HELP Carburetor !!

[stephen Holden]

Does anyone have an idea please what could be wrong with my bike?

Saturday I was driving my 03 Buell Blast when suddenly the bike quit on me (like it was running out of gas). The bike would not start anymore so I pushed it to the mechanic [mad]. He put a little bit of gas on a rag, placed the rag over the Carburetor and had me start the bike. And sure enough it started. So I left the bike with him and he took the carb out and cleaned it (He said somehow water got into the tank and carb). Next day I filled the bike up with premium and took off, no problems. Then Monday it started missing again. After work i started the bike and it idled fine, when I pulled the throttle however, it would die. So I had to leave it at work where it is still standing now. [sad]

Do I have to clean the carbs again??

Thanks guys, I appreciate your help.

 

[d_adams]

I would try draining the float bowl and catch the fuel coming out of it if possible. Sounds like it may have water in it again, you can see the water pool up under the fuel. Just because you put premium fuel in it doesn't mean they don't have water in the underground tank. Had that happen on my lawn mower this summer, 3 different cans of fuel, all of them apparently had water in them.

 

[user_deleted]

stephen: i've never owned a blast and am no board expert on them but do a simple test that one would perform with this same situation on a carbureted bike: remove the gas cap, then remove fuel line from carb. if you have manual petcock turn it to run AFTER placing line in small clear jar. if vacuum operated place line in jar then crank over motor to generate vacuum. try and drain an inch or so of fuel into the jar. reattach line, let jar sit on table or workbench for a few minutes. the specific gravity of water is greater than gasoline meaning if any water present it will quickly sink to bottom of jar. that is your simple test. if you see water i would suggest either removing tank and completely draining........or leaving tank mounted, draining it, and swab it out with rubbing alcohol or similar drying agent and some compressed air to remove any residual water. if your carb has a small drain screw on bottom you should be able to open it and let any fuel and water drain out of float bowl. try the above and see if it helps.

 

[user_deleted]

hey dean: you and i must have been typing at the same time.

 

[stephen Holden]

Thanks guys. I should have mentioned, that before I put premium in there we had completely took off the gas tank and drained it. After I put gas in, I drove for over 40 miles till it started acting up. So I find it hard to believe, that I got water in there again. Could it not be anything else like dirt or so in the carb? and if it is water, do I have to take the whole carb out again and clean it or just drain the gas and add some fresch?

 

[mmcn49]

>>>Does anyone have an idea please what could be wrong with my bike?

More diagnostics needed. It’s a little unusual to get this much water in today’s ethanol fuel blends. To see if you do have water in the fuel system do the following.

Turn the fuel valve to OFF.
Remove the carburetor float bowl.
Look in the float bowl and see if any water is there. Water will look like bubbles on the bottom of the bowl.
If you see any water you need to completely drain the tank and clean the carb.

If you’re not able to pull the float bowl off the carb put the fuel selector valve on reserve and drain the tank into another container. If you have water in the fuel remove it. You also need to determine where the water is coming from.

 

[captain chaos]

Not real familiar with the Blast but I'm betting you have a vaccuum operated petcock (fuel valve). If the hose from the Carb to the petcock is broken down it can collapse which will cause the petcock to close; IE-no fuel flow. That would most certainly cause the problem you describe.
Good luck. [up]

 

[jetlee]

As the others have pointed out, if it's exhibiting the same symptoms that it did when you had water in the fuel...you probably have water in the fuel again. Do what they said above, I don't see a point in typing it out again.

If there's only a very small amount of water in the underground tank, it can certainly take 40 miles for it to accumulate in the carb to a level that would cause issues.

You only have one carb.

 

[stephen Holden]

But I don't understand, how there could be water in there again. I just drove it one day after I completely drained the tank and cleaned the carb. The bike was standing in the shed and it did not rain and I find it highly unlikely that I bought gas TWICE, from different stations, both with water in it ?? [confused]. So there is really no other explanation to you guys then water?? I mean it sure acts like there is water in it (or air??) but man [mad].

