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02-10-2010, 11:29 AM treybrad Joined on 02-06-2010 PF, TX Posts 86 Round Slide Carb Tuning Attachment: carb.jpg I tried searching but didn't come up with an answer, hopefully this hasn't been covered a million times already. Just bought a '97 CA model TW. It runs well, but I think it might be a touch lean as it likes to 'hunt' a bit at steady cruise around 40-50mph. I've found some fantastic tutorials on carb tuning, like this one: http://tw200forum.com/forums/1/28873/ShowPost.aspx#28873 but I'm pretty sure that's not my carb... Mine looks like the attached picture I stole from an eBay listing. I've plugged the port on my CA model's carb (where the screw is in the picture) since I removed the EVAP cannister. I'd like to order parts, a selection of main jets, washers, etc, but if the carbs are totally different, I'd be ordering the wrong parts I imagine. Is there a tutorial for these older models or is it just the nature of the beast to run a little lean and deal with it? Starts easily and warms quickly, seems fine on the hwy. Maybe I should just leave well enough alone...? trey '07 Suzuki Bandit 1250SA '97 Yamaha TW200    Report

02-10-2010, 1:36 PM Nikita Joined on 08-21-2009 Running Springs, CA USA Posts 18 Re: Carb Changes by Year You have an "early" bike, vs the "late" model shown in the post referenced. There are many changes on the 2001? model year, the carb being one of the major ones. I have not yet started to "tune" my '90 but will eventually do so. First, before messing with the carb, put in a new or regapped correct spark plug, clean the air filter and adjust the valves. Now others may direct us to a thread on tuning the early carb, but for now, without changing any jets, just raise the needle one step if possible and see if that makes you happy. Since the bike is currently at sea level and I plan on operating it mostly at 6000ft MSL, I'm going to hold off until then.    Report

02-10-2010, 1:53 PM Broken Veteran Joined on 09-12-2009 Sebring, Florida Posts 227 Re: Carb Changes by Year From what I have gathered. Only two carbs. Non-CV Carb has the part the throttle cables attach to on the left side. CV carb has the cables in the right side. The exact time of the change I am not sure. Older bikes have the cables on the left and a drum front brake and a kick starter. Newer bikes have the cables on the right and a disc front brake and no kick starter. That is my observation. But then again, California is a deviation from the norm.  I am from San Diego.  I am allowed to say that. This is a non-CV, non California, 1987 Carburetor.    Report

02-10-2010, 5:33 PM treybrad Joined on 02-06-2010 PF, TX Posts 86 Re: Carb Changes by Year Nikita - Gotcha. So there's only two versions, that's good... thought there might have been a few upgrades along the way. I actually already had the bike apart waiting for it to cool overnight so I could check the valves. They were a little loose, so I snugged them up to the tighter side of spec, but they weren't too loose -- maybe it'll help though. Air filter is clean, popped in a new spark plug (double checked the gap). I just took it for a spin around the block, but it's in the 30's and raining/sleeting here, so I didn't go for a long ride. Maybe my mini tune up will help. Broken Veteran - That's mine -- non-CV, early model. Not sure why mine is a CA model. I'm in Texas, so I guess it was originally from CA. Funny thing is, the last owner supposedly replaced the whole carb assembly and he bought the CA carb as well. First thing I did was take off the EVAP can and cap that port on the carb. I have no idea what else is different inside the carb -- I may take it apart soon just to have a poke around. Thanks for the help so far -- if anyone has specific tips on tuning the 'old' carb, I'm all ears... trey '07 Suzuki Bandit 1250SA '97 Yamaha TW200    Report

02-10-2010, 7:47 PM TW-87 Joined on 02-01-2010 Manitoba, Canada Posts 305 Re: Carb Changes by Year I have some photos of the older carb from my '87 (Canadian) model. They might help. All the parts have tha Yamaha names on the MrCycles website if your're curious about what is called what. See: http://www.mrcycles.com/fiche_section_detail.asp?section=8133&category=Motorcycles&make=YAMAHA&year=1987&fveh=218 I'll post a few photos for you. TW-87 1987 TW200, 15/44 sprockets, DID O-ring chain, Award winning, "Quick Release" Action Packer :-))    Report

02-10-2010, 8:09 PM TW-87 Joined on 02-01-2010 Manitoba, Canada Posts 305 Re: Carb Changes by Year This is the 1987 carb looking at the choke side. TW-87 1987 TW200, 15/44 sprockets, DID O-ring chain, Award winning, "Quick Release" Action Packer :-))    Report

02-10-2010, 8:12 PM TW-87 Joined on 02-01-2010 Manitoba, Canada Posts 305 Re: Carb Changes by Year Kickstarter side TW-87 1987 TW200, 15/44 sprockets, DID O-ring chain, Award winning, "Quick Release" Action Packer :-))    Report

02-10-2010, 8:14 PM TW-87 Joined on 02-01-2010 Manitoba, Canada Posts 305 Re: Carb Changes by Year Inlet side TW-87 1987 TW200, 15/44 sprockets, DID O-ring chain, Award winning, "Quick Release" Action Packer :-))    Report

