Ok so i put the roto start in and i turn it over but it doesnt like to turn over alot
Maybe itll turn the engine over once or twice every 30 seconds or so..really bugging me
Any ideas?

You one way bearing needs replacement. Usually with roto starts you have to buy the hole backplate. What kind of car do you have?

i'd guess a Nitro MT. probably a T-15? does the shaft on the rotostart still spin? or does the shaft spin, but not the engine? Or, is your battery just dead? (i hope not tho )

The shaft spins but the engine doesnt spin ALOT...sometimes when the battery goes low and the thing is spinning slow itll work good but thats about it and yes its the t-15 with the purple head

Ok, thanks for the extra info, it really helps with diagnosing the problem, since it's hard to tell with your first description. but, penguin was right in this case. you need to get a new One-way Bearing. your lhs probably sells these, or they can order one for you. It should cost about 15-20$, just so you know. my heart skipped a beat when i went through my first one. I thought they were like 2-3$, and when i looked at the receipt, i saw 25$ (Canadian$), i was really suprised.

Haha, well, the one way bearing for the roto start or for my engine?

Ok i see them on the internet..do you think i could buy a pull start for less then 18 dollars at my LHS?

idk, but a pullstart still ahs a one way bearing

the one-way bearing sits on the starter shaft on the engine, inside the backplate on the motor. in normal operation, it locks on the shaft only when it is turning in one direction, which lets you turn the motor over with your RotoStart or PullStart, but allows the starter shaft to freewheel inside. if this gets oil on it, or gets worn out, it will slip on the shaft when it's supposed to lock. sometimes, it will even seize to the shaft, not allowing the motor to turn over on its own, since it is trying to turn the RotoStart.

the only way to get out of using a one-way is to use what is called a starter box. in this case, there is no starter shaft on the back of the motor (where your RotoStart backplate is), there is just a plate that seals the back of the motor. to start the motor, then, you have a box with a motor in it, and a rubber wheel sticking out the top. this wheel sticks up through the hole in the bottom of your chassis under the flywheel, and spins the flywheel to start the engine. This method makes the most sense for racing, since it allows the least amount of resistance on the motor (when running), and therefore the most power. but, this system is more expensive, since you have to buy the starter box and the the backplate, costing AT LEAST 50-60$

So, i suggest you call up your lhs, and see if they have one-way bearings for an hpi T-15. you don't need a new RotoStart, just a new bearing. so, 15-20$ later, you're back playing in the dirt.

Never own a Roto starter and with all I have read about them not sure I ever well. I do not even have one on my Savage. I either have a pull starter or a starter box, which I just got when I got my Hyper 8 buggy. In well over 20 gallons plus I have only had to replaced 1 one-way bearing with pull starters. Now I will not say I have not had pull starter problems but most of them where my fault from pulling the cord out to far.