Dizzle123

Member
Mar 20, 2007
10
0
Ok heres the story i have a 2002 xr 100 im trying to sell it. Ive replaced the spark plug, bought a NEW Carb, cleaned the airfilter got all the bad gas out of the gas tank and put new gas in, and also changed the oil. But i can not get it to start the only time it ever fires is if i put a lil gas on the spark plug. But it will only fire once then cutts off. So any help would be awesome i really need to get it fixed without paying lots of money to get it to the shop. Thanks!
 

Dizzle123

Member
Mar 20, 2007
10
0
well i know for a fact that from the tank to the carb its getting gas.. soo im not sure.. just hope its nothing to pricey
 

Dizzle123

Member
Mar 20, 2007
10
0
ya man i took out the plug and kicked it and it sparked a little on the exhaust pipe.. my dad said that little spark was enough though.. but it is a brand new spark plug from the honda dealer. so i dont know
 

mmz77

Member
Oct 15, 2006
435
0
Huh...? Thats a bit weird there, maybe your coil needs replaced. Thats all I can think of right now besides the fact you might NOT be getting enough spark. This leaves me clueless
 

Dizzle123

Member
Mar 20, 2007
10
0
well it only fires once when i put gas on the plug. but when it fire it revs then i try to gas it and it just cuts off. im confused
 

mmz77

Member
Oct 15, 2006
435
0
Heck, if you replaced the carb it should be running just fine because it should be getting gas to your engine. Somewhere this is restricted... I would check your carb if your getting gas to it, maybe the fuel/air ratio is completely off or something. I'm trying to help but I am just as confused as you are...
 

rmc_olderthandirt

~SPONSOR~
Apr 18, 2006
1,533
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Dizzle123 said:
well it only fires once when i put gas on the plug. but when it fire it revs then i try to gas it and it just cuts off. im confused


Any gas you put on the plug would be gone after the first revolution. If it revs up then it must be getting gas from the carburetor.

Perhaps there is something else going on. Go through the same motions that you would if you were putting gas on the plug except don't put any. That is, take the plug out, leave it out for the same length of time and then put it back. Kick it. Does it start rev up?

If it does, then I would suspect that things are way too rich. When you remove the plug you let enough air into the cylinder to lean it out so it will fire once, then it has enough heat to continue to run for a bit before it bogs down and dies again. From there I would approach it on the basis that the engine was flooded.

Is this a two stroke? Perhaps you have some gas down in the crankcase which is really messing things up. A puddle of gas in the crankcase will keep the engine way too rich to run and the only solution is to get the gas out, either by letting it evaporate or pulling the plug, turning the bike upside down and kick it over to get the gas to drain out.

If it really is the fact that you added a little more gas to the system that made it fire up then it is running way too lean. The fact that it does rev up would indicate that the main jet is functional, so I would try opening the idle jet some and raising the metering needle a notch.

Rod
 

Dizzle123

Member
Mar 20, 2007
10
0
thanks rod for the post. from what ive tried was that it would only fire by putting either gas on the plug or a tiny bit of gas in the engine and it would only turn over once. but im not reall experienced in tunning carbs and all. so if you could tell me more detailed how to make it leaner and richer, etc.. (by the way its a 4 Stroke)
 

Dizzle123

Member
Mar 20, 2007
10
0
pyrex said:
yeah rip apart your carb and tune it to factory specs.
ya i dont have a manual so i dont know the factory specs. maybe my carb is set up wrong as rod said. im kind of a noob when it comes to tuning and stuff i can only put stuff together haha
 

Dizzle123

Member
Mar 20, 2007
10
0
ok so i went outside. checked plug it was getting ample amount of spark. i put carb cleaner on it in a lil on the enigne and it fired then a second later it died. i played with the carb and couldnt get it to ever fire with out putting something on the plug and engine
 

TimberPig

Member
Jan 19, 2006
859
1
Dizzle123 said:
ok so i went outside. checked plug it was getting ample amount of spark. i put carb cleaner on it in a lil on the enigne and it fired then a second later it died. i played with the carb and couldnt get it to ever fire with out putting something on the plug and engine

If it fires with fuel through the plug hole, then you can eliminate spark, compression and timing from the equation. Your problem lies in the fuel system, likely it is not drawing fuel through the carb. That new carb may have issues, like a plugged valve, or a stuck float, that is not letting fuel into the bowl. Go through the carb, check all the circuits and make sure everything is spotless and functioning.
 

Dizzle123

Member
Mar 20, 2007
10
0
TimberPig said:
If it fires with fuel through the plug hole, then you can eliminate spark, compression and timing from the equation. Your problem lies in the fuel system, likely it is not drawing fuel through the carb. That new carb may have issues, like a plugged valve, or a stuck float, that is not letting fuel into the bowl. Go through the carb, check all the circuits and make sure everything is spotless and functioning.
well the old carb i had on there was having the same exact problem.. if would only fire with gas in the plugand engine.. so im pretty confused haha
 

Patman

Pantless Wonder
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Dec 26, 1999
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Adjust the valves.
 

1BAD250

Member
Nov 21, 2006
72
0
you said the othe carb did the same thing, after you remove the plug after it fires or rev a few seconds is the plug dry or soaked??(if soaked or still wet check your air box for obstrutions or posibly blocked off with somthing)..now if the plug is dry make sure you put enough fuel in the tank if not turn the petcock to reserve,or check that your breather tube on the fuel cap is not pluged up you should be able to suck air threw it easy...also one more option you sure the fuel is not contaminated with water?? check this stuff its all i can think of right now sence you said the same thing happend with the other carb.
 

Dizzle123

Member
Mar 20, 2007
10
0
ya after it fires the plug is dry. which im guessing is nto a good thing.. im going to go check the air tube and see whats up
 
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