KX Riders
Maintenance & Technical => KX500 Original => Topic started by: sharpy on March 04, 2009, 08:13:30 AM
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Also when riding, pull in the clutch it revs some before smoothing out, again about 5-10 secs
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i would check for airleaks
if any air comes through unregulated it causes jumpin RPM.
maybe cracks in the rubbersection btween carb and reeds
maybe check with starterspray ,engine running,then apply some on the suspicious zones..
if there,s a leak ,the spray will cause the engine to rev up a bit ,just a bit ,
then you know what to replace
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Thanks for the response. I did that first thing and no change. This bike has come a long way in a short time. I just have this left and I'm smokin...
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I need mo info!
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Need mo better description! You have described clutch pulling in and throttle blipping both of which suggest different causes. For throttle blipping, what you are describing sounds like normal "surging". It is phenomina common to a K5 that is jetted correctly. What happens is that after you rev the engine it fires a few extra times and takes a few seconds before the idle returns to normal. This is normal and you just have to get used to it. The only way to get rid of it (that I know of) is to return to the over-rich stock jetting. If the engine revs up when you pull in the clutch then it sounds like your pilot jet is too lean, causing a small bit of lean run-a-way. You may notice that it is worse on cold days. The bike load keeps the engine speed normal and then pulling in the clutch releases the load holding the engine speed and it revs up. Hope this helps. Cam.
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Soooooooo my new riding style is ride it like I stole it and never use engine breaking. :-o It's a big change in my MO, I'm a firm believer in smooth is fast. 8-) A bit noisey with the little reving but I'm gone. Block pass anyone?? :evil:
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You might be able to get rid of a bit. What is your altitude and what pilot jet are you running. Cam.
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How did you check for air leaks :? Did you do an actual leak down test or did you look it over with the old eyeball. It could ba a bad main seal, that would not be that obviouse. :? Also like asked before what are your jet specs :?
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I only checked for leaks around the intake area with starting fluid. Sprayed it everywhere while running, no change. Ok, tuned some of the idle issues out with air screw and fuel screw. Road it around the block a few times 5 min or so. Now just as it starts to run out good, ( Full temp) The idle jumps up and stays at what might seem as 1/8 throttle or so. Should I try and readjust the air and fuel at this point or are there some other issues I might check out.( new piston, rings, good reeds and just cleaned the carb and air filter but did not oil treat the foam yet) Any thoughts would be appreciated.
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anyone?
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Startin with basics, not trying to be a goofball. You have a little slack in cable, before throttle pulls on cable? When you release from wide open, does it go whack back closed? With carb off, does the slide close completely? Leaks can be around the base gasket, intake, carb boot, main seal(inside ignition cover), could be gummy stuff in the carb, or jetting. Air leaks and low gas flow, hung slide, all are expensive, if you don't chase it down. Idle adjustment change it?
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I'm getting closer. All the advise is priceless. Keep em comming!!
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It's OK?
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Anyone know where I can get a good trunk monkey??
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Soooooooo my new riding style is ride it like I stole it and never use engine breaking. :-o It's a big change in my MO
What's engine braking? :? Oh wait, I think I almost went over the bars off a big double riding a friend's bike once because of that stuff... :-P
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Big double cheeseburger?? :roll: No engine breaking in the woods either?? Sorry, been riding road bikes for the last thirty years, have not owned a dirt bike since 1980. Tell me my best approach.
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my guess he (good) was jumping a doublejump..2 bumps in a row
and it prolly was on a 4popper where enginebraking is much more avaible then 2smokers.
bigbore2smokers however can be adjusted to have max profit of retarded energy
simply : no idle at all ,let it die @closed throttle,then when entering corners ,shift down 2 gear,
let the clutch go at ease and while reaching the corner,it drags too a nearby stall,
and without heavy braking you simply hit the track ,and take off again 8-)
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Yeah, sorry about that! :-D I was riding a KTM 620 and on a particular doublejump, the speed approaching the face of the jump and the angle of takeoff and distance to travel in the air required to just sort of sail off the lip. Being used to the two-stroke and being able to let off the throttle to sail because there's not much engine braking, the big four-stroke, however, has tremendous engine braking and pulled my front end down just off the lip. I didn't wreck, but my arms pumped up and I couldn't ride much the rest of the afternoon. :lol:
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Should I have a top end?? It seems to sign off right when I expect it to fly.
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You have ths stock pipe so it should have plenty of scary top end. I would suggest checking the powervalve linkage an verify that it is working. A conpression test will tesll you if you need a top end (or how easy is it ot kick over). Cam.
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the top end is new, and the kips was cleaned and set right on the marks.
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What is your jetting now?
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I have two, a little one and a big one. I imagine it's stock, mostly because it still has the stock piston with just it's first set of new rings. Stock pipe and so on. I was told the fly wheel was weighted for trail riding. (When I bought it) It has decent grunt but seems to fade on the pipe. Compression is at 160 psi. Roll on wheelies good in first three gears but again it's low end pull. As I get to the pipe where you expect that two stroke rush, it says grab another gear. :|It starts second kick and idles fine now, High reving problem resolved, and in the trails it's good. But when the trail opens up, funs over. Now keep in mind I've been riding modified gsxr 1000's, r1's and twins for the last ten years. Am I expecting too much?
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:lol:
No, it will rock. Not equal to gsxr 1000, per say, but definately 90mph on dirt feels similar to like 150 on the street. Its different, but that bike will pull hard. What gearing are you running? 14-49 should be good top-end with 14-47 having more and 14-45 having more than that. I run a 13-45 that is good for tight or open riding. A 14 with optional rear sprockets would be better for top-end acceleration. Or even a 15 for open smooth riding.
It runs strong to top of the gear then? Does it seem to have a powerband thats constant to the end or pulls hard then falls off on acceleration too soon? You want as constant of a pull as possible.
Retarding my timing added some r's. And there's alot of power in the main jet and needle settings. Stock is a good starting point, but too lean or too fat robs power. Main is easy to check by plug color after a wide open run.
IMO, that flywheel weight is only for tight trails mixed with tall gearing. To each his own, but adding weight to a bike anywhere is not for speed, maybe for control. They bring a pretty penny, though,and with the money, you could get some reeds or a pipe to get some easy power gains. Add power, you can pull taller and taller gearing, which equals less shifting and higher top speeds. You sound close to being there. You can change alot about how it runs, but always do one thing at a time, and if it doesn't work, don't be afraid to go back to original setting and try something else. Which is why its a good reason to keep notes.
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Is there a number on the jet to tell the size??
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Yeah. The main comes out of the big nut on the bottom. Remove that big nut(gas will come out) the brass nut in there is the top of the main jet. I think its like a 6mm. The jetting chart will work for you, since you are stock. Good to hear its running better.
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Holy crap!!! I just went for a rip down the road on pavement :-o :-o What a difference! Is it possible that when I was trail riding, and the big areas were gravel roads, was I spinning all the way?? The tank was smacking me in the face the hole way!! Lovin that!!
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I would actually expect you to be spinning more on pavement. Any chance your clutch is slipping or something like that. The bike should feel like a dirt version of the gixer except wheelie more. Something isn't right. Cam.
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Sounds like your motor is about there. Maybe you need a tire, or gearing change to get it right for ya' on the dirt.
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Naaa.. I know clutch slipping, not it. But appreciate the help.
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Any other advise?