Kiroritz 440/21& 440/22

[Popcorn popper]

Can anyone tell me the difference in these two engines? Is the porting the same on both? Is the /22 just cdi equipped with different stator or are there more differences? Thanks Steve

[Matt]

The porting was different. Not all the /22 came with CDI. In '74 they had points, and in '75 the JDX/800 came with points but got updated to CDI. By '76 the Cyclone version came with CDI.

[Popcorn popper]

Matt I have a bad stator in this 22 motor. The 21 seems good compression and the point system seems to work. Am I better off to get cdi stator fixed or put this 21 in. The cylinders are saying 120 per side. Im going to rebuild one good one so not sure what to do. The serial number on one is 030710m. 9month 74. The other is 03158om 10/74

[Popcorn popper]

Would the 21 be compatible with 22 pipe?

[Matt]

It sounds like you can use the /21. Or you can buy a rewound stator from Hewtech to put in the /22. Exhaust shouldn't be an issue.

[Popcorn popper]

Another question Matt. Do you guys use stock metal reeds or update to carbon fibre? Thanks for Help

[400brian]

The /21 is a different engine, not much interchanges with a /22, and it was used only one year. I am not sure if the tuned pipe will bolt up or not. I am not sure if the exhaust manifolds will swap either. You would have to try that out. Note that the /21 uses short reach plugs.

[Matt]

I don't know anything about replacement reeds. I'm sure someone has used aftermarket but I've always used the originals.

[Popcorn popper]

I would imagine the fibre reeds would offer some throttle response and maybe a smidge in power increase. Just have to see who can cut them.

[400brian]

I think there are some of the guys that have tried the modern reeds, successfully as far as I know. I believe they were claiming better off the line.

[Popcorn popper]

Ok thanks 400Brian. Just mulling ideas around. Still looking for crank I’ll know more tomorrow. Northern Crankshaft said they could fix bent rod likely have parts on shelf he claimed.

[400brian]

Awesome. I personally know guys who have had work done there, and they were satisfied.

Let us know how it turns out.

[Popcorn popper]

Update again lol found another/22 engine. Turns over good but one cylinder down. Guy wants 350 whole sled. Little high but hopefully better than what i have.

[HoosierDeereMan]

The main difference that I'm aware of between a /21 vs /22 is the connecting rod piston pin dia. /21=16mm pin and /22 is a 18mm pin. For some reason I'm thinking the /22 may have an extra boost port in the cylinder.

Troy

[Popcorn popper]

I pulled both apart. The /22 has 5 intake ports and /21 has 3 ports. The 3 ports are a little bigger but the 5 port must offer more area. Interesting engines for sure.