thru carb, it makes a spiff noise and if yu keep cranking it will backfire?have cleaned and blew out all openings and cleaned carb, still wont start engine,just backfires a lot?
2006-09-17 14:52:20 · 7 answers · asked by Anonymous in Cars & Transportation ➔ Motorcycles
Assuming you did not do anything with the engine beforehand and that you problem is really the carburator then do the simplest tasks first and the reasons they should be checked out.
It could be old gas. Drain tank and fill with fresh Super gasoline. Take the time to check plugs. Clean em, and gap em. Next time you take off the carbs check to see the tang angle behind the floats in the gas bowl. The tang is that bent piece of brass metal that controls the flow of gasoline into the float bowl system. If its partly open then only a fraction of the gas needed is tgetting through to the innards of the carb. It's easy to bend and by taking apart the carb it may have been bent accidentally. The tang controls the flow of gas, once the bowl fills to a about 3/4 full the tangs job on the back of the float is to push a metal needle with a pin like end into a rubber o-ring seat. That pressure is enough to jam up the flow until the in-bowl gas gets used up, that allows the float to fall and allowing the tang to open up the gas flow by easing pressure on the needle pin controller.
Next, the choke is a seperate sysytem that makes gas/air mix rich by cable,springs that lead to shaft into the carb body. The shaft can get dirt or have old gas gumm up its works. I got great results by soaking my set of carbs into a bucket of acetone. This stuff will weaken or melt some plastics so gum is gone in a few minutes. But the use of acetone is very dangerous as it burns very easily and its fumes are super strong. If you decide on this make sure you do it outside and away from swparks or flames. Good Luck!
2006-09-17 15:48:35 · answer #1 · answered by ? 4 · 2⤊ 0⤋
If your bike is backfiring through the carb, you're jetting is probably too lean, but, if it's back firing in the exhaust it's probably too rich. Try going .004 richer (larger) or leaner (smaller) depending on where the back fire is coming from. There could be other reasons for it as well, such as carb body wear. When you cleaned the openings, hopefully you didn't use anything other than solvent and compressed air. If you used a wire or some other device to clean the openings, permanent damage to those openings, (changing the size of the openings) may have occurred, in which case, a new carb will be needed. O, another thing......
Also check for any vaccuum leaks from the intake manifold to both the carb and to the engine. An easy way to do this, is after you have it running, spray starting fluid on both ends of the manifold and note for any rise in idle speed. If there is a rise in idle speed, then you know you have a vaccuum leak.
If you recently made any changes to your motor, such as heads, cams, exhaust, more than likely re-jetting would be required.
Good luck.
2006-09-17 15:14:53 · answer #2 · answered by Tom n Tam C 2 · 1⤊ 0⤋
Could be a few things...
-Not jetted right...get a dyna jet kit and play with the different sized jets and gaps on the pin...
-are you running strait pipes? If so, do you have any sort of back pressure like tork cones or small bafles? They will help give you back pressure in your exaust...which is needed for a good preforming bike.
I ha this happen on my sportster so I played with the carb (stock carb) with the jet kits and used thum screws at first for back pressure in my drag pipes, but later added tork cones...oh, I also changed the intake gasket becuase that was the problem...it had a few tiny pin hols in it and once it was fixed it ran good...
So, check that intake gasket (between the carb and the intake) also. I hope this helps you out...
2006-09-17 15:06:38 · answer #3 · answered by DAVER 4 · 1⤊ 0⤋
Sounds like you have the firing order off and its firing on the intake stroke. Why do you think its in the carburator?
Did it run before you messed with it?
If you blew it off while it was still together lots of times you can compress the float and actuly ruen it. If thats the case the float will not close the needle and fuel will not stop filling the bowl. What was the origanel problem? Was it a no start?
2006-09-17 15:02:58 · answer #4 · answered by joeselectric@sbcglobal.net 1 · 1⤊ 0⤋
Always give year, make, engine size and model # when asking questions.
The most commom problem would be the ignition timing is off. Adjust the points and timing if they're adjustable.
2006-09-18 04:32:18 · answer #5 · answered by guardrailjim 7 · 0⤊ 1⤋
it depends on if you have a two cycle or a four cycle engine. it could be a number of things .. if its a two cycle it could be timing if it is a four cycle it could be a stuck valve or timing or a bad cam lobe . thanks good luck
2006-09-17 15:08:59 · answer #6 · answered by chillin 2 · 1⤊ 0⤋
because you touch yourself.
2006-09-17 14:59:42 · answer #7 · answered by Anonymous · 0⤊ 3⤋