kind of fuel should I use?

Question

1982 kawasaki 440

The motor has 20 thousand miles on 'er and runs after I finally get it to start after it has sat for a while. I dumped in some fresh 87 octane mixed with about half a bottle of seafoam and the motor is running really rough and idling poorly... I'm sure part of this is the Seafoam, but I also don't know what octane of fuel to run.

From what I've seen online, I've seen numbers range from regular 87 octane to 93 octane.

So what octane should I use? I've only got about a gallon in the tank, so mixing in another couple of gallons ought to help mix in the Seafoam and 87 octane fuel.

Yes, it sat for a while before I got the bike, but I've already replaced the plugs and cleaned the carbs. It just runs funny on the 87.

As stated, I've already dis-assembled and cleaned the carbs. The fuel is fresh as of a couple days ago so thats not a problem either.... I just got 87 octane because I didn't know what kind of gas I needed at the time and now I just need to know what I need for in the future... higher octane, it looks like...

Answer 1

u might have problems if the carbs is out of synch. i wouldnt be surprized if this bike has a high compression engine. if so, it would be best to run 93 octane. u might have wound up gettin a batch of bad gas...like water in the gas. try draining the tank, refilling with 93 octane. if that smooths out the idle, then problem solved. in my bike, the engine is a high compression...and runs the best on 93, and chitty on 87.

Answer 2

Try putting some of the highest octane in and see if there is an improvement after riding several miles.

Seafoam works good to clean out carbs, inlet valves and such, but if your bike has been sitting all winter with old gas in it, you may still need to take the carbs apart and clean out the jets, orifices, etc.

And a bike that old might benefit from a carb kit. I think Keyster makes a carb kit for that bike. Check with denniskirk.com or bikebandit.com and see if they have em.

RESPONSE ADDED:

Have you thoroughly checked your ignition system? I can't remember if that bike has point & condenser or it's electronic. But if it has points, you may want to check them and the timing.

Have you checked your air filter?

And just to make sure, did you check the idle mixture screw. On that bike it's hidden under a cap that you must pry out to get at it. It destroys the cap to pry it out, but it's not necessary anyhow...I have no idea why it's even there.

Have you synched the carbs? If you haven't and don't want to buy a sync tool, you can make your own from aquarium hose, a metre stick, and some type of fluid.

Basically you attach the aquarium hose to the metre stick with a "U" shape at the bottom and support the metre stick in an upright position. Then put a little bit of fluid into the hose and let it settle in the "U" area (I use 2-stroke oil because it's blue and shows up good). Then hook one end of the aquarium hose to the vacuum port on carb #1 and the other end to carb #2. (You might have to mess with some fittings to get a good seal at the vacuum ports...Mine were the right size for the hose to just push in). Then start it up and let it idle a bit. Then adjust the screw and locknut between the carbs until the fluid at the "U" is at the same level on both sides of the "U". Don't run the motor if you've only got one end of the hose connect though, or it will suck the fluid into the carb.

If synching doesn't solve the problem, then I'd suggest a rebuild of your carbs.

Answer 3

Run the tank of regular octane fuel, and see if it pings. If not, then you can run it. If yes, then switch to high octane.

From what you are saying the problem seems to be that it is running roughly, not pinging necessarily. I would check to make sure there is no vacuum leaks around the carb(s).

Run the tank with the seafoam, if able, until it is almost gone, then put in fresh gasoline. Run it for awhile and see if it clears up the problem. If not, also remove a spark plug and see if it is white, or black. If it is white, it is too lean, and adjust the carbs. If it is black, it is too rich. The plug should be a light tannish white.

Answer 4

Did it sit for a long time and did you use engine stabilizer before you let it sit? If the answer is yes then you need to remove the carburetor and clean out the jets because they probably have gasoline byproduct buildup. Buy some carb cleaner and blow it through the jets (once they've been removed) If you have a air pressure gun then alternate between carb cleaner and the hose.

The gas must not only reach the engine but it must reach the engine at an optimum level of atomization to cause peak performance.

Answer 5

Take the old gas out. Gas already starts to break down after a couple of months. Your going to save what 4 dollars?
If there was no gas to start with then you'll have to clean or rebuild the carbs. Gaskets and rubber probably dried out, and if there was gas in the carb when it was put away It dried up and formed a varnish in the bottom of the float bowl.

Answer 6

try premium if that doesnt work your going to need a rebuild and a sync job