Revving problem

[Jesta]

Theyre rated at 135 you cant deny that, you just cant, no ifs no buts, as standard thats what they will do, if it did 140 kawasaki would be jumping about singing about how it does 140 but it doesnt, it does 135, modified maybe a touch more, Where about are you? you obviously localish, Im in Yeovil, would be good to meet up with a fellow rider, dont get too many riding mates as theyre all old has beens that come out for the yearly bike meet, then polish and put away theyre bike, and i dont like those sorta people as theyre dangerous to be around cos they dont ride enough to have any skill or safety and theyre not around enough to be out riding with for the other 11months and three weeks of the year. Also if your any good, wouldnt mind having someone help me with my valve shims, paid VJ Suzuki to do them, theyre sooo awfully shite, never goin back, charged 221 quid and only replaced 3 shims when all of them were touching 'eeek' stage. Not a job i done myself, not done anything deep engine, bearings, chains, carbs, electrical and bodywork mods i done but i only got one bike and thats all im licensed for so cant ever have it off road, which sorta means the engine or anything i cant do in a day, doesnt get done.

[zimm]

kawasaki claimed 141mph for the L model, which is just shy of the 14,500 rpm redline on stock 15/45 gearing

my H1 hit the limiter in top on 14/45, which is 135.06mph if we assume the same 14500rpm rev limit, (i suspect the H's rev higher, but the dyno operator wouldnt batter it into the limiter to find out - the clocks are out by ~10% and he took it to 14k according to the dyno) i'm fairly sure it would top out on 15/45 too.

i had 5 points on my licence for doing 143mph through beaconsfield on the M40 (westbound) in 1999 on a 1988 ZX-4, which had already done over 50 thousand miles as a despatch tool. The only mods were a home made air filter, baffle ripped out of the link pipe (it rotted) and a 44 tooth rear sprocket. It took them 7 miles in an 850-T5 to get me to stop. I dont tend to look in my mirrors at 130 + lol

I also recall reading a 400 group test in one of the mags where they couldnt make the zxr400 do LESS than 140, even sat bolt upright, there was a slight tail wind, but in the same conditions the fzr's nc30's and cbr400's were struggling to better 130.. (its what they are geared for) they slated the zxr for everything else, and the NC30 came out on top (as always - why is that ? ive ridden a couple and really didnt like them) i cant remember what mag off-hand though.

im no longer local to bristol, carmarthen these days, if you want a hand with your valve clearances just give me a shout and come over one day .. its only an afternoons work unless something else crops up, or i havent got the right shims here. i presume you mean your 6r ? which model is it ? not that it matters, they are all PITA shim under bucket design IIRC. If its the same shims as the 400 i've got some in most sizes from 2.7mm to 3.2mm

might even inspire me to put my 6r lump back together.

[Jesta]

Yeah its the 6r, G1 1998, shim under bucket.

The zxr400 I had hit 130 after about 1mile, standard airbox + filter, standard can, standard jetting and standard sprox, probably if I had removed the very restricting can id have got it there sooner and maybe faster too, but on a dyno its not a real world measurement as its got no wind resistance, which is the biggest factor on speed and accel reduction. Im not saying it cant be done, but i dont think that a standard could hit that, and youve just said yours was custom airbox and baffleless.

Tell me though, are those airboxes that turn it into a ram air setup any good? Original system is the biggest joke going, ram pipes that face into the back of the filter vent, so stupid that is, if mel was gonna keep the zxr400 passed the end of the year id probably have to have a play with the intakes, hoover pipes are split in a tonne of places, get some custom silicone ones made up, then glass fibre the air intake completely and then run the silicone hoses direct into ports in the glass fibre, reckon thatd bring up the power ratings, hehe

[zimm]

Tell me though, are those airboxes that turn it into a ram air setup any good? Original system is the biggest joke going, ram pipes that face into the back of the filter vent, so stupid that is, if mel was gonna keep the zxr400 passed the end of the year id probably have to have a play with the intakes, hoover pipes are split in a tonne of places, get some custom silicone ones made up, then glass fibre the air intake completely and then run the silicone hoses direct into ports in the glass fibre, reckon thatd bring up the power ratings, hehe

stock system isnt supposed to be ram air .. its just cosmetic and may provide a little fresh air to the airbox, but certainly not under any pressure.. the intakes are in the wrong place for a start.

you can remove the snorkel/trumpet thing from the airbox to free it up and fit bigger mains to compensate, thats worth a few hp, most (all) of the ramair kits available are designed for race bikes and consequently wont really accommodate an air filter, so not really recommended for road use. They are mostly of the type that fully encloses the carbs and have a scoop running under the headstock to the nose, which means your coils need to be relocated elsewhere and the radiator modified or mounted lower down.

i guess they work, racers dont tend to fit stuff that doesnt and most of the quick zxr's have them fitted, however under ~70mph the ram-effect is pretty much nill (any benefits in this range are down to them being very free flowing) and really, you'll need time on a dyno with speed controlled fans to set them up right, there's the potential for running dangerously lean if its wrong.