65bhp yes you read that right 65 measly,stingy,not pulling skin off custard bastard bhp,the samaritans couldnt help,my tools cowared in the corner of the shed,the dogs nowhere to be seen(it has one of my oxtars sticking out of its ringpeice) and i think i may buy a car.the dyno operater said that it was running ultra rich and wasnt getting enough air which i thought it was anyway but it was off the scale!we tried a run without the airbox lid on with the filter in place and it wouldnt run any sense at all.he also thought there may be an ignition problem too.so what to do?after a bit of thought i modified an fz750 airbox lid as it is much bigger at the inlet and much bigger where it flows into the air filter.i also had some doubts about the staainless downopipes that i picked up from e-bay as they looked so skinny and i always thought they werent right if you get my drift,so i lobbed on the thundercat ones to compare.with just the new downpipes there was a marked difference at the top of the revs and with the new modded airbox top a further improvement was made right thru the range.so armed with these changes im going back soon so if you see a big pall of smoke from a southerly direction followed by a loud bang youll know that ive burned the bikes and my shed and gone and bought a vauxhall astra-happy days

what figures were you expecting?or hoping for?



william

Is that a standard bike or has it had work done on it, i dont think thats too bad if its standard just jet down a bit and it will be all reet, what were you expecting by the way ? you have to do a lot of work for small gains on a 400, if it was easy every body would have big hp ! ( just noticed it the hybrid 600 ) a bit poor then,

between 75-80 bhp which should be feasable from a 94 fzr600 motor even with the smaller 400 airbox.the funny thing is it doesnt feel slow,it will pick up the front wheel in first off the gas and runs very nicely.i spent ages setting it up with different jets and needles(factory pro) and thought it would be making 70-75bhp before i took it to the dyno.im going back armed with a stack of different jets and we will see if we can find the missing horsepower.im going to put the thundercat coils on too.ill keep you posted.other forum members have been getting over 85 so a compression test may be in order if the hp cant be found!

I take it youve checked the valve clearances ?

er no i havent-the dog ate my feeler gauges

i would defo check them mate bit of a ball ache now the motors in ,but well worth the effort. just serviced a friends cbr 600 as it would not go over 75mph, clearances had neerly all closed up, now he thinks i am god for makeing his bike so fast, ( i like him a lot now ) its good for the ego tho !

Sounds like you have got problems. Back in the day the standard fzr600r was kicking out 85 horses at the wheel.
When i had my hybrid tested it showed 87, thats with the 400 air box and completely standard carbs and engine but with a race can.
Id defo check the valve clearances and maybe try standard carbs?
Just done the valve clearances on my 400. All the exhaust valves were spot on but i had no clearance at all on the inlets. Explains why it was a pig to get going, but its spot on now. Fires up first flick of the button and pulls like a train (albeit a little one!)

hi m8 my hybred did 93bhp on dyno with modified 3tj race airbox,full modified r6 race exhaust n rejetted carbs,took it to mallory in july it was scary best of everything now amazing handling n goes like stink.i love it.

I have 87.5 bhp on a dyna pro dyno, 91.5 on a dynajet conversion. My tip would be bin the airbox and stick pod filters on, run 180 jets and zxr750 needles. It also has 41.5ft/lb of torque and from 9-14500 rpm makes over 80bhp. However it is a bit nasty below 9000 with a vicious power delivery and thats coming from someone who race's so on the road it could be a bit of hard work. I am however in the process of making airboxes specially for this conversion, just the bastards in the composit materials bay are really stinjey. I have an M4 race system for a thundercat on mine, however with a scorpion race can on it power delivery is quite a bit smoother but feels slightly down on bhp
Just wondering who you bought the downpipes from as i may be buying some off ebay for £180m for full system?
You could just get a old fzr600 motor and clobber together a 660, that should be 95-100bhp