jse Posted July 20, 2012 Report Share Posted July 20, 2012 Some people just lay the bike over to flood the bike when it is cold, since the carbs dont seem to get overly rich enough to start these things when cold. The Dellorto's usually come with a #60 or #70 starter jet. I find that changing the SJ to a #80 (or drilling the SJ out to .031" like I did) made my Pro usually start 2nd kick, in any weather, frying to freezing. Jon Quote Link to comment Share on other sites More sharing options...
sting32 Posted July 20, 2012 Report Share Posted July 20, 2012 His should be a Kehin like mine and dads though, so that is why I didnt tell him to drill out things, lol, I remeber you or Steve telling me we ought to do this years ago like on the 04's. Started "pre charging" rock exercise, and it works good enough. you get a feel for what it takes, dad does more, I do less for our respective bikes. I do it, if for nothing else, to save any wear or tear on the starter parts... know what i mean? I mean, 2 seconds and you save 4 or 5 kicks? = No Brainer. Quote Link to comment Share on other sites More sharing options...
razorback Posted July 20, 2012 Author Report Share Posted July 20, 2012 Yep, it's a Keihin, Model PWK 28 I think. Gonna pull it off tomorrow, give it a cleaning and play with the needle clip position and see what jets it has in it. The local KTM parts guy says the KTM 300s use the PWK 28 and he has just recently got an assortment of jets in if I need any. Does anyone know what the "recommended" jets are at 0-1000 ft.? I know the recommendation is just a staring point but I'd be curious if they are in fact what would normally be recommended for this elevation. Quote Link to comment Share on other sites More sharing options...
aussiechris Posted July 20, 2012 Report Share Posted July 20, 2012 Hi Razorback, The standard settings for the PWK28 on your Raga should be: Main Jet: 122 Idle Jet: 45 Needle: JJH with clip in the middle groove Slide: 3.5 cutaway Idle Mixture Screw: 1.5 turns out Float height: 19mm from bottom of float to gasket surface (with carb inverted). I have moved my needle clip to one position richer to smooth out the sharpness that I had when rolling off the throttle. It runs absolutely perfect now. However, I find the bike likes plenty of throttle when starting (unlike the older models with the Dell Orto carbs). Probably about half throttle hot or cold. For cold starts, I pull the choke on and give it a quick kick. It will usually start first kick if I remember to give it throttle. No more than two kicks from cold. It will fast idle perfectly with the choke on and I do that for five or ten seconds then flick the choke off. It runs fine straight away whereas the older bikes would take a fair while to warm up before they ran any good. By the way, I'm at about sea level - but our winters are no where as cold as yours. Chris. Quote Link to comment Share on other sites More sharing options...
jse Posted July 20, 2012 Report Share Posted July 20, 2012 His should be a Kehin like mine and dads though, so that is why I didnt tell him to drill out things, lol, I remeber you or Steve telling me we ought to do this years ago like on the 04's. Started "pre charging" rock exercise, and it works good enough. you get a feel for what it takes, dad does more, I do less for our respective bikes. I do it, if for nothing else, to save any wear or tear on the starter parts... know what i mean? I mean, 2 seconds and you save 4 or 5 kicks? = No Brainer. Doh! You're right....brain fade, forgot it was a Raga. I would be surprized if the KTM 300 runs the PWK 28, it's more likely a PWK 39. He may have to order some jets for you as the 28 takes much smaller jets than the 39, which usually runs a main in the area of #175. I have some jets possibly and will check my jetting kit and let you know. Take a jet inventory (or "map" as it's called) when you clean and check the carb so we have a start. Main, pilot, needle, needle jet etc. The float arms will be parallel to the sealing surface of the cab body to be at the correct float level, with the carb held so the float arm assembly just touches the float valve pin. The enrichening circuit usually works well without modification in the Keihin, just don't open the throttle when kicking at first. Jon Quote Link to comment Share on other sites More sharing options...
aussiechris Posted July 20, 2012 Report Share Posted July 20, 2012 Hi Jon, I probably got my post in while you were typing yours. Just to clarify, I bought my Raga 300 brand new and the settings I listed were how it was supplied. Like I said, this is the best carburated (if that's a word) bike I've ever had. But I disagree on giving it throttle while kicking though. It took me a while to figure it out as I used to start my 2001 TXT321 with little or no throttle. In any case, it costs nothing to try both techniques. Having said that, I have nothing but respect for your opinions. I've followed all your Gas Gas Guru technical articles for the past 10 years or more and you've helped me heaps. This is my chance to say thank you for all your hard work. Regards and thanks, Chris. Quote Link to comment Share on other sites More sharing options...
