The Yamaha TW200 Thread...

Discussion in 'Thumpers' started by neepuk, Jan 10, 2009.

  1. RCEMT-P

    RCEMT-P Been here awhile

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    Alright carb guys. I tore into my carb today to install the procycle kit. So I put the 34 pilot in, and a 130 main. Bike was stock. Came with a 126 main. The procycle kit comes with a needle so I installed it also. I put one shim between the clip and the white plastic bumper. Set the air screw to 2.25 turns out. So it fired right up. I already had it out and about earlier in the day. Choke all the way in right away. So I took it out. I noticed increased response, seems to rev up faster. Pulls alittle harder. So I figured all was well but but then I found a problem. Runs great if your either accelerating or coasting but the 1/8 throttle maybe heavy 1/8 turn just cruising through town it hesitates. Almost no power, takes a second for it to pull out that small spot. Then runs like a raped ape. What's the advise. We have 5 days of raining coming wouldnt ya know.
  2. Padilen

    Padilen Long timer

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    My parents were the same, street legal & plated. TS90 was mine.
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  3. pazzo

    pazzo Been here awhile

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    :D That XR75 was my first bike. Great pic.
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  4. Randy

    Randy Long timer

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    Sounds like it may be a bit fat on the idle to needle transition. Then again it could be a lean stumble...

    If I remember correctly, the screw is actually a fuel screw rather than an air screw on the TW carb. They have exactly the same effect, but opposite... Turning an air screw OUT leans the mixture. Turning a fuel screw OUT enriches the mixture.

    Easiest is to start with the air/fuel screw... Get the bike up to operating temperature. Slowly turn the air/fuel screw in until the engine starts to die, keeping track of how much you move it from where it is now. Go back to starting position of 2.25 turns out. Now do the same turning it out until it starts to die, keeping track of how much you moved it again. Now, put it exactly between those two points. Adjust idle if necessary. Alternately, you can adjust it for highest idle, then set idle speed. But, I prefer the first method.

    A good rule of thumb is 2.5 turns out from lightly seated. More than 1 turn in or 1 turn out from that starting point indicates you need to either go up or down one pilot jet size, depending on if the screw is an air or fuel screw, and which way you need to over or under turn it out. Hope that makes sense...

    Try it again and see if there's any improvement.

    If not, leave the air/fuel screw alone once you've done the above, and try removing the shim from under the needle. Be sure to inspect the diaphragm while the top is off as any small tear, crack, etc, will also affect the way the slide responds to throttle inputs.

    I forget off the top of my head exactly what my setup is, but I know I posted it before in this thread back in October or so. But, I also installed a DG exhaust at the same time so my setup may not exactly be right for your otherwise stock bike. Then again, I have no idea how much, if any, the DG exhaust matters as I did it all at the same time and got lucky with my initial setup.


    ETA: I found where I posted my setup:

    "I recently installed the DG exhaust as well. I also installed a new UNI airfilter and a Procycle jet kit using the supplied 34 pilot, supplied needle with two shim washers, and a 130 main. Oddly enough, when I pulled the anti-tamper plug from the fuel screw, I found it already set at 2.5 turns out. Each bike is different of course, but if you're using the Procycle Jet kit, I found this setup to work really well and haven't felt the need to play with it further."
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  5. WECSOG

    WECSOG Dirt Road Denizen

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    The XL70 is one of my favorite bikes! In fact I have a jalopy bike that I built on an XL70 frame. It is street legal and plated. My tagline is from an ADV inmate's reaction to seeing that bike.
    Gravelmap sounds very interesting. I'll check that out.
  6. Randy

    Randy Long timer

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    You know what they say... "Photos or... " :D
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  7. WECSOG

    WECSOG Dirt Road Denizen

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    You asked for it! :jack
    Fortunately it doesn't look quite this bad any more...
    xl70_125.jpg
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  8. engineman

    engineman Been here awhile Supporter

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    So I've been commuting on my TW the last couple of weeks. Its 33 miles of gravel and 2 lane highway each way, 55-60 mph. Issue is I'm only getting about 40 MPG, hitting reserve at around 56-60 miles. Seems a little low to me. I'm not exactly a small guy, 6'2" 270# geared up. Bike seems to run fine but thought I'd get a better. My KTM 690 gets 45 mpg on the same route
  9. Randy

    Randy Long timer

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    Made a little trip on the TW today. I took a partial gravel route over to Franklin, GA, then to Roanoke, AL where I picked up the SEAT. Then, I rode the SEAT from Roanoke to just above I-20 in Heflin, AL. Most of the trip between Roanoke and Heflin is gravel/dirt. By then, it was getting late, and I was pretty tired so unfortunately I had to bail and head for home on two lane back roads. Total elapsed time on the bike was just over 8 hours, with 230 miles covered. May not sound like much but I'm BEAT!