02-10-2010, 8:17 PM TW-87 Joined on 02-01-2010 Manitoba, Canada Posts 305 Re: Carb Changes by Year Outlet side TW-87 1987 TW200, 15/44 sprockets, DID O-ring chain, Award winning, "Quick Release" Action Packer :-))    Report

02-10-2010, 8:25 PM TW-87 Joined on 02-01-2010 Manitoba, Canada Posts 305 Re: Carb Changes by Year Bottom view with the bowl removed. Ignore the parts on blue paper. They are new (duplicate) replacements for the pilot screw assy and the needle valve assy.  The parts between the blue papers are more or less lined up with the holes they fit into. Note that I previously removed the plug which covered the pilot screw. See other posts about this procedure. TW-87 1987 TW200, 15/44 sprockets, DID O-ring chain, Award winning, "Quick Release" Action Packer :-))    Report

02-11-2010, 6:23 AM treybrad Joined on 02-06-2010 PF, TX Posts 86 Re: Carb Changes by Year TW-87 -- Thanks for the info! I can only get the 1st picture to pull up, none of the rest. I'd love to see the rest of them though... trey '07 Suzuki Bandit 1250SA '97 Yamaha TW200    Report

02-11-2010, 7:28 AM TW-87 Joined on 02-01-2010 Manitoba, Canada Posts 305 Re: Carb Changes by Year I'll try again. Note to self: Copy Image (and Paste) doesn't work here ! TW-87 1987 TW200, 15/44 sprockets, DID O-ring chain, Award winning, "Quick Release" Action Packer :-))    Report

02-11-2010, 7:33 AM TW-87 Joined on 02-01-2010 Manitoba, Canada Posts 305 Re: Carb Changes by Year Kickstarter side TW-87 1987 TW200, 15/44 sprockets, DID O-ring chain, Award winning, "Quick Release" Action Packer :-))    Report

02-11-2010, 7:35 AM TW-87 Joined on 02-01-2010 Manitoba, Canada Posts 305 Re: Carb Changes by Year Inlet side TW-87 1987 TW200, 15/44 sprockets, DID O-ring chain, Award winning, "Quick Release" Action Packer :-))    Report

02-11-2010, 7:36 AM TW-87 Joined on 02-01-2010 Manitoba, Canada Posts 305 Re: Carb Changes by Year Outlet side TW-87 1987 TW200, 15/44 sprockets, DID O-ring chain, Award winning, "Quick Release" Action Packer :-))    Report

02-11-2010, 7:46 AM TW-87 Joined on 02-01-2010 Manitoba, Canada Posts 305 Re: Carb Changes by Year From bottom with bowl removed. Original parts are on the white backgound, with (from left) the pilot screw, jets, and needle valve parts roughly lined up with the 4 holes they go into. A new needle screw assy. and a new needle valve assy. are shown on the blue background. No, these new parts did not fix my ignition problems, in case you were wondering, but they did take $100 CDN away from my new CDI budget. I'm telling myself that after 23 years they probably needed replacing, anyway, right ? TW-87 1987 TW200, 15/44 sprockets, DID O-ring chain, Award winning, "Quick Release" Action Packer :-))    Report

02-11-2010, 8:13 AM treybrad Joined on 02-06-2010 PF, TX Posts 86 Re: Carb Changes by Year Ah, those worked. Thanks for the pictures, good to know just what's in there... Think I'll pull it out and make sure it's nice and clean when I have some down time and see if that helps at all. I'll try shimming the needle up a bit if not. trey '07 Suzuki Bandit 1250SA '97 Yamaha TW200    Report

02-17-2010, 5:09 AM treybrad Joined on 02-06-2010 PF, TX Posts 86 Re: Carb Changes by Year Well, here's an update with where I'm at. I still haven't found any good info on tuning this carb specifically, so I'll try to chronicle my luck as best I can. I popped out the pilot screw cover and adjusted it out a few turns and it seems to have helped tremendously. 2.25 turns is where I set it up initially on my work bench, that was too lean. I've backed it out some more, probably close to 3 full turns, but I can't be sure as all I can get is a little screwdriver attachment and turn it 1/8 a turn at a time. I'll find the exact number of turns next time I have the carb off the bike. It's still a little lean cruising steady, but much better. A nice steady cruise on flat ground is smooth, but on a slight decline I get some surging still. Here's my question for you guys -- I can raise the needle on this carb to accomplish the same thing as you would with a CV carb, correct? IE - fatten up the mixture at mid-throttle openings. It's completely different vs. a CV carb under the top cover, and I didn't dismantle anything other than taking off the cover to take a peek, but looking at the fische, it seems like I could find a washer and stick one or two under the needle just like you would on the CV carb. Another question -- I get pinging pretty loudly under heavy/full throttle. If I wind out a gear at full throttle, you can hear a very noticeable ping/knock. I assume this is because my main jet is too small as well, correct? Easy enough to fix, but I want to verify that is a valid theory before I go to the trouble and screw something up.... Overall the bike runs really well, and I'm being picky to iron out the last details. It starts much better now with the pilot screw adjusted, and as long as I stay off full-throttle, it's close to perfect... Thanks for any help, trey *edit* Also of note, the valves are recently adjusted, the air filter is clean and oiled, and a new spark plug was just put it -- so those things are all taken care of. '07 Suzuki Bandit 1250SA '97 Yamaha TW200    Report

