Questions On Leak Down Test

[yellow&chrome]

Is a leak down test on a banshee to be down one side at a time or the whole motor at once? If it is supposed to be the whole motor then my motor is holding 6lbs. for 6 minutes. Then why is the left side lean and the right side rich if I have no leaks. Thanks in advance for all your help!!!

[badass_r6]

the leakdown test should be done one side at a time. if your bike has no leaks and is lean on one side, maybe look at your carbs. how do you know its lean? did you read the plugs? and another thing, did you do a compression test? make sure your carbs are sinc'ed. was the bike running good and then it just started doin this or did you modify something and then this started? just some questions some people might ask to help you.

[yellow&chrome]

Well I can't seem to get each side to do a leak down, but the whole motor will. So what seal is leaking for the air to go from side to the other side. Yes the carbs are sinc and each side sits at 158lbs. I am readng the plugs to see that the right side is rich and the left side is lean.

[vmaxup]

The leak down test can only be done for the whole motor. There is no seal between the lowerend.

 

 

Then it has to be your carbs. take em apart and clean them. look for something in your main get.

 

Do you run a boost bottle and when you do your leak down are you useing you carb boots. They tend to rip if your running a boost bottle. Get rid of it if there ripped. No advantage with a boost bottle.

[yellow&chrome]

Thanks for your response vmaxup. no i do not run a boost bottle and yes I do do my leak down with my boots on. Why would badass r6 say that i should only do one side then the other. Good news is that my whole motor does hold 6lbs. for 6 minutes. My carbs have been cleaned several times and main jets triple checked any other suggestions for right side rich and left side lean according to the spark plugs.

[vmaxup]

I dont know why he said what he said but if your holding then you do not have a leak.

And you checked your carbs so.

Let me think just a process of elimination.

 

You have the little tube between the carbs in right?

 

IS your float height at 21 mm on both carbs and all 4 bowls?

 

Also pull your hoses for fuel of and see if there both poring out gas the same one might be pluged.

 

One other problem could be the filter in the tank is plugged. not letting enough fuel to go to the other carb. The fuel will go to the shortest route carb first .

Pretty shure that would be the left side first and your rich there. (just searching for an answer.

 

One thing I did not ask. Dose it run well or not when it is running?

No backfire?

 

Im thinking float height on your left carb is off. it closes the main and that bowl is running out of fuel.

Let me know what you find. Ill sleep on it and get back with you.

[Bigairee]

Think of it like this. If yoiu can run a single carb to feed both sides of the motor then you would have to plug the other carb to get it to pressurize.

[boonman]

I have no idea where that one is going bigairee, but on a leakdown, you MUST plug the other side. THe carb inlet, and the exhaust. Is your jetting the same yellow? Are the carbs squeaky clean. You need compressed air and carb or brake cleaner. Take the jets right out and clean everything. Also, look for a torn boot. It does happen.

[vmaxup]

boonman

 

He didnt mean plug exhaust or intake he ment (ithink) one cylinder complete at a time.

Its impossible to pressurize one cylinder and not the other during this test.

 

 

 

Yellow and crome.

 

Do you run a boost bootle.

You might be plugging itfor the test to far inside the boots. The cross over tube or Boost bottle might of ripped the boot from vibration. I have also seen throttle cables wear a hole thru a boost bottle

Im replaceing a torn set right now on my 96