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About LotsaBS

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    Obviously, motorcycles. Formula 1, all types of auto racing. Kart racing. Computer Racing Sims. Golf (yeah golf!)
  1. Thx for the link. I just got back from my first ride since I checked the needle and main jet and put everything back together again. I have a new problem now. Although it seems to run (and cruise) well now, I have an idle problem. Seems that it wants to idle up to around 3200 rpm when I let off the throttle and won't idle down for about 20 seconds or so. I readjusted the throttle cable linkages (didn't help) and it seems that when the bike isnt running (can't tell when the bike is running because the fuel tank is in the way) that the cable wheel on the carb is hitting the stop and there is just a little slack in the cable when the throttle grip is at the idle position. I must have done something wrong when I tore it down or put it back together. The only things I tampered with were what you outlined earlier to determine the needle and main jet sizes. But I did have to unhook the throttle cable to rotate the carb enough to take the top off. Any ideas on what else to check? Update: I thought I would go out and check for the obvious vacuum leak. Bike fired right up and idled properly. Revved the engine and it would fall back to a normal idle-like it was magically fixed. Went ahead and sprayed some ether around the carb (thinking I may have a vac leak around the intake boot between the carb and engine, but didn't find anything abnormal)...it seemed magically fixed. Didn't have a chance to ride it again tonite. May try again tomorrow. Update #2: Went out to start it again this morning. Idle problem is back. Didn't want to start without the choke. Then fired right up. Had to get some temp in the engine before it would idle without the choke. Even then the irregular idle was back. When accelerating and letting off the throttle the engine doesn't want to fall back to idle unless you drag it down by leaving it in gear almost to a stop. Even then blipping the throttle runs the idle back up and it doesnt want to settle down for 20 seconds or so. Can't find a vacuum leak. Also very slight wiggle of the idle speed screw will drop the idle. Something is hanging up, but I can't figure out just what yet. BTW, what is this business about having to adjust the slide to a proper setting I have read about? I didnt see any way to adjust the slide in my carb. See the exploded view from Sudco: http://www.sudco.com...alogJPG/029.jpg for the rest of my questions. Anyway, I did have to unscrew the link arm (#16), remove the slide or Throttle valve (#19) and the vacuum release plate (#21) to be able to unscrew the allen holding the needle in place. Whoever put it in had it torqued so tight I couldnt loosen it while still in the carb. And when I look at the exploded view of the carb there is supposed to be an o-ring type piece between the slide and the Vacuum release plate called a seal (#22). There wasn't one, but the Vacuum release plate had a circular raised area that made it fit into the slide snugly...what's up with that? Finally, when I order some additional jets, which sizes would you suggest? Do I need a leaner or richer main jet when I use the quiet insert in the exhaust? As much as I hate to , I will prob keep the quiet insert in the MRD/SSW most of the time just to keep the neighbors happy and the locals off my back...
  2. I don't have any extra keihin jets (where can I get them?), but the prev owner provided a box of dynajets. I assume that they are dynajets as they are all marked "DJ xxx". They are also round with a screwdriver end instead of hex head like the keihin ones. He upgraded the original Mikuni carb before adding the FCR. I checked a cross reference table and found that a dynajet 142 is roughly equivalent to a keihin 155. I have a "DJ 142.5" in the box. Next question is will the dynajet thread onto and work with the keihin needle guide?
  3. Finally got a chance to tear down the carb today and find out what was inside. Looks like the needle is an EMN. It was marked "OCEMN" and the clip was placed in the 3rd notch from the top. Since I've never torn down an FCR (there is almost NO room to work when it's still installed on the bike! arrrrgh!) it was quite a learning experience. The main jet was marked "AB158". I assume that means it is a 158 instead of the standard 160. Had a hell of a time putting everything back together as I was working with so little room, but finally got it done. I may still have to adjust the throttle cables some as I had to undo them to be able to tilt the carb enough to be able to get to the needle. I may have them a little too tight as I'm now having a tough time getting the idle just right again. Anyway it's back together and running. I still think it may be just a little bit rich. Below are the main performance mods: Athena Big Bore Hot cams stage 1 3X3 Mod FCR39MX (EMN needle and 158 Main jet) MRD/SSW with quiet core installed (the bike may have been originally tuned without the quiet core) My elevation is 1000-1200 feet. Again, thanks for everyone's help, especially you Craigo! Let me know what you think.
