Top end time?

[mk2dubbin]

i garrentee the problem is your carb bowls are on the wrong side. the choke leaver side carb should have a brass pin in it on the back and a little jet on the inside. switch them and she shold run just fine and start in 1-3 kicks like mine does

 

actually they are on correctly, and i verified that there is fuel freely flowing thru the pickup tube and starter jet in the bowl. I fixed that issue on a friends banshee this fall and hers started easier than mine even before i swapped them! this bike has just decided this year to be a pain in the ass. whatever the underlying issue is - is something beyond the obvious.

 

keep the ideas coming guys! i will either tell you what i know or i will get an answer as soon as i can get over there to look into it!

[edgehanger]

You said you lost 3 psi in 5 minutes? I think thats too much. I thought you weren't suppose to lose more than 1 psi in 6 minutes. Also sounds like a fuel/carb problem. You said you were 100,000% percent sure the bowls are on the right carb and the choke tube is connected right? With those giant pilots thing should start with half a kick. Couple things you could try.

 

When its cold try to start it with out using choke. If no start try using no choke and holding throttle wide open. If it starts then your jetting is too big. Also try to start it with air filter removed and hold your hand over back of carb. This should force gas up through the carb and it should start. SHouldn't take more than 2 kicks before your hand is wet. If it starts like this with no problems then you are not getting the proper fuel delivery or its that air leak. Do this on both carbs unless it starts when you do it on one. If fuel doesn't get on your hand check the reeds.

[mk2dubbin]

When its cold try to start it with out using choke. If no start try using no choke and holding throttle wide open. If it starts then your jetting is too big. Also try to start it with air filter removed and hold your hand over back of carb. This should force gas up through the carb and it should start. SHouldn't take more than 2 kicks before your hand is wet. If it starts like this with no problems then you are not getting the proper fuel delivery or its that air leak. Do this on both carbs unless it starts when you do it on one. If fuel doesn't get on your hand check the reeds.

 

while I have it apart the first thing I want to do is check the reeds and also do another leakdown test to see if i can further track down the pressure that it is losing. i have been pretty busy with work and since i don't keep the bike at my house, i haven't had much free time to go over and mess with it much. hopefully this weekend i can get to some of it.

 

i need some clarification on your carb tests please. if i put my hand over the outlet of the carb, how will trying to kick it over pull any air past my hand? if it can't flow air past my hand then my hand won't get wet with fuel. i believe i am misunderstanding something, sorry! or are you saying to put my hand over the inlet of the carb, thereby using the vacuum to pull only fuel thru the carb since no air would leak by? that part i would understand, but then why would my hand be wet on the inlet side of the carb and how would the reeds affect that situation?

[edgehanger]

while I have it apart the first thing I want to do is check the reeds and also do another leakdown test to see if i can further track down the pressure that it is losing. i have been pretty busy with work and since i don't keep the bike at my house, i haven't had much free time to go over and mess with it much. hopefully this weekend i can get to some of it.

 

i need some clarification on your carb tests please. if i put my hand over the outlet of the carb, how will trying to kick it over pull any air past my hand? if it can't flow air past my hand then my hand won't get wet with fuel. i believe i am misunderstanding something, sorry! or are you saying to put my hand over the inlet of the carb, thereby using the vacuum to pull only fuel thru the carb since no air would leak by? that part i would understand, but then why would my hand be wet on the inlet side of the carb and how would the reeds affect that situation?

 

Put your hand over back of carb and kick. If everything is fuctioning properly gas should come up through the carb and will get on your hand. The back of the carb where the air filter goes.

The piston stroke pulls air and fuel through the carb and if your hand is covering it, it will pull only fuel. Only keep your hand there for a couple kicks then check to see if fuel was pulled into carb.

 

The reeds open and close as the piston makes it's strokes. If a petal is not working right it will not suck gas into the cylinder right. The piston comes down and force fuel/air through transfers. If the reeds don't close then you're blowing some of that mix back through the intake.

[EvilBanshee]

What kind of fuel are you running? MAkes a big difference for me...

[mk2dubbin]

thanks for the explanation - it makes sense now!

 

as far as the fuel i am running; I run 93 octane from Shell (always) with Klotz Supertechniplate at 40:1 or slightly better.

[mk2dubbin]

just to update everyone that took the time to help so far - i finally did another leak down test and it held 6 psi for 6 minutes. i didn't test beyond that. i had left the foot pump connected to the tester last time so it apparently either leaked at the valve stem or back through the pump. so my only leak was at the boost bottle. i pulled the intakes and reeds and at a glance they look good but i will clean them up a little and look at them closely.

 

i've really been thinking about a single carb setup and so maybe i will head in that direction next since now is the time to do it with the bike ripped apart.