Hey! so i have been on this issue for a couple of days now, I got a 2001 sporty 1200 custom, owned for about 8 months, love it and have done a fair amount of work on it, most recently the stator and rejetting the carb. last week half way through a ride around town, it started to stumble and almost die out when I went past 1/4 throttle. today when I take it out I can barley accelerate at all and it has a little trouble idleing. when it dies when im riding, it acts as if fuel gets cut off, ,and often lets out one loud single backfire. if I try to save it by pulling in the clutch and giving it some gas, it dies immediately, and there is zero throttle response. but it will start right back up and idle ok. as soon as I try to take off, the sputtering starts. i have looked around on the forums but cant seem to find my exact problem! would really appreciate any advice or any tips!
List of recent work done and trouble shooting I have carried out.
replaced stator after it quit
swapped out the 48 jet that was in place for a 45 and re-tuned it (ran great for about 1.5 hours after tuning, that's when this problem started. have taken the carb off since and inspected everything and it all checks out.)
has run great until this issue<
have strong blue spark on both cycles
its getting fuel into the float and the diaphragm in petcock is still good!
pulled cover of ignition module, little red LED flashes for every spark when engine is running, but it does not turn on when the key is turned to run (I have read in other posts that something like that should happen, so I am suspecting the module.)
I have never adjusted the timing it has always been good!
All vacuum lines are good battery connections good.
carb is clean
I am assuming gas in the tank is clean but im just about to drain it, inspect petcock and put new fuel in it. I ride this thing almost daily so I know its not bad gas! possibly clogged filter!?!?! I can hear the gas cap venting after I park it so I know that's good too. pretty stumped with this behaviour and would love some input!
thanks in advance!
Justin
I am by no means a mechanic so don't laugh at me but it sounds like the choke. The last bike I had with a carb did the exact same thing when I would leave the choke on too long. It seems that you did some work to the carb. Could you have accidentally do something to the choke?
I am assuming gas in the tank is clean but im just about to drain it, inspect petcock and put new fuel in it. I ride this thing almost daily so I know its not bad gas! possibly clogged filter!?!?!I can hear the gas cap venting after I park it so I know that's good too. pretty stumped with this behaviour and would love some input!
That right there may be the problem. Since your bike is an older model, it's not unreasonable to think there may be an accumulation of debris at the filter. I've had similar symptoms as your having on a couple of older bikes and that is what it turned out to be. Otherwise you may need to clean the carburetor. Pay attention to even the smallest opening. Have a sewing needle handy to check.
I'm not a mechanic, but my husband (passed away in 1985) was one. He taught me a good portion of what I know.
rufasim, i have aslo just replaced the chik canle and i seems to work good during idle and warm up but i ll take the carb iff and inspect again if drain the tank does not do the trick!
Thanks Bonnie Storm! Ill drain it today and keep you posted!
NORTY FLATZ, Thank for the welcome! I really dont even know how to use these forums and most of the time its from my cell phine so hope im responding right so everyone can see haha, but the plugs are good and wires look in good condition, but might nit be a bad idea to just throw new plugs in��
Just got the tank back on after taking the petcock off and checking the fulter! Looked clean enough, i also deleted the need for vacuum tooperate the petcock so it acts as if it were gravity fed now, tested the flow before i put it on the bike and it flowed no problems. Havent taken it for a ride but i can tell the problem isnt fixed, it is stumbling a littl when i give it gas when idleing and not moving as well, dont think its a new symptom but i didnt realize it was doing it when not under load as well. But i think the choke could be a little suspect, because the carb dose like to pop out, from lean mixture i think!?! Im still playin with it, appreciate the help! Any more tips would be great!
Last edited by ChickinOnaChain; 09-18-2018 at 08:26 PM.
Reason: Multiple posts
With the new jets, you may need to adjust the air/fuel mixture since as you say it seems to be running lean. You will want to re attach the vacuum line or you may end up with a flooded carburetor. (kind of a flow shut off)
When you re installed the carburetor, are you sure you re-seated it properly at the manifold. It is possible there is an air leak in that area. Maybe spray some starter fluid or carburetor cleaner in that area. If the idle speeds up, that might be the problem.
Another thing to consider is perhaps you installed the new jets upside down. Look into the throat of the carburetor and you should be able to see the end of the jet. If it's tapered, it's in correctly, if it's flat, you'll need to re install it.
Yeah the carb is seated proberly, and yes, i checked the jets because i know you can put it in either way but only one way will work. Iv lined up to pick up a used performance ignition module off a buddy at work for cheap, so ill throw that in on tuesday and see what happens and keep this post updated! Thanks again for the help!
09-01-2018, 03:06 PM
sporty stumbles and dies when accelerating
