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Anything and everything RMX. Share videos, photos, tuning, mods, parts, and part suppliers for your RMX250’s

  1. What's new in this club
  2. OK - forget about the above. We were just being stupid, the tacho is reading fine! So used to 4T idle we just presumed the idle showing for the RMX was double what it should be, but I guess 2T or at least this bike idles higher than your same era or newer 4T. I took the bike out for a spin and it topped out just below 9k rpm in any of the gears. This tacho would also work in most 4T singles, as they run a wasted spark ignition. So, overall I learned more about ignition systems than I knew before even though I started down the wrong path for a solution I didn't need. I'd say that is still worthwhile 🙂
  3. I will do! Looks like I either need to convert the sine wave signal to square wave, divide, then convert back again. Using a monostable multivibrator, flip-flop, PLL circuit - or a mix of all 3. It's way above my head, but I'll keep researching 🥴
  4. Little to deep for me 😂old school is cool keep us posted love to hear how it works out
  5. Hi Folks, Been a while since I posted - too many non-bike related lockdown projects here in Scotland but here I am back to a small job on my Dads RMX. He sourced an analogue tacho which is reading twice the actual engine revs, as the tacho is designed for a 4 stroke engine. He's asked me if there is a way to divide the ignition pulse/frequency to the coil so he can use this tacho? I did some research and went about making a little microelectronic circuit with a CD4017 divider chip - needless to say my microelectronic knowledge is pretty terrible, and this didn't work. The chip simply blew when I connected the pulse/clock feed to the circuit. Here's roughly what I followed - with the CDI pulse going into the clock input of the 4017 chip and the output going to the tacho. https://circuitdigest.com/electronic-circuits/frequency-divider-circuit-diagram I suspect the chip didn't like the pulse being AC? Or maybe the pulse was too high in current or voltage. The CD4017 chip is rated between 3-18v. Any pointers in how I may solve this with some electronics? We could buy a 2 stroke ready tacho, but ones on the market appear to be digital readout only - and my Dad is too old school for that. Thanks, Gordy
  6. The Power Dynamo DC unit was fairly inexpensive. Has been reliable, easy to start, and runs well. What I dislike about it, is it's unkeyed flywheel that makes timing it a hit-or-miss affair. You can go back, and forth with it all day, until you learn to hold your mouth right while tightening it down. Although it runs well, I think it could be better. My KTM 200 will suck it's headlight out!
  7. Hello Fellow RMX'ers! Quick intro. Been riding motorcycles my whole life, 58 now and living in Mukilteo, WA. I just got back to the US after 14 years in Brazil. RMX's are still very popular there and I've had one on my radar for a while. I thought I would get a Yamaha WR250 but this bike came along instead and I jumped on it. It's a 1995 model with low hours, had the original tires, but still needed some work. I paid $1400. The biggest challenge right now is the carb. Came with a china copy of PWK 38. I couldn't get it right so I picked up a used genuine 36 PWK that I'm starting to jet. 178MJ, 48 pilot, R1469 needle on middle clip. I don't have a place to rev it out in my neighborhood so going to the track tomorrow. Bike is stock with an FMF gnarly exhaust. Top end looks like a virgin. It's got great compression and sounds really tight. Shifts great and butter smooth clutch too. I rode it once around the block. Pulls nice down low but signs off very quick after mid range. I have to remember it's not an MX'er and probably has the thick head gasket. I'm sure there's more pony's to be had. I have the thinner RMX gasket. Jeremy encouraged me to check PV's so probably will pull the whole top end soon. I've gotta ride this thing tomorrow first. I put new tires, chain and sprocket so far. I had to replace the rear spokes also and learned how to lace and true a wheel for the first time. I'll let you guys know how my first MX practice day goes. Going to the whidbey track by the navy base for you washington people. Anybody else using a 36 PWK? I exchanged messages with another guy (David) in Idaho running the 36mm PWK with MJ 190 PJ50 dcj needle c5. Main jet sounds kinda big but it's working for him. Maybe he's in this club. Selling his bike and it sure looks nice. Well that's my story. I've started pouring through the topics. Lots of info here. Thanks guys.
  8. Sorry to hear that. I’m guessing it’s the flywheel, or rotor magnets, that have ‘crumbled’ into pieces? Did one of the stator screws back out to cause this? Powerdynamo makes a aftermarket ignition system for the RMX, but I don’t think it would be a whole lot cheaper than going back with OEM. IIRC @ventabular is running the Powerdynamo ignition, so perhaps he can chime in on the details. I did away with all the stock CDI components a few years ago for programmable Zeeltronic DC-CDI‘s. One of the best mods I’ve done to my RMX’s. 👍 Since I didn’t need it anymore, I re-wrapped one of my old magneto cores in 20ga. for some additional 12v power so I can run a cooling fan, when I get around to installing....
