just a quick question. ive seen ads for chips to tweak the k motors engine management systems, for the 16v engines, im not particularly interested in more speed, but was wondering if there was such a thing for the 8v k motors just to clean up or more likely smooth out the fueling. a bit more in the mid range might be nice. but having never seen one for the old 8v k series bikes i wondered if anyone had ever seen them for sale.

I haven't seen any advertised for many years and if memory serves me correctly comments like "why did I bother" were the normal after fitting them.
There are many more effective ways to get better performance. There is a thread started recently about fitting K1100 throttle bodies which made things a bit better.
4 deg more advance gives better bottom end performance. There are plenty of things to play with.

Yes, K Freak is correct, advance the timing at the HES (inside the front right engine cover). Mark it where it was originally using a sharp scriber, then loosen the screws and turn towards the direction of rotation (advance). I moved mine the maximum amount on my '88 RT, it ran smoother, most of the vibration at around 3800 to 4000 rpm vanished and the engine still started fine (no kickback). Make sure the throttle bodies are properly synchronised for smooth running down low. A different exhaust will not increase maximum HP but I found that my Motad system gave a nice little hit around 3500 rpm, as well as sounding lovely and slightly raspy above 4500 rpm. It also saves about 4 kg's in weight. Run the engine on premium unleaded or 98 RON if available, don't run 91 unleaded with the timing advaced or the engine will ping and piston damage can result. Run only standard timing if only 91 RON is available.

good to see your still calling in dennis ....with alwys good advice ....cheers mate !!

At least 2 of 3 times a week Charlie. Always with a view to helping solve a problem or offffering advice to make life easier for like minded people. The K12 does have its roots in the K100 after all. I still miss the 'ol girl, lots of fun to ride briskly among newer bikes. Cheers, Dennis

Yes there were chips that offered small changes to the mapping for the 16 valve they are not available for the 8 valve due to different electronics. That said the chip is not the limiting factor in tuning a K.
Regards,
K-BIKE

K-Bike that is an interesting final statment. What do you reccon is the limiting factor in tuning our 8valve K bikes? is there merit in changing things like injectors and fuel pump pressures etc? or is it the cams that may prove to be part od a matched pair in improvements? I have noticed on you tube that none of the mofdified bikes have as yet managed a Kawasaki type howl from their exhaust's the whom whom sound or is that tyed to the four separate engine pipes going into the muffler that does that. cheers Keith

lol keith you should hear the stayintune ....verry remiiscent of early z900 s......but yes cam timing plays a big part and like so many engine producers are de tuned for reliability and longetivity ,,,,,have you seen the wear limits of the k100 rings .....almost acceptable and i dont see really aggressive cams mentioned anywhere but maybe our day is past for hot mods ...standard cams in the toyota are 220-230 degrees about ...but i have 270 degree cams (race track.spec go out to 310 degrees )...and the difference is amazing ...so much more torgue when you reach about 2500 revs (almost doubles ) from standard ....but low end torque suffers so they produced a longer stroke in the verry next model, got it all back .



hey i just got "stone" the movie ...so z900s will be roaring around my lounge room tonight .....turn it up !!!!yeehaaa



yeah so im a mug lair ....deal with it !!!! giggles

Charlie the staintune I have must be an early one it has the 4 engine pipes going into the muffler same as the origional but round. Once fine tuning of the existing e/l components are performed and then more is sort then that is when I would expect the more intrusive engine mods and engine management mods would come into play. Joining up here I fully expected to hear about lots of mods such as cams and upspec pistons etc but not so. A different type of upgrade has come to be in the 1100 T/bodies mod though, and I am seeing the start of dissatisfaction with the current heat management for the hotter countries. That is where I am expecting to see results. Me I am thinking of a wider radiator with the centre taken out to promote airflow to cool down the innards between the still air box and the cold air filter and to flush the engine's radiant heat. Bushyintas has shown that there is a great way to alleviate some of the latent heat in the tank to injector fuel flow. Also If I was chasing mods it would be for a fatter midrange and better fuel economy plus smoother running all part of the finessing of the machine. and aint stone really the business in 70'smanship, not to mention just alittle angry as a movie, all part of the protest mindset - groovey baby. - Keith

hmm same here with the staintune keith ...but it definatly is a lot louder than the quiet standard exhausts ...and has that note that gets heads turning ...i love it ....yes it isnt like the extractor style and not the throaty roar that modern multies exude but i can certainly hear the promise of such if one were to do a little cutting at the collector and fix that all up a bit more and then put a erm quality noisemaker on the back .

