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About pontoon

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  1. pontoon

    Needle Questions

    Haha good to hear. You realize it’s already adapted and running on my bike right? I’m just trying to find the perfect needle. I have a couple options that are passable but imperfect so far. Very good to know. Do you know what’s an acceptable cold start idle RPM? My old carb actually idled higher on cold start choke on. I assume the best way to find the ideal starter jet is to start the bike and turn the fuel screw? If clockwise increases idle speed, go to a smaller starter jet, and if counter clockwise increases idle speed, go to a larger starter jet?
  2. pontoon

    Needle Questions

    So I already have the FCR-MX 40mm. Others have got it working on the DR and report good results, even compared to the 39. Should I really be very concerned about this? I'm a little worried based on what you've written. In any case, even with imperfect jetting it seems to be running pretty well, although kind of low RPM on startup. Maybe I need a different starter jet. I have a 95 in there but it came with a 68. Others seem to run an 85 so maybe I should go for that. I was reading a lower starter jet will increase the startup RPM.
  3. Hey all, I’m trying to jet a 2008 FCR-MX 40mm off a CRF250R onto my 201) DR650. As I’m working on getting the needle tuned right, I’m noticing some questions... 1) Do the fuel screw and pilot jet always work hand-in-hand? Like, if a 40 pilot is a little too rich so I turn the fuel screw all the way clockwise, the idle might be perfect. But since the jet is richer than necessary, once I get on the needle at 1/8 throttle, is the fuel screw still helping compensate for that larger pilot jet? 2) Is it possible that needle changes can have a tiny effect on idle richness? I’m pretty sure my slide is fully closed. When I go from a Yamaha NFLR to Keihin EMP I see the idle becomes maybe slightly richer, although it could have been a fluke due to temperature variance between tests. 3) I think I’m seeing the EMP is too rich off idle, and the FMQ (will try EMQ but theoretically it’s the same needle root diameter anyway) is too lean off idle. Has anyone else noticed the needle root diameter causes too great a change in richness? Using an AFR meter I’m seeing a difference of 4-5 AFR e.g. “P” diameter 11 and “Q” diameter 16. I can’t use slide cutaway as a tuning parameter since Keihin doesn’t sell those for the FCR. Can I lean out the off idle by using a smaller main jet? Does the main jet effect 1/8 throttle at all? Currently my main jet is too rich anyway.
  4. pontoon

    Jetting D-Base for CRF250R

    I believe the pilot air jet is a fixed piece in the 2008 carb. Does anyone know by chance what size it is? 70? 100? Something else?
  5. pontoon

    Powering a Keihin TPS?

    I’m going to try a 12v to 5v step down buck converter. I’ve also been told a 7805 works well. If you want to regulate it perfectly a couple of capacitors are required as is shown in the Texas Instunents literature. I’ll try to report back with how it went if I ever finish this project. Got the o2 welded on and everything ordered.
  6. It looks like multiple companies make switches that look identical. Probably coming out of the same factory under different names. - Tusk - Baja Works - Sicass Racing - K&S Tusk is the cheapest so I’ll probably go with that. I actually might prefer plastic over a beefy alloy thing due to weight, on second thought. Thanks!
  7. Hey all! I’m switching the carburetor on my bike and am looking for a replacement for my existing headlamp/turn signal/horn switches. The reason I want to switch is my current one also has a choke adjuster which I won’t need. Also I’d really like something slim or perhaps out of the way so I can mount my clutch lever closer to the grip. Currently the clutch lever is a shorty lever which is just a little bit too far to the right to make it easiest to grab. Bonus points for high quality like HDB does, but even more bonus points for one switch unit that does it all in a slim package. Hi beam/low beam toggle, horn momentary , turn signal left/right/cancel.
  8. pontoon

    Powering a Keihin TPS?

    Will the TPS output in the range 0-5v if I input 12v or some other voltage greater than 5v?
  9. pontoon

    Powering a Keihin TPS?

    Ok, that’s very interesting. It’s fun to learn the advanced tuning side of things. As I’m looking into this, it seems like that device I mentioned above is totally unnecessary if I just get an Innovate LM-2. It can take any 5v analog input. If I were to feed the TPS 5v input, would it output in the range 0-5v? I understand I’d have to find a way to regulate this somehow. I found a 12v to 5v step down which might operate in the 4.8 to 5.2 range. That’s less than 10% variance and maybe I could live with that. I don’t plan to change the resistance of the TPS at all. I’m just figuring out how to get it the right input voltage. The LM-2 does serial out and SD card logging. Either way is fine. I don’t need real-time data. I just need very detailed data so I can study it later and tune based on the findings.
  10. pontoon

    Powering a Keihin TPS?

    I don't have an ECU. I was looking at this thing: https://www.ebay.com/itm/Module-Input-Single-Channel-10V-Voltage-RS-232-Output-Used/352189756939?hash=item520025360b:g:I4wAAOSwQS1Z6YjT:rk:41:pf:0 From the sounds of it, I should give up. Oh well, less work for me! 🎉 If I understand correctly, the issue is that my bike's battery (which I'd step down from 12v to 5v) would not supply a constant 5v, and so the throttle position would appear to change due to the TPS input voltage fluctuating, rather than the TPS position changing. Is this fluctuation significant? If not maybe I could live with a lack of perfect precision. Mainly I want to know with perhaps 5-10% accuracy where the throttle was. I'm using it to tune a carb.
  11. Hi all, I have a Keihin 40mm FCR MX off a 2008 CRF250R that I'm installing on a DR650. I want to wire power and ground to the TPS so I can wire the signal wire into a serial connector (to USB) and log this to my computer. I noticed TPS input is apparently 5v. My DR650 has 12v power. I understand I can use a resistor to make this happen, but is there an easier way? Can I send 12v to the TPS and will it just handle it? Is there a device I can buy that converts the power easily? Any additional tips on logging TPS and AFR and using this data in an easy to understand way would be awesome!!
  12. pontoon

    The KTM 200 Club

    Hey all, I’m building up my riding tool kit to be specific to the KTM. Is there any need for a 13mm or 14mm socket, 13mm or 14mm open ended wrench? edit: following is not true: It looks like the spark plug may need a 14mm open ended wrench.
  13. pontoon

    Rivet or clip type master link?

    Sorry to revive a thread but related to above, is it possible to start with a rivet master link and carry a clip? My small chain tool that I want to carry riding can't do rivet style master links.
  14. pontoon

    Replace pilot air jet 2008?

    Hey all I want to switch pilot air jets on a 2008 CRF250R carb. It looks like there are no flats for a screwdriver. Is this fixed in place? Is the engineer perhaps saying: you should never change this? I was able to split the carb in half and get access to the main air jet it seems.
  15. pontoon

    The KTM 200 Club

    Hey all, I noticed this gasket is torn and not fully sandwiched by the meta. Is it worth pulling this apart and putting a new gasket in? Edit: probably helps if I attach the pic