YZ 250 EFI

[2T Institute]

It's a blue sky/clean sheet project, with no corporate constraints why not use the best possible design. Non water cooled cases is 1980's stuff.You might need to redesign the primary drive gears for the crank and clutch shaft being futher apart. That is free HP and will make much more stable temps for EFI.

[Stusmoke]

This frame is a DT / MX 360 frame not Kawasaki ( they were bad frames ). The engine compartment has been shortened 40mm with the swing arm lengthened 40mm. Engine is 40mm further forward. Forks are TZR 250 ( 39mm Dia ) units with race tec valves inside. Custom tripple clamps. Rear shocks are modified TT500 units. So for what it is the Bighorn handles ok. Rear shocks are still a little hard, as 2T pointed out I should change them. Biggest problems are weight and rider.

When you say weight and rider do you mean the weight of the rider? Whats a bighorns capacity anyhow?

[Uniflow]

Originally 346cc or something. Now about 351  I think, slightly longer stroke and a bigger piston. I joke about the bike and I weighing in at a 1/4 of a ton, I bet I'm not too far off. The bikes a fat pig but then some might say so am I.

[Uniflow]

2T, ok you win, easy to change as my gearbox is a little further away from the crankshaft due to the intermediate gear / balance shaft  ( engine runs backwards ). Just for you I'll change it.

[Jeram]

really?

if so thats pretty sweet


An idea for you Neil,you should pop a 24/7 reedvalve on the reed cylinder that you making.

Would be very interesting to compare 24/7 valve to variable disc timing
looks fairly simple to make yeah?

[riffraff]

Uni, you're starting to repeat yourself

[Stusmoke]

Uni, you're starting to repeat yourself

Yeah first you're weighing in at 1/4 ton and now you're repeating yourself? You must really be getting on

[2T Institute]

2T, ok you win, easy to change as my gearbox is a little further away from the crankshaft due to the intermediate gear / balance shaft  ( engine runs backwards ). Just for you I'll change it.

whoever ever buys one will be the winner

[Uniflow]

There we go, weighed both, rider and bike. Bighorn at 121 Kg  with about 1/4 tank of fuel.
rider, 110 Kg, full of fuel. About what I thought.

[Stusmoke]

There we go, weighed both, rider and bike. Bighorn at 121 Kg  with about 1/4 tank of fuel.
rider, 110 Kg, full of fuel. About what I thought.

Thats not so bad. Poor little bighorn motor really is pulling almost a quarter of a ton. It sounds worse when you say it like that though.

[_X_]

back off the fat people you twiggies.

[SachsGS]

 

[evo550]

back off the fat people you twiggies.

Yeah!!!!
He might be fat, but you guys are ugly...and he can diet, but you can't fix ugly " title="Roll Eyes" class="smiley">

[2T Institute]

back off the fat people you twiggies.

Yeah!!!!
He might be fat, but you guys are ugly...and he can diet, but you can't fix ugly " title="Roll Eyes" class="smiley">

And when you try to fix ugly .....................

[Uniflow]

 Can you read this? Getting a little off track here, but this is the original sales brochure 1973 F9 bighorn, when they knew how to bull****,       I mean advertise!!