Hpi baja pinion/spur gear ratios

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The cylinder should have 2 numbers stamped in the base of the cylinder, possibly had to see, but should definitely be there.
All CY and Zenoah cylinders have the stampings, and I am guessing others will have them too.
I can see the CID having much to do with the over all top speed.
The top end RPM dictate top speed, and Many engines are somewhat close i top end RPM, it is all in how fast they achieve it, or how much Power it produces on the way up.
 
image.webp
That's a picture of the numbers I am seeing are they correct or is it meant to be in a different spot .
Cheers
 
With that marking, it is Not a CY, or a Zenoah engine.
My guess with the mark looking like that is Rovan, but I am not very up on clone engines.
The ones I did mess with back when clones first started coming around were all lesser quality, and had considerably less performance than the CY / Zenoah engines.
Maybe someone who is more up on the clone engines can confirm what you are seeing on yours.

In this case my best advice is to buy a new engine, preferably a Zenoah.

I just took this photo to show you where the markings are & what the Normally look like.

DSCF8599_zpsg2frol6n.webp
 
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Instead of buying a new engine would it be worth buying a top end kit instead? So do you think that the performance of the high speed it caused by the engine more then anything else. It wouldn't be the carb or the clutch or the cdi would it? And lastly the carb is a walbro is that the original hpi one.
 
Walbro is stock for HPI, which used to be CY, and now is KingStar.
Most of the time the clone engines have a Non Walbro carb., and they are horrible when it comes to performance.
Most if the time they can be detected by having a metal inlet & outlet where the fuel lines go on.
Cylinder port timing is also a factor in lost performance.
Someone will have to chime in that understands what engine you have, and if adding a CY or equivalent cylinder is possible.
Most of the time it is, but when you can purchase take out engines for the price you see in the link I will provide here, it is very hard to tell you to use what you have now.

KingStar
http://www.largescalerc.com/26ccnewtakeoutmotorfrom2013hpibaja5bor5sc-bykingstar.aspx

CY
http://www.largescalerc.com/23cccymotorwithclutch-black-1-1.aspx

This is a Very reasonable Great upgrade engine from CY in a 2 bolt head.
http://www.largescalerc.com/285ccgp290motorwithclutch-black.aspx

Here is a Great option in a 4 bolt cylinder head CY model.
http://www.largescalerc.com/285ccgp290motorwithclutch35hp-black-1.aspx


Now consider the price you will pay for a cylinder kit, and remember that your lower engine already has wear on it, and you are unsure how much.
For not a whole lot more than the upgrade, you can have a brand new Complete engine, that you know is going to do very well for you.

I guess that the choice is yours, and as long as you can check the lower part of your engine, and Definitely look at the condition of your clutch as well.
You have to consider that the new engines come with a new carb. and clutch too.
Clutches are a wear item that will also add around 30$ if it needs replacing at the time of upgrading your engine.
 
I think I might get a brand new zenoah G290RC engine from DDM its only 220$ and I might be able to sell the engine I've got i it now. Is that a good engine paired with the pipe I got now?
 
Are those last two engines u suggested modified or something? And would they be as fast as the zen I mentioned.
Cheers
 
G290 is a Great choice !

The G290 is a 28.5cc.

The last 2 links I shared were a 28.5 CY 2 bolt head engine.
And a 27.2 4 bolt head CY engine.

I prefer Zenoah, and I have several of them myself.
The G290 is an Awesome choice, and I am positive that your would love the improvement over what you have now.
 
Oh ok cool how do you break them in, and would that engine pull a wheelie.... And if I want more power for it I can always upgrade the topend plenty of options...
 
The G290 has the largest bore cylinder that will fit that crank case.
You can start to add stroke to them and gain torque, but the G290 is quite strong & should run good for you.
Wheelies are more about car set-up, and traction.
Here is a good example of that, showing a G290 doing wheelies.

This is nearly exactly what you would have, pipe and all, so Yea. ;)
Only a 990 carb. is the only difference ...
 
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