Rookie Carb Question

[TheCafeKid]

You're right, it's a NEWER one, but it works pretty good. All positions on the petcock work correctly. Just to be clear, I keep the carb #2 hose plugged with a screwdriver, and try to start it?

Also, I really feel like I did everything I could to fix up those carbs, but it's clear that the problem is still the carbs. You mentioned that the #2 carb nipple is a vaccum, but it seems like it blows externally, is that correct?

The only thing strange I noticed about the carbs is that on one of the bowls, the the release valve screw is puttied in, and I wouldn't be able to release any fuel if I had to, but when it was running, it didn't bother anything.

Did you soak these carbs in Berrymans Chem Dip or something of the like to clean them? Just shooting spray in em doesnt work man. You have to assure that they are completely clean..every little passage is spotless, and the only way to do that is to dip them for 12 hours or more...
If you DID do that then lets go thru this again... Im not super familiar with the 450s but I will give it a shot. The FUEL line, the fat one, goes to the T in between the carbs. The number TWO carb has a hose barb on it for the vaccum line for the petcock. The line should go straight from the carb to the petcock..no stops in between.. any hose barbs on the BOTTOM of the carbs if there are any, are simply vents to air...they dont connect to anything...

[pnwesside31]

Thanks for working with me on this.....

BTW, here is a link to the diagram of the carbs on my bike...http://www.bikebandit.com/suzuki-mot...g-1986/o/m6037

So, there's a total of 4 valves between carbs, the 2 lower ones with a "fat T" connection is connected to the fuel line. The other 2 upper ones are connected to eachother through smaller hoses and a smaller "T" connection to make one hose. Earlier in the post, people said this connects to air.

As far as the cleaning, they were definitely soaked. I could always try again.

[Sandy]

Sounds like those carbs are driving you mad!!! A good way to confirm the passages are clear is to buy some canned air like those for cleaning computers and with the nozzle attached blow some air though all the small passages in the carb and find out where the air comes out. Compare each carb with the others to make sure they are all blowing air out of the same passages equally. There will be some variations with the vent passages depending on carb placement and whether it has a vacuum line or not. If all is well they should work and you've now learned which passages do what. Good luck with them.

[chef1366]

With the carbs off the bike and the float bowl off
Spray carb cleaner into the two jets on the filter side of the carb. The left screw in jet (pilot air jet) will blow out the pilot jet and the one on the other side (main air jet) will blow out the main. These jets are what sucks the fuel out of the float bowl and into the engine. If the jets or ports are clogged in any way you will not get fuel or limited fuel.
I have only been able to get these clean by a good soak in Berrymans or a good carb dip.
Also if you have the pilot jet rubber cap there is a port connection the main jet passage to the pilot jet. This where the carbs divert the fuel from the main to the pilot while the jet needle is blocking the main. Make sure this is clear also.

[pnwesside31]

Sounds like I need to do an extensive cleaning again. I really thought I took care of all that, but I'll give it another shot.

Do my connections sound correct?

Also, If all is clean including passages, I should be good to go right?

[Sandy]

Also, If all is clean including passages, I should be good to go right?

Yup, just spend a little extra time on your bench sync and you should be good to go, at least with the carbs.

[pnwesside31]

Another question........other than making sure the carbs are extra clean, and all the seals and gaskets are good, is there anything else to a "rebuild" or is there more?

[chef1366]

Set float heighth

[TheCafeKid]

Sounds like I need to do an extensive cleaning again. I really thought I took care of all that, but I'll give it another shot.

Do my connections sound correct?

Also, If all is clean including passages, I should be good to go right?

From what i can tell from that diagram..and again, im not terribly familiar with the 450's set up, I am just judging from the XS400 that ive worked on here at the house, and it used the same carbs, tho not QUITE the same set up:

The BOTTOM "T" is the FUEL INLET, so again, your fat fuel hose goes there. The line from the top of carb two on the MOTOR side of the carbs is the vac line i do believe, that plugs in to your petcock on the only barb that will fit. The TOP "T" i believe is the vent to air, and those hoses connect to NOTHING... Someone correct me if im wrong please, but im pretty sure thats how its set up...

[pnwesside31]

Hey all, I'm back with no update and the same old story. I'm trying to ensure I have the right connections again since I went through the carbs 3 times and still the same thing. Does anyone out there have pics of all the carb connections? I know this is lame, but I'm sure there's just some stupid thing that I'm not doing right. Please help..........Thanks.

[pnwesside31]

Anybody with pics please?