jse Posted July 21, 2012 Report Share Posted July 21, 2012 Hi Jon, I probably got my post in while you were typing yours. Just to clarify, I bought my Raga 300 brand new and the settings I listed were how it was supplied. Like I said, this is the best carburated (if that's a word) bike I've ever had. But I disagree on giving it throttle while kicking though. It took me a while to figure it out as I used to start my 2001 TXT321 with little or no throttle. In any case, it costs nothing to try both techniques. Having said that, I have nothing but respect for your opinions. I've followed all your Gas Gas Guru technical articles for the past 10 years or more and you've helped me heaps. This is my chance to say thank you for all your hard work. Regards and thanks, Chris. Thanks, Chris! I have a lot of fun writing those articles and besides, at my age I have to pass on all the stuff I've learned before I croak.... My advice as to closed throttle is just based on the design of the enrichening circuit. I also agree with you that an open throttle may also work and the best way is to try both techniques to see what works best. The PWK is a different animal from the Dellorto and the concave design of the slide would make the open throttle technique work with the PWK but probably not be as successful with the round slide Dellorto when I think about it. Cheers! Jon Quote Link to comment Share on other sites More sharing options...
razorback Posted July 21, 2012 Author Report Share Posted July 21, 2012 (edited) You guys are both awesome! I really appreciate the help. It looks like it's all stock: - Main Jet: 122 - Idle Jet: 45 - Needle Jet: No marking on it that I can find - Needle: JJH with clip in the middle groove - Slide: 3.5 stamped on the bottom - Idle Mixture Screw: ~1.2 turns out - Float height: Looks good Since I've got it, I am going to install the low compression head and see how I like it. Would jetting need to change or just require a mixture adjustment? Here is a shot of the cylinder. Does this look normal or does it look like it's been hot? Man, I still marvel at how simple yet how precise this bike is. Loved removing the rear fender and air box by removing 4 screws and loosening a clamp... and hello, there is the carb sitting out in a big, uncluttered space that is easy to get to and remove. And here is my helper this evening: Edited July 21, 2012 by razorback Quote Link to comment Share on other sites More sharing options...
razorback Posted July 21, 2012 Author Report Share Posted July 21, 2012 The pwk28 is typical of other Keihin carbs I've worked on and was very easy to strip, clean and put back together. Here is all the bits clean and ready to reassemble: New low compression insert with new o-rings, bolts brushed clean with a little anti-seize on them. I used Sil-glide on all 3 o-rings and on the copper washers and it's ready to bolt on in pic below. It went on easy and I was able to borrow and smaller 1/4" torque wrench that worked on all 6 bolts! And wouldn't you know it, I pulled the reed block to inspect it and the gasket tore... DANG! Now I have to wait until I get another one. Any good alternatives? I'm sure I could make one if I could find appropriate material. So I'm stuck until I can get or make another gasket. Any ideas? I'll drop by the auto store tomorrow and see what they have in the way of gasket material. How critical is the thickness? Quote Link to comment Share on other sites More sharing options...
jse Posted July 22, 2012 Report Share Posted July 22, 2012 (edited) The pwk28 is typical of other Keihin carbs I've worked on and was very easy to strip, clean and put back together. Here is all the bits clean and ready to reassemble: New low compression insert with new o-rings, bolts brushed clean with a little anti-seize on them. I used Sil-glide on all 3 o-rings and on the copper washers and it's ready to bolt on in pic below. It went on easy and I was able to borrow and smaller 1/4" torque wrench that worked on all 6 bolts! And wouldn't you know it, I pulled the reed block to inspect it and the gasket tore... DANG! Now I have to wait until I get another one. Any good alternatives? I'm sure I could make one if I could find appropriate material. So I'm stuck until I can get or make another gasket. Any ideas? I'll drop by the auto store tomorrow and see what they have in the way of gasket material. How critical is the thickness? Most auto supply stores have sheets of gasket material that work fine. I buy sheets of various materials to have for emergencies and keep them in my trailer. The gaskets sheets are usually near the sealers, epoxy etc. area. Judging by the large radius at the squish band/chamber area, the insert should smooth out the throttle response well. If you can't find any material for the reedcage gasket, let me know and I'll send you one. Jon Forgot to mention, use the thickest material they have. Edited July 22, 2012 by jse Quote Link to comment Share on other sites More sharing options...
