Clean carbs now bike wont start......

[turkeyroll60]

My new ebay carbs are clean and reassembled. I blew through all openings to ensure all air passages were good and put them back on. Major plus is that there is no more flooding out the vent tubes but now the bike wont start. There is fuel as when I prime the carbs a little fuel leaks out the vent tubes. The petcock only work when suction/vacuum is applied. I checked both plugs for sparks with positive results. The stock airbox is sealed and a clean airfilter is properly fitted. Throttle cable has all slack taken out and the idle screw was adjusted through its full range and still no starts. Not even a turn over. The carbs were listed on ebay as coming off of a late 70's suzuki but I'm not sure which model. The only thing I have not messed with is the air mixture screws. They still have the plug from the manufacturer in them. Could be something as simple as that? How many air cooled twins were out there in the late 70's that would require a different setting from my 82 450txz? I am really stumped here.

[Nessism]

Do a proper carb rebuild. Verify the jets and compare against the factory service manual. Replace all the various O-rings, including those on the intake boot pipes. And needless to say, remover the stink'n idle mixture screws after drilling out the caps.

Short cuts are long cuts, and you are taking the long way home.

[turkeyroll60]

These carbs were rebuilt with the good parts off the carbs previously bought with the bike as well as all the necessary orings from cycle orings.com. the pilot jet, needle jet, the jet needle and the main jet all match what is listed in my clymers book. My only option left is to pull out the cap from the air mix screw. I am learning as I go and appreciate those of you who have more experience than me. One day I will be the crusty old vet on gsresources throwing out the advice.

[JimmyR]

Well put! Good response.

[Nessism]

Sorry to bust your chops but you never cleaned the carbs. You need to pull off the mixture screw caps, remove the screws, fully strip the carbs and soak them in carb dip per the rebuild tutorial. Until you do this you are just guessing regarding their condition.

The carb rebuild tutorial is linked in my signature, and Basscliff has a 450 rebuild tutorial too. Use both and after you are done you will be able to move forward with your project knowing the carbs are cleaned properly.

[turkeyroll60]

Ed, I'm sorry for the confusion. I dipped these carbs but I never said that in this thread, I said it in another thread and took it for granted that it was know when I switched to this thread. I have some time before work this morning to get those caps off so I will keep you posted.

[Nessism]

With the mixture screw in place the carb dip can't get though to clean the idle system passages. This may or may not be part of your bikes problems, I don't know, but there would not be all this guessing if the passages were known to be clean. Building a foundation of known system conditions is what maintenance is all about.

Pull off those screw caps, remove the screws, and then consider dipping the carbs again, or at miminum shoot carb spray though the passages and make sure the passages are clean all the way down into the float bowl. Did you check my carb rebuild tutorial on checking the choke system passages? Checking to make sure the pilot jets are open? One way or another your engine is not getting fuel (or spark - I assume you checked that already right?). Check the small passages first since those are the ones likely to be plugged.

[allojohn]

"crusty old vet" indeed, you are a bad man!

Check your float height, it'll never start if the fuel level is too low. The air mixture is not your problem at this stage.

If it's not the float height you will have to break 'em down and dip them properly (again).

[Pendulum]

The carb spec thread at the top of this section, and the tutorial on basscliffs site should have the settings for your mixture screws if your manual doesn't. Download Cliffs rebuild tutorial and Nessisms as well. I used both when doing my carbs, since each one has a couple little tips/info that the other doesn't.

[tom203]

As Nessism said, get those caps off and dip again unless you need practice at carb removal. If it didn't show any signs of starting with "choke " applied, I'd suspect that little hole (for choke fuel feed) in bottom of fuel bowl is gunked up, so make sure you clear it.

[turkeyroll60]

I pulled the caps off and removed the idle mix screws and then broke the carb down again. I immediately noticed the left carb bowl was dry. There was some debris inside the bowl and it was all gummed up. It has been soaking since 8:30 this morning. We shall see. I guess the first dip was not long enough. Thanks guys...the quest continues.

[allojohn]

Dip 'em for 24 hrs - not a second less.

[Nessism]

Fuel tank may have crap in it. Check before hooking up the carbs again or rust will just plug up the carbs again.

[Suzuki mad]

There are times when I admire the patience of senior members on this site. At times they have to be mind readers, clairvoyant even to answer people posts.

The carb cleaning series is extensive to help with issues on carbs. Well written and explains a whole lot of facts of cleaning and getting them going.

Basic of engines and running are fuel, air and a spark. Too much of one or not enough of the other and it wont start.

Old plugs, old fuel, dirty carbs, poor carb boots, dirty air filters, 30 year old wiring give lots of reasons for these bikes not to run.

Try a modern day GSF1250SA or FLO. ECU's on everything, fuel injection and metering, fuel pumps and nothing you can work on unless your an electrician.

[turkeyroll60]

I just pulled the left carb out of its 24hr bath in gunk carb cleaner. I'm gonna take my time rebuilding blowing out all the passages with air along the way. One thing I'm still confused on is my clymer says float height for all models is 25.6 to 27.6mm and the right after it says float height for gs450 models is 21.4 to 23.4mm. The second set of numbers seems too low. Can anyone shed some light here? I am very grateful for this forum by the way, it helps me perpetuate mistake number 11.