  4. Forgot we had to go out of town to a wedding this weekend. Didn't get back home till a couple of hours ago, so I didn't have much time to mess with the bike or pull the jets. I did drain the fuel (had just a little left over from the prev owner) and refilled the tank with some fresh 91 octane a little while ago. Also sprayed some Berryman chemtool cleaner thru the carb. I just got back from a quick ride and between the plug change the other nite and the fresh fuel, the bike runs much better. The periodic "miss" or hesitation seemed to be gone. The only thing I noticed was that the point between the idle circuit and acceleration was still a little rough. I think it may still be a little rich. Hopefully I can check the jets in the next few days. Craigo, I'll let you know what I find out. I really appreciate your help. Meanwhile, here are a couple of pics of the bike.
  5. Thanks for the info! I will try to look at that tomorrow nite or this weekend. I really appreciate your help!
  6. You say it's an FCR-MX?. How can you tell one version from another? I'm trying to learn. I know it does not have any electronic connections attached. If I can't cure the minor "miss" at cruising speeds otherwise, I may have to re-jet it. Where can I find the best procedure to (1) pull the carb out if necessary, and (2) who do you guys recommend to purchase other jets and parts for it?
  7. Don't yet know what version the carb is. Here are a few pics that may identify it. Didn't have much time to mess with it tonite, but did pull the sparkplug. It was pretty clean, no carbon build up (NGK-CR8E at .030). It was dark charcoal around the electrode, but the last several miles have been quite slow and alot of idle time adjusting the carb. The electrode itself looked pretty good as it was brownish with no build up or deterioration. Went ahead and replaced it with the identical plug so I have a better gauge going forward.
  8. As of yesterday, I tweaked both the mixture and the idle, following instructions I found here on the forum. The bike initially idled too slowly (1000-1200 rpm) and had a hesitation off idle when blipping the throttle. I ended up with the mixture screw at 2 1/4 turns out from seated and the idle speed an additional half turn in (to increase the idle speed) from it's initial position. It now idles consistently at around 1650-1750 rpm and there is no hesitation off idle when blipping the throttle. Interestingly, when adjusting the mixture screw, the engine didn't die until it was about 1/8th turn from fully seated. The bike responds quite well, with the exception of the periodic minor "roughness" or miss during cruising at a specific speed. This same "roughness" or miss also happens when the bike is parked, in neutral and holding the engine at a cruising rpm. It is not enough to vary the rpm by 1-or 200 revs but there is a definite periodic miss going on that you can feel and hear. You also notice it when holding the bike at cruising speed (40-50 mph).
  9. Yes, it does have the 3 X 3. This bike is highly modded: Athena 440 Big Bore 3 X 3 mod Keihin FCR 39 (not sure which version) Hotcams Stage 1 MRD SSW exhaust (quiet plug installed) Vapor Gauges Rental Bars Michelin Pilots Acerbis brush guards ASV levers LED turn signals and brakelites Galfer Brake lines DRC Silicone Radiator hoses yada yada yada I purchased it from an AirForce Instructor Pilot. He took great care of it and said that he was selling it because they had another child on the way and were getting transferred to another airbase.
  10. The bike did come from out of state, but the elevation difference is less than 1000 feet. I was planning to pull the fcr39 carb out, but am still looking for the best procedure to do so. I am not certain which model I have and will try to post pics later today. I guess I have to upload to an image hosting site and post the link in my message?
  11. Nope, seems to rev fine. Just that slight bobble when crusing or holding a specific rpm when in neutral. No big backfires on deceleration either (although it does backfire a little bit sometimes on deceleration). Maybe this is not carb related? I could change out the spark plug and try that. Not sure of the proper gap though (previous owner lost the manual).
  12. Been lurking for some time and recently bought an 09 DR-Z400SM. It was heavily modded with Athena 440 Big Bore Kit, FCR39, HotCams Stage 1, and MRD SSW Exhaust. The bike is in great shape, and I'm told that the mods were done by his local dealer. However, when I got the bike, the carb tuning was a little off, causing the idle to be very slow (around 1000-1200 rpm) and a creating bog-hesitation upon off-idle acceleration. I was able to cure that by tweaking the fuel mixture and idle speed. I followed some instructions found here on the forum (thanks!) and now I have a smooth idle of around 1650-1750 and instant acceleration. BUT, when trying to ride at a constant cruising speed there is a persistent, minor hesitation or bobble. It isn't bad enough to effect your speed, but you can feel and hear it. You can also duplicate it when the bike is in neutral. For example, when you hold the engine at a specific rpm when in neutral it does not run really smooth, but runs at that rpm with a slight bobble. This occurs at almost any cruising rpm, but seems to disappear when the bike is at idle. Any ideas on how can I get this smoothed out? I'm hoping I don't have to pull the carb, as it is wedged in very tightly. Also how can I tell which model FCR I have? I'd attach pics, but have not figured out how... Thanks in advance.