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weird sounds when gaining RPMS

1401 Views 13 Replies 5 Participants Last post by  EPR
i have a mini harley that i have been drill starting and now all of a sudden when i drive it at around 5-10 mph it sounds high in pitch like usual and how its usually sounds, and when i get even faster, it should get even a super higher pitch, like how one should sound, but now when it hits 15-20 it just drops in sound like a deep heavy sound and when i was driving it,, it sounded like it was gunna die a couple times, but i idled it and it soundded fine, idk wats up? it was like wanting gas? idk but its weird that it just gets deeper in tone when i go faster? help!
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and it doesnt go fast anymore like it doesnt hit top speed
sounds like a carburation problem at high revs.... clean the carb imo... is it cutting out on WOT(wide open throttle)?
Sounds like clogged jets or something like that.
I'm too scared I'm mess it up taking apart the carb! It looks difficult and I won't it leak or somethin?
I'm too scared I'm mess it up taking apart the carb! It looks difficult and I won't it leak or somethin?
there are tutorials.... start by taking it off the motor. there are 4 bolts that fasten it to the crank casing. once that is done come back and tell me, i would be glad to walk you through it. there arent really any parts that can break from you taking it apart.....
Sounds like an airleak or some other internal problem....Good Luck finding it
ok i mean when it idles STRONG and it runs really clean and good but when i get high up in speed it makes that noise? idk but it comes back to idle really nice, i stuck gumout in the tank the other day, but when i stuck the air filter cover back on, that made the noise but i havent stuck it back on and i made the exaust tighter before this started
ok well i took off my engine, cleaned out the carb, (so much easier than i expected), but there was like blake sticky oil and stuff all over the casings and frame idk is that a leak or somethin? i was all in the flywheel case and the outside of the engine. took it out for a spin again and the carb sounded really nice but the engiine still changed in deeper tone when i went full speed and it feels like its holding back from going fast and it trys to go faster but it doesnt
new double valve springs and a cam.
what is a highspeed tuning? and how do i do it? and new valve springs? i mean it was just runnin fine and all of a sudden the next day it just doesnt reach high rpms? dang. i mean it feels like its trying to get fuel and it kinda lungees back and forth sometimes and it still is holding back and making deep tones, is it the exaust? i didnt do the highspeed tuning yet nor the neew valve springs. thanks
If its a 2 stroke and you have oil all over the flywheel the crank seal may have failed. Otherwise i tend to agree with everyone else here thinking your carburetor is done or simply needs the high speed needle adjusted.
could be the coil failing, old spark plug, plugged fuel filter, old gas, etc.

Start with the easiest least expensive things to fix and keep going till you find it.

Yeah, it could be all kinds of little things wrong. How new is the engine?
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