    A few photos from the day...

    WTF?

    IMG_0341.JPG
    IMG_0342.JPG


    While you can't see it for the mule, the guy in the yellow shirt was grilling on the back "porch" of the wagon. I guess that's the landlocked Alabamian version of a "party barge". :dunno


    And I have a small rant about the state of our National "Forests". With all of the development of private land in this country, you may think that National Forest should be... what? Ummm, maybe actual forests? As in, protected natural areas of NATURE for us all to enjoy. But, no... I've been in two just recently and saw pretty much the same thing... Our National "Forests" are pretty much just tree farms these day. An actual FOREST in the southeastern US should be a predominately deciduous forest with mature examples of the native hard wood trees. And yet much of what I rode through in the Talladega National "Forest" today was almost exclusively pine, and much of that was sparse, with huge tracts having piles of logging leftovers. It was not attractive, nor did it give me the sense of nature that one would find in a pristine protected wild area. Really pretty sad state of affairs if you ask me... Oh, and I even passed two loaded logging truck trailers... And what do you imagine they were hauling out of the "forest"? The very hardwood trees that we should be saving so that we actually have a true forest rather than a pine tree farm.

    IMG_0343.JPG

    :Ruskie

    Rant off.

    And a few other more friendly shots from the trip...


    IMG_0344.JPG
    IMG_0345.JPG
    IMG_0347.JPG

    All in all, a very good day! :yum

    My next task is to attempt to make a semi loop that combines this section of the SEAT, from Roanoke north to Cheaha mountain then south along that portion of the Alabama Skyway, and back home. That section of the SEAT brings you to a portion of the Alabama Skyway south, so it's just a matter of finding an interesting route back home from there. Just making it to Heflin and back home was a very full 8+ hour trip, so going further north on the SEAT would really need more than one day.

    Ultimately, I'd like to do a multi day trip starting in Roanoke, following the SEAT up to N GA, do the Blue Ridge Gravel Century, then the Smoky Mountain 500 and back. But that'll take some time, planning, and commitment on my part...

    :ricky
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  10. Yamasakialo

    Yamasakialo Adventurer Supporter

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    So what type and size tire? I have a 241 to go on but this one sounds intriguing.
  11. Cyclepath

    Cyclepath Lost wanderer

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    Many years ago.... and I mean many :-) I did a restoration on a Honda xl70 and gave it to my daughter. She was 10 at the time. She had a lot of fun on that bike.
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  12. Cyclepath

    Cyclepath Lost wanderer

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    Not sure what others are getting but mine got around 50mpg on a mix of gravel and pavement. Sometimes a little less and sometimes a little more. I just installed a diaphram carb from china and have not tested it for mileage yet but it runs way better then it did with the older carb. 1994 TW200.
    I have a Kawasaki w650 twin cyl. that gets 63 mpg. Go figure that one out..... :-)
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  13. Randy

    Randy Long timer

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    I don't usually keep up with mileage. Kinda weird too since back in the day before fuel gauges, I always knew as the odo was my "fuel gauge". Then along came bike fuel gauges and I guess I got lazy to a degree. And with the opaque Clarke tank, I can see my fuel level at all times so it's not of much concern. I keep meaning to get some numbers so I can estimate my tank range a bit better. Just haven't gotten around to it yet.

