Maintenance & Technical > KX500 Original
New guy needing some info.
stewart:
4 stroker ..im glad to see you putting the thought your putting in to the k5 moter ,,i cant speak for any one else but i have found in the last 25 years of engine work that i should first get a handle on and wring all i can out of a setup then make changes 1 at a time to see whats helping and hurting the combo,,and to get a better understanding of what each move does ...that bieng said alot of effort was made on sizing the k5 at 86 by 86,,the stuff ive work on that was stroke or big bore on the k5 did not make the power of my current 86 86 combos,,and is was not for lack of trying...but i hope you can find something to help us improve if its there , thanks stewart
4stroker:
--- Quote from: stewart on November 05, 2008, 12:49:23 AM --- i should first get a handle on and wring all i can out of a setup then make changes 1 at a time
--- End quote ---
i hear ya there!
my buddies bike in its current 88*86 configuration is making similar numbers to yours, but on a dyno dynamics dyno, which we know to read lower than inertia dynos such as dynojet.
I am confident that he has more actual rwhp than your setup, however the power delivery (no KIPS anymore) and the hand made down pipe would not suit your riding requirements! (you do alot of hill climbing and the like yeah?)
it has made dozens of dyno runs, tried several hand made pipes, countless combustion chamber designs and custom ignition curves, not to mention variations in porting and carb/reed choice. the engine runs on methanol. it is also very reliable, being built for ultra long track speedway events.
so now we have come across a stroker crank and looking to make more power with it. the class the bike competes in has a 600cc limit, so we are looking to take full advantage of that. i think a 91*91 combo fits the bill nicely!
oh yeah, wiseco sent me the dimensions i was looking for, dont spose anyone has a port map for me eh?
thanks, mark
stewart:
i found more power and same tq with oxgenated fuel from vp than alky and i spent alot of time on that comparsion ,,dont know why the numbers would be off from 1 dyno to next or not but we have been very honest with our settings to get accurate comparsion ,,if you could please show us a dyno sheet so we can see what is up with the rpm and tq numbers as well,,i m always ready to learn,,,my experience with kips removal has been only a loss of bottom end power ,,..what carb do you use on that combo,,thanks for the info stewart
4stroker:
yeah mate i am not disputing your honesty or the accuracy of your dyno, just stating some findings we have made. one direct comparison example i can think of off the top of my head is a Hayuabusa street bike that a guy went drag racing with. it was modified to some extent and made 190+rwhp on a dyno jet. then it came into the local shop here with the dyno dynamics dyno, and after a tune up only made 160+rwhp, but it turned in consistently faster ET's on the strip than it had before.
the difference in power is not linear of course, the difference when at around 70-80hp is probably more like 7-10 hp between dyno's. this is due to the fact that the dyno jet is an inertia dyno, and the dyno dynamics is a retarder dyno.
when all is said and done everyone knows that all dynos are different and should only be used as tuning tools.
i believe the carb is a highly modified keihin 41 pwk. (taper bored power jet etc etc...)
not sure on the main jet and power jet sizes but i know it runs a 1.0mm pilot jet and a custom needle/needle jet.
i do not believe he has tried a lectron, or oxygenated fuel, maybe there is more power to be found in this 88*86 combo yet!
i will see what i can do about a dyno sheet.
stewart:
what is the average altitude there.. were at 1000 feet roughly..i like the 41 pwk carb they work great on gas and very ridable..but a 44 lectron will make more power is what i have seen thats why they use them on the pro stock nhra bikes
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