  9. So my 1990 RMX Magneto crumbled into pieces.. enough so that the motor would not turn over.. If anyone would be able to guide me in a replacement other than OEM or advise on a better way that would be awesome..?? Thanks Tim
  10. Lol. Yeah, I went back and edited the EGT references out. Was probably confusing how I wrote that. But, yes, EGTs are a important part of 2 stroke tuning. Low EGTs at lower RPMs help slow the reflecting wave inside the pipe, (which give us the supercharging effect). At high RPM, doing things like leaning out A/F ratio and backing off ignition timing raise EGTs and help speed up the reflecting wave. OEMs (to the best of my knowledge) only use the power jet to lean out high RPMs. Trail Tech has a good lineup of tachs/speedos. I’ve ran both the Vapor and Voyager. The Vapor, unlike the more expensive Voyager, records max RPM. I miss that feature with the Voyager.... A simple cheap hour meter records max RPM. I think that was a really dumb move on Trail Tech’s part getting rid of that feature on a more expensive unit...
  11. You sound like turbo car tuners with that EGT stuff! Btw, I looking for a simple tach for single cyl. 2-stroke.
  12. Keep in mind this is on my RMX’s. The ‘C’ length is going to be leaner in the same clip position than the OEM Yamaha D&E length needles. The J starting diameter is also leaner than the W that the YZ comes with. I gave the #40 power jet a try in my RMX and didn’t like it. I believe the YZ doesn’t deactivate the PJ till 50% throttle. Many seem to experience a lean spot around 1/3 throttle, so raising needle and going smaller with the PJ is supposed to help that ??? With my Zeeltronic I can change TPS% and RPM of PJ opening/closing. The combo of raising needle and #40 PJ definitely did not help low RPM/TPS, so I lost the clean low RPM fueling I had, plus the low 4500RPM power band hit. Above 4500RPM and 35% throttle is where I have my PJ set to enrich A/F ratio. Thinking back, not even sure why I tried it. Lol.
  13. I will try the N3Cj. Tried the #40 power jet in my 295 with inconclusive results. That bike was hard to jet. The new stocker is apiece of cake. May try it with the new one, but frankly, I can't tell that it needs anything until maybe the temperature drops.
  14. It has been a while since I got to work on my RMX, the shop is very busy, doing more work than last year even with corvid 19 rising up in Texas, the cam for 2 strokes that came with the grips, and the cam for RMX is 2 different sizes, RMX is smaller, the new 1 is just barely large enough that it will keep the throttle at wide open works normal till wide open then hangs. I filled the cam down a little and same, I didn't want to ruin it so I stopped, even after I filed it, it was still larger. So now we know if we want to use the Odi grips the housing will have to be changed to a large style or newer style. I am going to take the housing off my 02 RM250 and try it 1 day.
  15. Well boys, I have some sad/great news. Sadly I'll be selling my RMX soon, but the great news is I just picked up a brand new leftover 2019 KX 450 from my local dealership. I got an incredible deal on the bike because of the covid pandemic madness. It was way too cheap to pass up. Very rarely are new high end dirt bikes on sale for $2,500 off, even as a leftover. I'd love to keep my RMX so I can have a 2 smoker woods weapon and have my KX for my local tracks. However, it's just not economical and I feel I wouldn't be getting my $'s worth out of the KX. I've already started prepping the KX to make it be a great mix between woods and track use. I'll have the RMX up for sale soon. If anyone is interested, I can send a huge list of specs. It was basically completely restored last year aside from painting the frame and engine. 22.5 hours/260 miles on rebuild Just figured I'd share the news! Pic below!
  16. No no. That is correct. On the North American RMX models the exhaust outlet changed from 54 to 50mm in 1993. RMX’s here never got a low slung pipe like you have. I believe 1996 was the first year the RM got a low slung pipe, here anyway.. I just assumed someone has installed a newer cylinder on your bike. It’s had quite a bit of custom work done to it. But, yes. Good idea to see what was done to install the low slung pipe. They might have changed the cylinder, or cut and welded the larger inlet on your pipe. I’ve been forced to use the ‘App’ here lately because of a error that I’m using a ‘add blocker’ on my phone, so I can’t zoom in on your picts and see what was done with the rear pipe mount. You may have to do some cutting/welding there too? Doesn’t look like much clearance with the custom shock. The different picts your finding for 96’s are most likely JDM and North American. We never got the low pipes or updated plastics... ☹️
  17. Hmm.. What About the exhaust outlet diameter? Since my bike is a 1990 (registered 12/1990 so might be 1991 year model Too..) and ive heard that In later models of rmx, suzuki changed the diameter of the outlet? Am i wrong? Basically i wouldnt want to order a pipe for 300 euros if it doesnt fit 😂 When i tried To Google a 1996 Rmx, i found pictures of slightly different looking rmx's. Some had the pipe like i do and Some had the pipe that exits higher and outside of the frame? 🤔 So maybe They have a rm pipe too or..?
  18. Oh, wow. Someone did some serious ‘customization’ to your frame. This topic came up recently in the Suzuki 2 stroke forum. Paranoia was looking for a aftermarket pipe for his 98 JDM RMX. I referred him to this ADV rider topic. https://advrider.com/f/threads/aussie-rmx250-adv-riders-sign-in-here-please.710468/page-6#post-19250521 About half way down page 6. It sure looks like the 96-98 RM pipe will fit, but not so sure about any of your rear mounts for pipe/silencer...