 

[jetlee]

The gas station can have water in their tanks, which puts water in your tank.

One truck fills multiple gas stations. Those stations then add their detergents and additives. The truck that delivered the gas could've had water in it.

No one really knows at this point until you drain some of the tank and open the fuel bowl to either confirm or rule out water as the cause. That is the easiest and first step.

-Edit-
Another cause of this condition is missing the needle jet. Easy to see and diagnose. Remove the airbox cover on the right hand side of the bike. You should be able to look straight into the throat of the carb. See the needle coming down from the slide? It should be going into a little silver thing that sticks up about 1/8". If that silver thing (the needle jet) is not there, that could also cause this.

The piece that is circled in red, make sure yours is there. Ignore the bronze thing sticking up, you shouldn't have one.

if vacuum operated

It's gravity-fed.

 

[captain chaos]

It's gravity-fed.

Fuel is gravity fed but the petcock itself has a vaccuum diaphram in it that only opens when vaccuum is present (bike running). This prevents the flooding that was oh-so-common on older bikes with straight mechanical petcocks. I think that is what he was referring to.

A quick Google search seems to show that the Blast's petcock is indeed old-school straight mechanical. Odd, I have't seen one of them put on a bike for decades.

carry on.

 

[stephen Holden]

The thing circled in red is actually not there, I opened and closed the lid with my hand and all I see is the needle, but the broader thing on the bottom (circled in red) is not there. How can I make it show up?? [smirk]

 

[stephen Holden]

Not real familiar with the Blast but I'm betting you have a vaccuum operated petcock (fuel valve). If the hose from the Carb to the petcock is broken down it can collapse which will cause the petcock to close

Do you know how I can find that hose? Can I locate it without taking anything apart?

thanks

 

[captain chaos]

A quick Google search seems to show that the Blast's petcock is indeed old-school straight mechanical. Odd, I have't seen one of them put on a bike for decades

quoting myself.
No hose on yours, sorry.

 

[jetlee]

You cannot fully diagnose water in the bowl without removing the bowl.

The only thing on the Blast that is vacuum operated is the slide. Even that is up for debate since it doesn't lift on engine vacuum but by the low pressure depression from the air flowing around the needle when throttle is opened. It is not adjustable without drilling the hole larger, which is good for twins (Harleys) but not singles (Blasts).

Read the posts above to look for water.

Also remove your airbox cover (it clips on/off) and look at the carb for the silver piece I posted about, above.

 

[stephen Holden]

Well, like I said, the silver peace (needle jet) is not there, what do I do now? apparently the needle jet used to be there, cause it used to drive fine. And the mechanic working on it sunday did not mention anything about it either. [smirk]

 

[jetlee]

Sorry, I missed your comment among all the vacuum discussion.

The silver piece is absolutely needed. He may have installed it upside down.

Take it back to your mechanic.

Show him these pictures:

 

[stephen Holden]

Since he used to be a mechanic and now is an unemployed alcoholic, I think that is quiet possible.[mad] But how could I have been driving for 40 miles until that happened [confused]

Thanks for your help

 

[jetlee]

I don't know how you managed to drive at all without that piece in there.

Unless he did install it correctly, but didn't tighten it down, then it was in place until it vibrated loose and fell into the bowl.

Your bike idles because of the idle fuel circuit. As soon as your crack the throttle, it starts using that needle jet assembly for fuel. If the long bronze part was loose, then it's likely that it vibrated out and the entire assembly dropped into the bowl, which would cause your symptoms.

Either take it back to him or open the bowl yourself.

It's not difficult to do yourself. Here's a how-to video I made:
http://buellridersonline.com/forum/vbtube_show.php?tubeid=19

 

[stephen Holden]

cool thanks, but I have to log in to see the vid?