Uneven Acceleration

[slimshady]

So I'm new to the motored-bike world, and with my first build finally finished, I was disappointed to find that my bike does not accelerate smoothly. When i pull back on the throttle, the engine doesn't seem to accelerate, and suddenly the speed increases. Then, when I try to decelerate, the engine doesn't slow at all, it just maintains speed

Another question I had was how do I set up the motor so that when i start it up, I don't have to use the choke? Is the choke necessary for startups? Mine doesn't seem to want to start without it.

Thanks in advance

 

[motorpsycho]

you only need the choke when the air is cold. 9 times out of 10, i can start mine without using the choke.
there is no way to "set the engine up" to start with or without the choke. some engines need to be choked to start, some don't.

your acceleration problem could be an air leak at the intake tube where the carb. goes on.

 

[slimshady]

I guess I have an issue then because my engine rarely starts and when it does, it grunts at random intervals giving a little power and then dies out. Any suggestions? Also, I am using synthetic oil but its not for 2 strokes. I don't know if that could be an issue...

I checked the intake tube and it seems fine. Another question I had was how much play should I have on my throttle? I think I have too little. How do I fix this if there is too little play?

Thanks

 

[motorpsycho]

I guess I have an issue then because my engine rarely starts and when it does, it grunts at random intervals giving a little power and then dies out. Any suggestions? Also, I am using synthetic oil but its not for 2 strokes. I don't know if that could be an issue...

I checked the intake tube and it seems fine. Another question I had was how much play should I have on my throttle? I think I have too little. How do I fix this if there is too little play?

Thanks

if you are using synthetic motor oil and not 2 stroke oil, that would probably be your problem.
you must use oil made for 2 strokes, either regular or synthetic....but it MUST be 2 cycle oil.

you should have a little slack in the throttle cable so that when you turn the handlebars left to right, the cable isn't being pulled. this could possibly cause your bike to accelerate while turning, and that's a bad thing.

The throttle cable should have an adjuster on it up close to the throttle handle assembly. it looks like a 90 degree peice of steel tubing with threads, a threaded sleeve and a nut on it. the end screws into the throttle assembly and it has the cable going into it with a threaded sleeve and a locking nut.
loosen the nut and screw the sleeve in (tighten) to loosen the cable, screw the sleeve out (loosen) to tighten the cable. what you will be doing is making the tube longer or shorter depending on which way you turn it, and by doing that it will take up or add slack to the cable.
once you have the sleeve where you want it, tighten the nut against the sleeve. the nut will lock against the sleeve so it doesn't move.

 

[slimshady]

if you are using synthetic motor oil and not 2 stroke oil, that would probably be your problem.
you must use oil made for 2 strokes, either regular or synthetic....but it MUST be 2 cycle oil.

you should have a little slack in the throttle cable so that when you turn the handlebars left to right, the cable isn't being pulled. this could possibly cause your bike to accelerate while turning, and that's a bad thing.

The throttle cable should have an adjuster on it up close to the throttle handle assembly. it looks like a 90 degree peice of steel tubing with threads, a threaded sleeve and a nut on it. the end screws into the throttle assembly and it has the cable going into it with a threaded sleeve and a locking nut.
loosen the nut and screw the sleeve in (tighten) to loosen the cable, screw the sleeve out (loosen) to tighten the cable. what you will be doing is making the tube longer or shorter depending on which way you turn it, and by doing that it will take up or add slack to the cable.
once you have the sleeve where you want it, tighten the nut against the sleeve. the nut will lock against the sleeve so it doesn't move.

Thanks. So, until I can buy 2 stroke oil, is it ok to leave that oil-gas mix in my bike? I wont run it but can it sit there or will it screw something up?

 

[motorpsycho]

well, as long as you don't run it, it won't hurt anything.
But I would drain that gas/motor oil mix out of there, and start over using a good quality 2 stroke oil.
you should probably srat out with a 20:1 gas/oil mix, and then adjujst it from there.
I run mine @ 32:1, but my engine is broken in already...not sure if yours is broken in or not.

 

[slimshady]

I am also having trouble idling. When I pull in the clutch to disengage the engine, instead of reving slowly, the engine revs extremely fast and starts shaking the whole bike. Is there any way to slow this? Ive tried the screw.

 

[Deleted member 12676]

Sounds like you either have an intake air leak or you need richer jetting.

 

[A_FITZ]

I am also having trouble idling. When I pull in the clutch to disengage the engine, instead of reving slowly, the engine revs extremely fast and starts shaking the whole bike. Is there any way to slow this? Ive tried the screw.

Is the bike running and taking you where you need to go?

Engine Revving Fast, you mean upon start up from a roll, it jerks? Mine does that too from a rolling start.. they just have high acceleration. Slowwing it? ask these guys lol..

And if your moving fast, the bike will vibrate going over 25mph. It sucks. I know.

Also my bike wont start or run until I have the Choke lever adjusted just right where the bike wants it.., hair adjustments will help.

Other then that im just an expert compared to these guys.., I just know that setting up the choke right matters allot, especially in the cold.

 

[slimshady]

Now my acceleration issue is gone but the chain keeps coming off. Anyone else have this problem? My hypothesis is that the chain is way too tight on there. Could that be the reason? Thanks