Best motor for hybrid project

No, not an electric/gas power bike. I’m talking about putting a single cylinder motor in my FZR400 chassis. I’m in no hurry because the 400 motor is running great but nothing lasts forever. My racing fund is rather small so buying a new SV (or even a used SV) is out of my range. I’m looking and planning ahead so I won’t have to send a couple of years without a race bike when the 400 motor enters retirement. The 400 is stock right now and if the single cylinder idea proves to be a flop I’ll give the 400 a major overhaul. I’m looking for more competitive classes so building a fire breathing 400 takes it out of one class and makes it somewhat competitive in the others. A single cylinder motor would be allowed in all the 400 classes plus about 3 more competitively. The 400’s best hope is V6LW where a single would have high hopes in Clubman, LW twins and V4/V5 plus a fighting chance in the 400’s classes. Here is what I’m considering so far:

500cc 2-stroke single
Light, cheap, plenty of donor bikes, easy to rebuild, very
simple, WAY strong,
but two-stroke fragile

450cc 4-stroke
Light, performance parts-o-plenty, good power, 4 stroke reliability,
But not cheap, not as reliable as 650

650cc 4-stroke
Plenty of donor bikes, cheap, very reliable, plenty strong,
But heavy, not as strong as other options

250cc 2-stroke
Very plentiful donor bikes and performance parts, extreme light
weight, strong for its size, cheapest of options
But 2- stroke fragile, not as powerful as 500.

I know the TZ250 would be a better frame option but I have VERY limited funds so I need to use what I’ve got if I can. Any ideas and advice will be appreciated. The 400 has a clean title and I have it set up for quick street/track conversion if anyone is interested in a trade for a TZ250/hybrid that is well set up. Thanks in advance and I hope to see you at the track soon.

 

I know this isn't; what you're asking, but Speedwerks makes a bolt-in kit for you to install an EX motor in that frame...might be something to think about.

 

hey

you need to just buy my FZR400/ascott single, it has 17 inch wheels from a gixer 750, front forks from the same, VR100O Tailsection, ducati exhaust, f3 tank, nice air tech body work....

 

The big two stroke motors are fun but require a lot of attention. Your best bet is a big 4-stroke single.

How about an SRX motor.

 

Sounds like a fun project. Good luck!
XR650R engine would be nice but sounds like you can race in more classes with SRX/XT or XR600 air cooled engine.
How about swapping the engine between races? hahah just kidding.

 

XR650R.
Bullet proof, loads of torque, plenty of performance parts available from the desert/Baja racers, very tunable, been around a long time, more reliable than the higher strung KTM big bores.

or

If you really want a challenge, a BSA B50 bored to 88 mm, Ti rod, high comp piston, lightened flywheels, 1-7/8" exhaust, 40 mm carb. Air cooled push rod, 1930's design, British manufacturing . . . at least it's light in weight . . . . I just happen to have several available.

 

Ducnut748,
What are you wanting for the FZR/Ascot? It would be nice to keep my FZR for street/spares use. Where are you? I'm in Ozark, AL. I would love to see any pics you have of it. Thanks.

Greg Gabis,
Would that be my old SRX? I sure do miss that bike.

Thanks for the input. The lighter weight and power of the 500 is pertty tempting but I probably should be looking for a 650R or SRX motor.

 

I'm hoping for a single due to the "unlimited singles" part of the rule in several classes. The EX motor can be made to haul major booty so it is now also an option.

 

i'd say a 450 all day. gobs of power and bullet proof. plus with the dirtbike/supermoto stuff there are tons of parts. you could even go with an older 426 yamaha if $$ is a big factor.

 

Please send pics to [email protected] . What is the motor HP and mods? Still in running condition? I'll start sweet talking the boss lady.

 

Since we's on the subject, anybody interested in a Hawk frame that's been customized to hold an XR650 motor?

 

get a CR500 motor, it'll have the most power, it'll be easy to work on and pretty cheap. AND IT'S A 2-STROKE!!

 

How much bike for how much $$? Pics?

 

How much?

 

Well, I don't have a price or pics yet. Sorry. I guess I really shoulda kept my mouth shut until I had more specifics. I'll try to get it all together this weekend and post some pics.

It's not in mint condition, but it's kinda cool. They made a steel "cradle" that attaches to the frame and helps hold the engine, and they made the frame the oil reserve by closing up all the original holes and putting a filler cap up near the steer tube.

 

Supermono bike

I still have my Supermono bike for sale or trade. A 1988 TZ chasis with a 91USD TZ front end. A 93 XR628 motor. Alot of of work done. Somebody take this thing off of my hands. Bike is located in Leeds, Alabama. Email for pictures. Thanks, DARRYL

 

Please send pics and price to [email protected]

 

600 Rotax........... or KX500 two smoker.

 

FZR400/EX500 Hybrid...

http://forums.13x.com/showthread.php?p=1212157#post1212157