from twbs experience with the 1100 throtle bodies, yes they do make a difference ...he also swapped out the injectors for bigger ones

i have heat mods im dieing to try. one of which is to redirect air up into the under tank area ...for which i have made a mold for fiberglass attachment just in front of the radiator on the front radiator fairing section .......

but the big mod i have planned is to remove the airbox and design a narrow under tank frame enclosure only about 4 inches thick , reverse the afm and get some air from the side of the radiator where it currently is but more or less diectly up to the front of my contraption and air out from the rear of it into the plenum ...

this should give at least another 4 or 5 inches by 6 inches hot air flow down low and away from the rider as well as a little more radiation insulation from all that heat in there, that is currently directed towards the riders legs because of that airbox it currently has to go around , just have to figure out the air filter setup .

the movie was great but not what i remembered but then again i was young and dumb when i first saw it ...nothing else mattered for me but bikes in those days ...crikey 35 years ago

The K is in a relatively mild state of tune especially the touring versions that went round the US the so called California spec engines. The RS has a mildly more aggressive cam timing but it is the old story with engines these is a lot one can do if one is prepared to start getting radical. Phil Irving wrote a great book called Tuning for Speed which is still worth reading. There is nothing inherently different between our K engines and a car engine all the tried and tested mods like head work, valve work and improving the air flow through the engine all will make a difference. The one way to get a huge boost in performance of course is to fit a turbocharger. There have been a number of quite amazingly quick K's after a turbo has been added.
Regards,
K-BIKE

K75cster wrote: Me I am thinking of a wider radiator with the centre taken out to promote airflow to cool down the innards between the still air box and the cold air filter and to flush the engine's radiant heat. - Keith

Keith if you want a more efficient radiator an early model K100 radiator has a 3 row core as against the 2 row one that the post 85 Ks have.
There is presently one on fleabay.Oz for $125. That is a bit expensive but they come up fairly often. You can tell them by the extra row at the back of the core where tha later ones have room for the extra row but it isn't fitted.
The one thing I always say with more power is that the more that goes in and the bigger the bang means more out.
Quite a bit could be gained from the Ks by increasing the comp ratio up to about 12.5 - 1 but anything over that will cause detonation problems somewhere in the rev range and nicasil bores don't like detonation one little bit.
Getting rid of the rev limiter especially on a K75 can produce quite a bit of extra go as it cuts the fuel injectors well before the peak is reached.

God one K-Freak I wondered why the book said 2.5lts K75 and 2'8K100 because they looked the same sixe but never twigged to the tripple core--explains all. k100 owners could go up alittle in compression by fitting K75 pistons Mine are 11.2 to 1 from memory. I have a K100 radiator in the shed as I've presently pulled the K100 apart to repaint the frame part of a long term rebuild. Charlies mods for the radiator sound great, I had looked over the possibility of reversing the still airbox hook up the afm and lay it up alongside the injectors and put a filter infront of that, leaving the whole side of the motor free to expell the hot air, still dont know if that would work. Hence the consideration of a cold air entrance through the radiator centre. Charlies Idea of a front bib to deflect air under the tank makes alot of sense. K-bike the turbo bike with the stone bikini fairing does look fantastic, though I have read tuning for speed (a mates book) I figure much has already been done. I would though still try to find the little things that suit my riding style which is to run the fat of the midrange and operate the controls with simpathy to smootness and economy. The K100s I've rode tingled alittle and I was surprised to find the front engine mounts ruberised and not the other three. Seeking the rta approval to add rubber gearbox mounts and the alternator mount would I reccon pay dividens. Anyone know of that happening???- Keith

It is only the early K100 that have the 3 row core. Up to early 85. The extra capacity is mainly from the extra cylinder.

Ah didnt think of that. mine is a 9th 84 rt model I will go check it out. Keith

Hi I checked out the radiators today and K=freak you are correct I'm amazed I didnt notice that earlier. Taa Keith

One thing to be mindful of when doing any camshaft work is not to let the manifold vacuum get too low as the L-Jetronic injection doesn't like that.
I have been meaning to have a talk with Ivan Tighe who used to do all my camshaft work many years ago and see if the old Kawasaki profiles would go on a K series cam. We used some fairly mild grinds and got good HP increases out of them.
Even just modifing the cam sprockets so you can vary the timing a bit works well. It's amazing just how much extra you can get from an engine by a little tweak here and there.

Hmm Manifold vacumn that would cause kaos as I was thinking how nice it would be to have a rumpety rumpety cam like the old Minies used to. 30/70 I think they were. and its a shame the likes of the mini dont frequent our streets with that marvelous sound anymore. oh well better think more "behave my self" than "lets menace society"