    On my little trip yesterday, most of the ride to Roanoke, and along the SEAT to Heflin was off-road where obviously my average speeds were lower. I did decide to stop to top off my tank in Lineville. I remember looking at how much gas it took, and the odo, but was too lazy to pull out my phone to calculate the mileage. I think I remember 1.223 gallons and 93 miles, which would be 76 mpg. But 115 miles also comes to mind... :dunno Once I got up to hwy 281 where the higher altitude photos above were shot, I was on asphalt the rest of the way, as I was the entire return trip home. I remember being a little shocked when I hit reserve before getting back to Franklin where I stopped to fill up. But by that time I was exhausted and ready to get home so didn't bother checking the mileage. My general impression though, is that the TW returns better fuel mileage at lower speeds off-road, even when being ridden semi-aggressively, than it does while running at higher revs at a constant 55+ mph. Maybe next time I'll do a better job tracking my fuel consumption....
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  14. jlynch

    jlynch Adventurer

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    Hello all,
    Carb comment. I could be wrong but I don't think you need to put a spacer in under the needle with the procycle kit. I had a carb problem yesterday with my buddy's bike. Would not take any throttle and would only run on choke. Turned out that the pilot jet was clogged (shocker), but also the needle had scum on it and was ''stuck" in the main jet tube not allowing the slide to move. Never had that problem happen before. Always something with bikes.
    Got in a little ride up in the hills of Santa Monica yesterday. Sorry no pics. Next time.
    Have fun everyone.
  15. RCEMT-P

    RCEMT-P Been here awhile

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    I think tonight I'm gonna pull that shim. One thing at a time. They said start at 125 main I kept hearing everybody went 130 so I went that way. It's very low in the throttle so I'm doubting it's in the main. I'm putting my money on needle
  16. Randy

    Randy Long timer

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    My guess is the needle as well. I just suggested fine tuning the fuel screw first as it can be done with no disassembly, AND it's always best to start at the bottom and work your way up as each circuit feeds fuel to the next in the overlap areas. It's best to use a logical and systematic approach to carb tuning. A little rich or lean on the idle circuit will be adding to, or taking fuel away from, the transition area of the pilot to the needle circuits. Changing this and then changing that can have one chasing their tail without ever hitting on the perfect combination.

    When I'm sorting a carb, I use White Out (remember that stuff from the days of typewriters? Yes, I'm that old... :gerg ) to make marks on the throttle side grip flange at 1/4, 1/2, and 3/4 throttle openings and do plug chops for each throttle setting. This gave me a good indication of where to start making changes. That combined with a good ear and feel for what the engine is doing, allows one to make educated changes to get things dialed in. Of course, this was for when I was starting from scratch and trying to get the fueling dialed in. Been a while since I've had to set up a carb from scratch though.

    On my setup I'm using two needle shims. One may have done the job, but I tried two initially and since the bike runs perfectly I said, "good enough". I never even did a plug chop to verify that it was spot on so it could be running a bit rich. :dunno But it pulls cleanly all through the rev range at all throttle settings, so I'm good. :thumb

    The main only controls fuel flow at WOT, with some smaller affect from ~ 3/4 on up to WFO, so your symptoms won't be affected by it. Your symptoms are occurring in the idle circuit to needle circuit overlap area. That's not to say that you actually need a 130 main. The only way to really know for sure is to do some plug chops at WOT and see.
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  17. frog13

    frog13 Long timer

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    Try putting back in the OEM pilot.
    Can't recall the "shim stack" for the needle. On the tw200forum.com there is a sticky.
    Your correct on the 130 main.....IMO
  18. Randy

    Randy Long timer

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    Not @Mi0 but it looks like a Pirelli MT43. Similar in tread design at least, to the Shinko 241 that I used before getting the Tusk DSport front tire. Although, the MT43 is a higher end tire so may or may not perform the same as the 241. :dunno
  19. NJ-Brett

    NJ-Brett Brett

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    8 hours on a TW is a long time.
    I have done 120 miles in about 4 hours and everyone was tired at the end (group of 4).

    As far as MPG goes, ride the TW hard and you can get as low as about 50, ride it easy and gently and you can get 80 or more.
    By gently I mean 45 mph in 5th gear or slower and getting there gently.
    60 mph actual is riding it hard, like 90% power.
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  20. Randy

    Randy Long timer

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    Yes, it is! And at least 5-6 hours of that time was spent hooning along dirt roads at a good clip, some of which were just semi-maintained, and most of which were rough as hell. So, there was a bit of sitting, and a lot of transitions from seated to standing. Once again, I was reminded that the TW's suspension really isn't intended for hard use... Then again, the limitations of the suspension, and the power, is the one thing that keeps my inner hooligan in check, so it's not necessarily a bad thing in the end. And, the other attributes of the bike, like low seat height and fat ass tires... Well, let's just say that it was a very good way in which to beat the hell out of myself for the better part of a day... :D REALLY looking forward to doing it again! :ricky
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