strange idea

first disclaimer, i'm 1/2 way through a bottle of bonded beam

question, would a kx500 2 banger engine fit into a zxr250 frame?

got a mate with a zxr250 with a rooted motor, and trolling ebay has given me evil ideas . . .

Use a large shoehorn ...

Um no...

You can make almost anything fit into anything. Ide give that one a try.

It would fit no problem. Just have to knock up the engine mounts and make sure the motor sits in the right spot for the chain ....may have to use an offset sprocket.

I have an old ZZR250 aluminium beam frame tucked into the 4th, it is waiting for a KLX650 motor to get dropped in there....

It would fit no problem. Just have to knock up the engine mounts and make sure the motor sits in the right spot for the chain ....may have to use an offset sprocket.

I have an old ZZR250 aluminium beam frame tucked into the 4th, it is waiting for a KLX650 motor to get dropped in there....

Youd do better with putting the zzr wheels on the klx...

Same deal with the kx500. Put the road wheels on the dirty.

It would fit no problem. Just have to knock up the engine mounts and make sure the motor sits in the right spot for the chain ....may have to use an offset sprocket.

I have an old ZZR250 aluminium beam frame tucked into the 4th, it is waiting for a KLX650 motor to get dropped in there....

Youd do better with putting the zzr wheels on the klx...

Same deal with the kx500. Put the road wheels on the dirty.

I don't want to build a motard mate - I want a track bike with a big >600cc one-lunger. Huge difference. Motards are good fun alright but not what I am looking to build. Something a bit like this just for track days.......





I already have most of the bits that will fit onto the ZZR frame, it is the right specs for a big old 650cc KLX motor as far as the width between the frame spars is concerned.....just need a donor motor for the right coin.

Some people have way too much time

I was only just recently thinking of putting a pre '91 CR500 engine into the CBR400 that Leanne blew up to race in the Supermono class at St George and in Period 6 in PCRA.

I think a KX500 into a ZXR250 would be awesome fun.

I was only just recently thinking of putting a pre '91 CR500 engine into the CBR400 that Leanne blew up to race in the Supermono class at St George and in Period 6 in PCRA.

I think a KX500 into a ZXR250 would be awesome fun.

It would be a beast but,you would be better off rebuilding the 400 and racing that. The biggest problem with putting a cr500 motor in will be the vibration.

sorta like this, sorry it seems to have been shot on a potato! but it seems not to be too bad with vibration


but i want to use an alloy modern frame!

I was only just recently thinking of putting a pre '91 CR500 engine into the CBR400 that Leanne blew up to race in the Supermono class at St George and in Period 6 in PCRA.

I think a KX500 into a ZXR250 would be awesome fun.

It would be a beast but,you would be better off rebuilding the 400 and racing that. The biggest problem with putting a cr500 motor in will be the vibration.

Where's the fun in just rebuilding the 400? For me to fit on the 400 either way I need to modify the subframe and raise the bars a lot, so it was more of an idea rolling around in my head than a plan.

I was also wondering if it would be easier to put the forks and swingarm off the CBR onto a CR500 frame?

The hardest part to either idea is finding a 500 two stroke cheap enough to play around with.

Andrew Palmer used to race a cr500 with the pcra with just some flat bars and he put 17 inch rims on it, that's all you would need to do and get someone to set up the suspension accordingly. He put lots of big bikes to shame

.....Andrew Palmer used to race a cr500 with the pcra with just some flat bars and he put 17 inch rims on it, that's all you would need to do and get someone to set up the suspension accordingly. He put lots of big bikes to shame....

I remember that bike - we used to call him 'Chopper Squad' because the bike sat up so high in the air compared to all the other bikes in his class !! It did go really well though.....he must have done a bit of work to the gearbox to get the ratios sorted out for roadracing.......

Vibration can be sorted out easily enough with bushed rubber mounts.