Putting a full size 125 or more into a Pit bike project

[Dannylewis27]

Ello all
Now before I start I'd be very appreciative not to get any stupid comments or any grief because they don't like the idea.

NOW, I'm about to buy an Akuma assasin 125 pit bike
JUST for fun
I don't care if they're cheap and Chinese or it will brake
This is JUST a hobby thing

I was wondering about fitting a different engine in it, like maybe a Rotax 123 or 122

I know I'd have to change the mounting bolts on the frame but if I could get it in the frame that would be pretty fun pit bike right??
Or even a bigger cc (just depends on how much room I have)

Has anyone else ever toyed with this idea?

Regards.[/list]
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Derbi senda R, 03
Aprilia RS 125 Extrema, 98

[P.]

It might fit, be a pain though.

Binge put a TZR engine into his pit bike.

Why not just chuck a 160 in there?

[rezzin]

What about a honda lump.. 4 stroke 150cc+ would be plenty of fun surely?

[Dannylewis27]

Wehay good answers!

I'm not really sure what engine to put it

My last bike was an aprilia rs with the Rotax 123 and that topped me out at 100mph so my initial thought would be to stick that In

(I know it won't go that fast due to wheel size and aerodynamics bla)
But it would be pretty fuckin nippy right?

I've never owned a 4t before so I'm weary of using one of those?
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Derbi senda R, 03
Aprilia RS 125 Extrema, 98

[P.]

Wouldn't bother trying an RS lump.

Maybe a DT/TZR/NSR engine but for guaranteed fit and ease to work with...

https://www.ebay.co.uk/itm/upower-150-pit-bike-engine-pitster-pro-pitbike-m2r-lucky-mx-yx-150-Mini-mx-/321033378581?pt=UK_Motorcycle_Parts&hash=item4abf149b15

[Dannylewis27]

Realising now aswell that the chain on the pit is on the left
I've not seen The mounting bolt holes on those engines but I know the Rotax is awkward
I spent many swearwords and bloody knuckles with that thing!
____________________
Derbi senda R, 03
Aprilia RS 125 Extrema, 98

[Dannylewis27]

And I don't mind putting another pitbike in I just know that they're downgeared and I want to get most out of it!
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Derbi senda R, 03
Aprilia RS 125 Extrema, 98

[binge]

Dont bother with an Akuma Assasin mate. Seriously.

They dont fall under any 'pit bike' category as such. They are purely a run of the mill Chinese mini-bike.


The good circle of Pit bikes are based upon the Genuine Jap equivalent bike.

Honda CRF50, Honda CRF70, Kawasaki KLX110, Yamaha TTR110.

The Akuma Assasin as none of the above. So even plastics are a pig to get hold of.


The engines are just upright engines. If you must put something else in, the best one to go for is a Yamaha YBR125 engine, as they are a direct fit, but being the real jap thing, they produce more power than the available Chinese engines.
The Akuma engines go right up to 250cc. But they are still as slow as shit.


Go with a pit bike which holds a horizontal engine (Honda C90 style). You'll have a much easier time sourcing upgrades etc.


One of my many pit bike projects:

https://sphotos-c.ak.fbcdn.net/hphotos-ak-snc7/427640_10150553203550606_1870049609_n.jpg

[Dannylewis27]

I was just going for the akuma because I didn't really wanna spend a lot of money
Just buy a little cheap toy and maybe fiddle around with it a bit
I know the cr50 n 70 are a lot more expensive

I'm confused what you mean about the horizontal engines like the c90 when the c90 is like a pitbike engine?

Please explain?

And if you've done pitbike projects before please give me any more advice!?
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Derbi senda R, 03
Aprilia RS 125 Extrema, 98

[sulphur]

I just have to say, that pit bike "project" looks sweet as funk!

Sweet! As! Funk!

[binge]

Okay, here is a genuine Honda CRF50:

Look at the plastics, look at the lay flat engine, look at the geometry.

https://www.procomeng.com/images/model/92_main.jpg


Now here, is a BSE Factory built pit bike, based on the Honda CRF50. It's actually a Stomp ACE50:

Again, notice the plastics, the lay flat engine, and the geometry:

https://www.ridestomp.com/ace50/files/blocks_image_2_1.png



Now here, is an Akuma Assasin;

Notice the plastics which dont match anything, the upright (Yamaha YBR125 style) engine, and the God awful geometry!:

https://i.ebayimg.com/t/Ninja-Assassin-250cc-pit-bike-/00/s/MTIwMFgxNjAw/$(KGrHqJHJDQFCWu))mdmBQsoR9upYQ~~60_35.JPG


And even if you are lucky enough to pick up an Akuma which runs the lay flat engines, they are still dog shite;

https://www.hiwtc.com/photo/products/3/08/52/85231.jpg



Seriously, stick with the BSE or FYM factory makes:

Stomp
Demon X
M2R
LuckyMX
FYM Xsport
FYM Masai
Thumpstar / TerraMoto
FK1 from FiddyParts

A friend of mine has started his own company, manufacturing MonsterPro pit bikes. Absolute top bit of kit, and race ready.