  19. What pipes are you guys running with your rmx's? And also i have a question About My pipe. Do you guys know if there are other suzukis, that might have the similar exhaust pipe compared To rmx. Some previous owner fitted newer plastics To my rmx and Some other pipe. Now Im thinking of getting a new exhaust because the current one is so worn and dented, but dont know that what bike has the correct pipe that would fit mine 🤔 Originally the last part of exhaust on rmx goes back in front of the frame, but in my bike it goes behind the frame. Sry for my bad english but maybe u know what i mean 😂
  20. I have a - 90 rmx with newer Rm125/250 plastics and gas tank. Dont know what modifications must be done To fit them, cause Some of the previous owners installed them. But i like the way it looks 🙂
  21. Lol Yes, my bikes are nothing like stock anymore. These engines definitely have potential. 👍 It was probably more the squish band, than the actual compression. Squish and timing need to work together, not fight each other. If you spend lots of time under 1/4 throttle as I do occasionally on single track, the needles starting diameter is important. The PJ carbs that came on the RMX are way too rich in that area, and even the brand new PWK I bought years ago was too rich at 1/8th throttle for my liking. Leaned that out two sizes. J to a L diameter. I do still mod heads, but typically in the winter when it’s too cold and crummy outside here in the PNWet. Been having a hard time getting guys to return cores to keep the head thing going... Edit; Congrats!! The YZ is a good platform (haven’t changed for almost 20 years) and excellent parts availability. Read up on the #40 power jet mod in the Yami section. Lots of guys seem to like it. One of my favorite needles (one I’m running in my 96) is the Yamaha N3CJ. I like it better than the Suzuki NECJ in my 98. Throttle is a bit more linear from 1/2 to WOT 👍
  22. Now we're talking. There's no way mine would do that at 1700. I,m thinking about going back to the stock head gasket until I can update the ignition. Do you still do heads? Edit: BTW, I bought that YZ 250 today, and spent the afternoon fixing bizaar jetting, and suspension clickers. It now runs like Hammy the Squirrel (Over the Hedge) loaded on caffeine. The RMX still steers a tad better.
  23. Ahh. Gotcha. No, never had a problem with my engine stalling, but with the stock CDI, I could never set the idle speed really where I wanted it. 1450 felt way too low, if I’d try to open the slide more, it would get hung up at 3100. Mostly due to the timing curve going from 0 degrees advance at 1500 to ‘all in’ 16 degrees at 3000, and partly due to using a higher compression head with a functional squish band. With the Zeel I’m running 22* (0%TPS) at my target idle speed of 1700, and I’m actually advancing to 24* at 1500 (helps a bit when engine is cold). I’m also using a ‘00 RM 250 exhaust valve solenoid to keep the primary exhaust valves in the closed position up to 4000RPM. Those two things made a huge difference in low end grunt. I can be at 1700, crack the throttle a bit, and (traction permiting) instantly loft the front wheel. Makes log hops clutch-less right from idle. 👍
  24. By "Bang to the bottom" I mean an engines willingness to not flame out at very low revs,- if you keep the throttle cracked open a wee bit. The KTM 200 with a 12 oz. flywheel weight will do this like people describe their 300's My RMX, not so much. I practice at home by turning very tight circles at less than walking speed. I use 1 finger on the clutch in as analog a way (variable) as I can. This is both balance, and finger training! The RMX clutch ,I find to be very progressive. I am too damn old to go fast!
  25. Yes, I definitely agree with that! Fresh basket, hub, and my favorite clutch kit, the EBC dirt racer, make for one of the best clutches I’ve ever had on a dirt bike. 👍 I tried to talk ya into a Zeeltronic. IMO the PDCIS-MX11T we developed is best aftermarket CDI out there. Been meaning to create a Zeeltronic topic here in the club, but it will be a long-winded one, and just haven’t had time lately. My topic on the Zeel in the Suzuki forum is a complete mess. Really don’t want to link that catastrophe of a topic here.. Ha ha Bang to the bottom? Don’t know what you mean by that, but as far as starting, yes, the Zeel starts extremely easy. Programming a smoker timing curve is not as scary as one would think, and although not ‘plug and play’ the wiring can be done by connecting as few as 6 wires... Mine’s a bit more complex. Never ridden a KTM 200, but comparing my RMX (after Head and CDI upgrades) to my old 96, ‘00, or ‘06 RM’s, RMX all the way!!! I’m really liking my DRZ400 forks. Haven’t even re-valved them. Swapped the .44 springs for .40’s and felt the need to re-valve the rear shock afterwards. DRZ forks also open up the opportunity for oversized front brake rotors. I felt the Gnarly as a downgrade, but not everyone likes or wants the same type of power. It does have better low and mid power over the stocker, but compromised all the top end power. And yes, Gnarly generally needs leaner jetting... The Pro-Circuit for RMX is a good mid-range boosting pipe. My favorite, the FMF Gold Series, was discontinued almost 20 years ago... Yup, we’re WAY off topic now. Lol.

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