dhunt488

iTrader: (4)

Looking for a piston/ rod and sleeve set. Where can i get.

Hoese37

iTrader: (5)

Havent made that motor for a few years now. The factory that made them also burned to the ground.

travertini

iTrader: (13)

There's a brand new never seen fuel techno power .21 on eBay for 150.00 ! Same engine and about the same price as a piston sleeve and rod set !

dhunt488

iTrader: (4)

Will the bo2 set work in it? And dont anything about the techno

Hoese37

iTrader: (5)

No it wont work. The 01 was a Mario Rossi motor, the B02 is an OS based motor.

RMKinWI

iTrader: (15)

The JX B01, B01a and B02 are all OS based engines. The GRP based Ninjas were MR prefix I believe.

It will be very hard to find the 5 port Sleeve that was used in the B01 or B01a engines. But you could replace it with the old OS 3 port sleeve from the Speed VZB, which you can still buy on Amain. The B02 is basically the same as the OS Speed XZB and that sleeve would not work.

Good Luck - The B01's were my favorite engine, it sucks they stopped making them.

Eivind E

No.
MR-21 B01 was Mario Rossi made by GRP/tecnomeccani or whatever they're called
JX-21 B01 and B01A were both OS, based on VZ-B in an XZ-B case but with slightly different timings and B01A had a drilled/lightened heatsink head
B02 was still OS based but based off XZ-B stroke rather than VZ-B.

MR-21 B01 and JX-21 B01 have same timings. B01A is the better engine.

travertini

iTrader: (13)

Isn't the arrow gtr II a copy of the ninja ?

Eivind E

Not really, no.. the sleeve will fit in a Ninja case, but that's about it..
Timings are different and the engine won't feel the same, run the same.

A7racer

iTrader: (7)

Agree with Eivind here tho I'm not sure about the timing between the MR and the JX. But yes, the JX was the best of the bunch being made by O.S.

kyosho28

If you have the os jx21 bo1a,get the arrow gtr p/s/r from ebay for about 80-100$.

dhunt488

iTrader: (4)

I would think if timing not right motor would run lime garbage. Wish there was parts still for this motor. I love it. Was looking for a better rebuild than having it pinched. Prolly gunna get pinched and run it for a minute and buy something a lill later. Thanx for all help guys. Some good info here. And yes it is a jx 21 b01a

dhunt488

iTrader: (4)

Is the arrow gtr a 5 port?

masher81

iTrader: (16)

Running the Arrow Pisto, sleeve and rod with the Ninja crank, crank case and carb is an AWESOME combo.

Yes it is 5 port.

Eivind E

It's not really a 5-port though. Usually this sort of extra port is called a +2.

5-port is usually said if the side ports are split in the middle, so the side ports are two side-by-side, meaning it's a 5-port, as opposed to a 3-port which then only has one really wide port on each side.

The arrow gtr II on the other hand doesn't have any side-by-side port, it has the same port on the side as before, and then it has an extra, smaller hole below the port.

Some manufacturers, for example Alpha, has this on some engines, like their F850 vs their A852. The A852 porting is +2, as it has this hole below, but it's definately not a 7-port.

So as far as that goes, Arrow GTR II is not a 5-port, it's the same 3-port, but with a small hole on the side BELOW the actual port, so it's a 3+2. Still a 3-port!
I don't think there'd be any actual performance increase, but I do think this small hole helps with lubrication of the piston. I'm not sure if the piston actually goes far enough down for this extra lower hole to function as an intake, so as such I figure it only helps for the actual lubrication.