i am building a bike at the moment im using a gsxr 400 engine its a gk71f was just wondering if any body can recommend some engine mods to get a little extra cheers from alex

Put a 750 in it ?

Want to stick with the 4 just thought there could be ways to get a little extra from it

Not the easiest engine to tune and can be fragile as well, I would just get it running correctly first then see how it goes.

Well like any engine, you can flow the head and match the intakes to the carb stubs. The camshafts could be reprofiled (Kent Cams ?). You could look for a piston kit (unlikely) or have a look at using parts from another bike and build a hybrid engine, probably with 600 parts. You can look for a free flowing air filter and bitter downpipes and maybe a can.
Building an engine is expensive and having tuning will work out more so ... you'll probably spend about 400-500 for a standard engine rebuild (gaskets, shims, skims, and rings), a head will be £300-500 then you need the carbs sorted out with a bit of dyno time £250 all on a four hundred that can get a bit fragile if it's taken to far.

I'd say build the engine standard first, get it running and reliable. Spend your money on suspension, you'll probably need a rear shock, ask a couple of suspension firms what they would do to the forks. Overhaul the brakes with new fluid pads and maybe lines if needed check the chain and sprokets, use some good tyres.
Any road bikes value is in it's reliability and ride quality first, then you can tune it.

Cheers for the advice ill get the engine running as it should and take it from there thanks from alex

Evilchicken0 wrote:Well like any engine, you can flow the head and match the intakes to the carb stubs. The camshafts could be reprofiled (Kent Cams ?). You could look for a piston kit (unlikely) or have a look at using parts from another bike and build a hybrid engine, probably with 600 parts. You can look for a free flowing air filter and bitter downpipes and maybe a can.
Building an engine is expensive and having tuning will work out more so ... you'll probably spend about 400-500 for a standard engine rebuild (gaskets, shims, skims, and rings), a head will be £300-500 then you need the carbs sorted out with a bit of dyno time £250 all on a four hundred that can get a bit fragile if it's taken to far.

I'd say build the engine standard first, get it running and reliable. Spend your money on suspension, you'll probably need a rear shock, ask a couple of suspension firms what they would do to the forks. Overhaul the brakes with new fluid pads and maybe lines if needed check the chain and sprokets, use some good tyres.
Any road bikes value is in it's reliability and ride quality first, then you can tune it.

HMMMMM!!!! Can i please pull the chickens feathers out!!! Long time mate!!!! I think last time was bike show in london lol.

Want a mental 76a???
442cc piston kit. There is a crank aswell the gives a longer stroke. Heads respond great and you dont even need to raise rev limit to mate in excess of 80 at the rear wheel in fact power peaks very slightly lower in rev range with more torque. And yes it has been done but i'm not going to give away all my secrets.
But i personally love it as a 442cc with sp gearing and 636 front end and thou rear shock.

stripes1976 wrote:

Evilchicken0 wrote:Well like any engine, you can flow the head and match the intakes to the carb stubs. The camshafts could be reprofiled (Kent Cams ?). You could look for a piston kit (unlikely) or have a look at using parts from another bike and build a hybrid engine, probably with 600 parts. You can look for a free flowing air filter and bitter downpipes and maybe a can.
Building an engine is expensive and having tuning will work out more so ... you'll probably spend about 400-500 for a standard engine rebuild (gaskets, shims, skims, and rings), a head will be £300-500 then you need the carbs sorted out with a bit of dyno time £250 all on a four hundred that can get a bit fragile if it's taken to far.

I'd say build the engine standard first, get it running and reliable. Spend your money on suspension, you'll probably need a rear shock, ask a couple of suspension firms what they would do to the forks. Overhaul the brakes with new fluid pads and maybe lines if needed check the chain and sprokets, use some good tyres.
Any road bikes value is in it's reliability and ride quality first, then you can tune it.

HMMMMM!!!! Can i please pull the chickens feathers out!!! Long time mate!!!! I think last time was bike show in london lol.

Want a mental 76a???
442cc piston kit. There is a crank aswell the gives a longer stroke. Heads respond great and you dont even need to raise rev limit to mate in excess of 80 at the rear wheel in fact power peaks very slightly lower in rev range with more torque. And yes it has been done but i'm not going to give away all my secrets.
But i personally love it as a 442cc with sp gearing and 636 front end and thou rear shock.

Hey,
What about one secret then....which crank for the longer stroke Stripes??
Andy