Or if you can afford it, A Pitster Pro.



But stay away from anything like the Akuma Assasin. There was an Orion 250, and a Bulldog 250 too. Both these bikes were on Watchdog a few years ago. Death Traps!





Ben

[rezzin]

The recent akumas (improved frame) are fine for field use but nothing more. Expect to replace clutch and brake levers & both cables after a few months and be gentle with the gears as they seem to be made of chocolate

[rezzin]

Also there is absolutely no point putting a bigger engine in there at all as it will just shake the bike to pieces, pretty sure there only built to do around 40mph on a field.

[Nick__C]

Binge you sicko that pit looks like an absolute monster! How much has that beast cost you all in all?
Is that road legal btw?
____________________
'02 GS 500.

[binge]

It was road legal yes. It's long gone now mate. Broke it down for parts so nobody else could own it.

Put a lot of money into it, but even more in time! Hours and hours went into it. Every last bit was custom made or upgraded. But it needed it to handle the power of the engine.
It had a KTM SX65 front end on it, with a KTM 660 caliper. Billet swing arm, GSXR600 rearsets. Maybe £2.5k in total?


To the OP. If you go for a real pit bike with a horizontal engine, you can just go for a Zongshen 155 engine or something similar. They can be beefed up to around 20bhp.

I've a Z155 in my supermoto track bike, which is hauling maybe 18bhp as it is, I need to have it RR'd when it's all fitted up in the bike.

And I have a 125 hybrid engine which I've built for my wet bike (When I finally get round to building it up), and that has a 140cc barrel and high comp piston, a Lifan 150cc Cylinder head, and a lot of fettling, it's as powerful as my z155 engine I'd say, just a whole load more revvy, and less torque.

And then I have a Lifan (Daytona style) 150cc engine in my Honda Chaly.
That's less powerful, maybe 15bhp, but it's got loads of torque, and can pull the Chaly up to 70mph+.

All my engines below:

Z155 - Roughly £350 to buy brand new - Bolt straight in

https://sphotos-a.ak.fbcdn.net/hphotos-ak-ash3/181394_10151313159070606_1839464991_n.jpg


Hybrid 125 (140cc) engine, cant buy these, but they're similar to a YX140 engine, which are about £200 - £250 to buy new - Bolt straight in: (on the right)

https://sphotos-a.ak.fbcdn.net/hphotos-ak-prn1/154537_10151316513855606_1695581083_n.jpg


And my Lifan 150 (Daytona Style) engine, which is in my Chaly. These are slightly rarer, but can be had for about £300 brand new.

https://sphotos-a.ak.fbcdn.net/hphotos-ak-prn1/546698_10151130231270606_1731733280_n.jpg




Most reliable will be a YX140. Still good for 12/13bhp brand new with a decent carb.

[lukamon]

wonder if these engines will fit in the new MSX. if they do, would seem a bit of a waste to throw away a perfect new honda engine for a yx though
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killa wrote: Im an ass man myself

[Dannylewis27]

I know you don't like the akuma but like I said its just for a bit of fun I'm not going to be racing it or jumping it and its my first pit bike so don't wanna spend loads
Just a little toy
I was just curious how easy it is to fit an upright engine
____________________
Derbi senda R, 03
Aprilia RS 125 Extrema, 98

[P.]

[Nick__C]

Yeah I saw on Kris' facebook wall
Sounds like you've got a proper pit bike operation going on!
How much do you reckon a decent pit would cost all in all? On a scale of akuma addssins being poor to your now deceased 2 grand pit being awesome?
____________________
'02 GS 500.

[binge]

Akuma will be about £200...

£300 will get you a decent second hand Stomp/demon etc.

£500 - £650 will get you a good brand new bike

And for a grand you can buy a fully loaded race ready bike. Or a second hand genuine mini.

[st3v3]