razorback Posted July 22, 2012 Author Report Share Posted July 22, 2012 Sure enough, I found some Felpro rubber/fiber gasket material that is almost identical to the original and made a reed block gasket. Put it all back together with a new plug, a freshly cleaned air filter and it started 2nd kick. It's running great at 1.5 turns out. I rode it about 10 minutes to warm it up then changed the oil. Rode another 10-15 minutes and hit some long steep hills (for Arkansas ridge county that is) and it feels great. It does feel a little softer but not as much as I was expecting and it shifts smooth again. This is the first time however, that I have been able to start it while in gear. Normally, there is too much clutch drag but now that the carb is clean and the oil changed for the 2nd time, I can finally park it in gear and not have to mess with finding neutral to start it back up and ride again. This is a BIG improvement since neutral is still elusive to me. Also, I forgot to mention that the inner o-ring was bad. Also, thinking back, my overflow tank tests were flawed and can be ignored. Now the overflow tank only has a splash in it after a fill up and nothing more squirts out plus when I take the cap off, I CAN see fluid in the radiator. The fan cycles on/off at idle so it looks like all is well. I have no idea when the o-ring failed but I'm guessing that it must have caused the hard starting as there would be water in the combustion chamber. It's starting 1st kick when warm and running strong so I think I'll keep it! Thanks again for everyone's help and looking forward the the night trial next weekend and meeting some other trialers. Quote Link to comment Share on other sites More sharing options...
aussiechris Posted July 22, 2012 Report Share Posted July 22, 2012 Hi Razorback, I'm glad you've got it all back together and running well. Don't be too concerned about it being difficult to find neutral while the engine is running. Mine was like that too. The clutch was draggy and not progressive from the start but it's great now. I've had my Raga for 10 months now and the clutch has just started to come good. I was trying it a lot on the weekend and I can now find neutral easily (with the clutch lever pulled in to the grip, not one fingering it). It's also really progressive now. In the meantime, you can try jiggling the bike back a forth while moving the gearshift and also giving the throttle a rev and shifting neutral as the revs drop down. I hadn't started my bike since a trial two weeks ago. On Saturday, it started 1st kick (choke and plenty of throttle). We made some massive new hill climb sections. My 300 Raga just ate them up in 4th gear including the lines with no run-up. And that's with the tallest gearing (11 front, 41 rear). I reckon these bikes take 6 to 12 months to come good, so stick with it and you will be rewarded. All the best, Chris. Quote Link to comment Share on other sites More sharing options...
razorback Posted July 22, 2012 Author Report Share Posted July 22, 2012 Hey Chris, it does seem like the shifting takes some technique. I was in 2nd, and slowing to a stop at one point today and was able to find neutral before I stopped. It just slipped right in. Haven't been able to do it since but I see it's possible now. What do you mean by "progressive"? My stop routine was starting to look weird. I'd pull the clutch, stop in 1st gear then lean over and find neutral with my right hand after missing it a couple of times. Then I would lean over to the right to push the kick stand down... with my hand as well. Can't seem to get the heal of my boot to catch the stand enough to push it down. Now when I stop, I just have to manually push down the stand with my hand. Now that's progress! Thanks for the help. Since mine is a year old and ridden by a Sr. expert class rider, it should be coming into it's own about now Quote Link to comment Share on other sites More sharing options...
aussiechris Posted July 23, 2012 Report Share Posted July 23, 2012 Yes, I think we all have to reach over and put the side stand down by hand. When I said the clutch was progressive, I meant that it engages nice and gradual rather than coming on all of a sudden like it did when new. You should be able to find neutral using your foot. Have fun at the trial, don't try too hard, just relax and enjoy riding on a new property. I also have a trial this weekend. Chris. Quote Link to comment Share on other sites More sharing options...
razorback Posted July 23, 2012 Author Report Share Posted July 23, 2012 Gotcha! My clutch is definitely progressive then. Now that I have replaced the damaged oring and know what a working cooling system behaves like, it's time to ride. Thanks again. Quote Link to comment Share on other sites More sharing options...
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