02-17-2010, 8:11 PM treybrad Joined on 02-06-2010 PF, TX Posts 86 Re: Carb Changes by Year Found some good info tonight Googling around... http://www.advrider.com/forums/showpost.php?p=7907558&postcount=149 The XT350 shared the same main jets -- verified by matching part numbers from the fiche online. The 288-14343-57-00 is the stock 114 main, 288-14343-58 is a 116, 288-14343-59 is a 118, etc, etc. That link has a whole chart of jets. It's good to have part numbers in case you get some doofus at the parts counter, or if you need to order them online. TW-87, there's no pictures of the top end of your carb dissected, but does the needle have notches for the clip? I read on another site that it did on these older Mikuni carbs, so that would be good. I'll probably tear into my carb again tomorrow and try and raise the needle and find a bigger main jet. Anyone have a suggestion on what size main to get? I'm stock exhaust/intake, 0-2,000ft ASL so altitude is a non-factor. I figure I'll just go up one step since it runs well excepting the pinging at WOT. trey '07 Suzuki Bandit 1250SA '97 Yamaha TW200    Report

02-17-2010, 8:56 PM TW-87 Joined on 02-01-2010 Manitoba, Canada Posts 305 Re: Carb Changes by Year Sorry, no. There were no adjustment notches in my needle. Based on previous posts, it sounds like lots of folks have found that adding some thin washers under the circlip worked well for them to make the mid throttle range a little bit richer. I have not had a reason to do so. I did, however, add a small o-ring above the circlip to add a little more pressure to the spring that forces the needle down when the throttle is closing, based on an older post. On hindsight, I think that was a waste of the o-ring, but I'm quite sure it won't do any harm, and you know, "hang the expense". My T-dub really deserves the little extras. TW-87 1987 TW200, 15/44 sprockets, DID O-ring chain, Award winning, "Quick Release" Action Packer :-))    Report

02-18-2010, 2:11 AM WINGNUT200 Joined on 01-16-2009 St. Paul Posts 65 Re: Carb Changes by Year Jeepers that sure is a nice one For those about to rock!    Report

02-18-2010, 7:09 PM TW-87 Joined on 02-01-2010 Manitoba, Canada Posts 305 Re: Carb Changes by Year Thank you. I assume that you're talking about my carb photos. I cleaned it three times, each time going in a little deeper, before I took the photos. I finally figured out my problem is in the stator coil. However, I did pull 23 years worth of crud out of the carb , learned a lot and had a lot of fun in the process. TW-87 1987 TW200, 15/44 sprockets, DID O-ring chain, Award winning, "Quick Release" Action Packer :-))    Report

02-19-2010, 8:15 AM treybrad Joined on 02-06-2010 PF, TX Posts 86 Re: Carb Changes by Year Well, I ordered a 115 and a 120 from this place since they were only a couple of bucks: http://powersports360.com/eshopprod_cat_5326-5990-5414_product_678286_keyword_mikuni+AND+small+AND+hex.GENUINE_MIKUNI_SMALL_HEX-TYPE_.htm Hopefully that's not a mistake and I won't have to order the $11/ea jets from Yamaha in the end anyway... I cleaned the carb last night, it looked to be spotless in there, but I gave everything a good spray with carb cleaner anyway. Using the 'tube method', my float height is a tad high -- level with the base gasket from the bowl/main body, but if anything that should make me a little rich from what I understand. No leaks or overflow, so I think it's fine. I decided against shimming the needle until I get the new main jet in and seeing what it does. Since no one else has shimmed theirs, I hesitate to unless it's a problem still with the new main. My pilot screw was way out -- close to 4 turns. I backed it up to 2.75 turns out, we'll see how she runs next week when I get a chance to play with her. trey '07 Suzuki Bandit 1250SA '97 Yamaha TW200    Report

02-19-2010, 9:57 AM TW-87 Joined on 02-01-2010 Manitoba, Canada Posts 305 Re: Carb Changes by Year Sounds like a plan ! BTW if you decide to fool around with the float height, I think I stumbled upon a fairly reliable method to adjust the floats to spec. without "compressing" the needle valve ( as they say in the manual). The fuel height spec. is very tight. I tried to put 2 scratches on the side of my carb at the maximum and minimum heights specified, and they ended up merging into one wide scratch. I described this method in more detail (with photos) on this thread: http://tw200forum.com/forums/4/67113/ShowPost.aspx#67113 The description is on page 4, posted Feb.14 if you're interested. TW-87 1987 TW200, 15/44 sprockets, DID O-ring chain, Award winning, "Quick Release" Action Packer :-))    Report

02-19-2010, 11:35 AM treybrad Joined on 02-06-2010 PF, TX Posts 86 Re: Carb Changes by Year Great tip TW-87, thanks! I'll double check when I'm installing my new main jet (hopefully soon). trey '07 Suzuki Bandit 1250SA '97 Yamaha TW200    Report

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