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Remember to clean your needle and buff it up with some aluminum foil, and check up whether your needle is shimmed up or down correctly. If your needle is still at stock height with all that stuff installed, you probably need to bump up the needle by 1 position/1 shim. If it's already bumped up a shim from stock, leave it alone. If your needle has rough spots anywhere, go ahead and figure on replacing it. Double-check your slide boots too, that shouldn't technically keep you from starting but weirder things have happened. Do not let carb cleaner ANYWHERE near them, it causes boots to deform, degrade, and consequently cost you a bundle replacing them. Here's the PDF from DynoJet for your bike, I'd double-check EVERYTHING in there if the PO installed the kit and not you: http://www.dynojet.com/pdf/2153.pdf e: Also if you aren't checking all 4 cylinders for gas smell/everything, bite the bullet and start working sequentially. The way you're wording things it sounds like you're just sampling one cylinder, if this is true you're likely missing something occurring in the other ones. If you are repeating the same steps in all four, then nevermind. If it were running too rich, it ought to be reeking of gas inside the cylinder after cranking it a few times without firing, perhaps even leaving some liquid gas on the spark plug tips. If it's just a faint smell, then you might be running too lean for the burn to do enough work to keep the engine going. If it ran crappy while cold on 2.5 turns, set it at 3 when you button everything back up. Are you 100% positive you're getting spark on all plugs? As in, you've checked every one of them against the cylinder head to make sure there's a nice strong blue spark? Do it in a dark garage if you aren't already, makes it a lot easier to tell the strength of your spark. Kilersquirrel fucked around with this message at 15:50 on Apr 11, 2013 |
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Apr 11, 2013 15:44
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Rev. Dr. Moses P. Lester posted:At our shop we've seen a lot of 70s/80s bikes, most often Japanese fours, showing this symptom, and not a lot of them are actually due to intake leaks. It can be a complete bitch to solve the issue. Some of the worst offenders are the old Honda mechanical slide carbs. The cause is similar to an intake leak though, it's running lean due to reasons that are hard to specifically track down. Assuming it's just wear on the moving parts in the carb which lets too much air through. Upping the idle jet usually fixes it, but a disturbing number of those bikes have pressed-in idle jets which basically can't be changed. Which moving parts on a carb wear out to let in more air? If you're intake boots show no cracks, are soft, etc., check the intake O-rings (if you have them). The intake boots on my Suzuki are rubber boots with a metal base that contacts the head. So they have a rubber o-ring there. That ring gets hard and flat, and leaks air, even if the boot itself is good to go. If you have vacuum ports for synching the carbs, check those as well. A missing or badly fit port cap will puke air into the mixture. Check your airbox for cracks or bad seals. Throw some weather stripping to seal up side covers of the airbox (if applicable) Finally, check your air-filter for oil. If you use a filter that needs to be oiled (not a paper filter), it can dry out and allow more air.
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Apr 11, 2013 16:35
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Kilersquirrel posted:Remember to clean your needle and buff it up with some aluminum foil, and check up whether your needle is shimmed up or down correctly. If your needle is still at stock height with all that stuff installed, you probably need to bump up the needle by 1 position/1 shim. If it's already bumped up a shim from stock, leave it alone. If your needle has rough spots anywhere, go ahead and figure on replacing it. Double-check your slide boots too, that shouldn't technically keep you from starting but weirder things have happened. Do not let carb cleaner ANYWHERE near them, it causes boots to deform, degrade, and consequently cost you a bundle replacing them. If bike turns over, but doesn't start, check the plugs. If wet - spark issue. If dry - fuel issue. You said you have good spark, and I assume you mean across all four plugs. Did you check your ignition timing? Are you sure the leads did not get crossed when you checked or replaced the plugs?
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Apr 11, 2013 16:39
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GnarlyCharlie4u posted:So I just brought home a 99 VFR800 on friday. See my other reply re: the VFR - full systems barely exist and are no benefit over the stock header systems. See the vfr forums if you're really obsessed with it.
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Apr 11, 2013 17:25
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BigMcLargeHuge posted:There is a slight smell of gas, but it isn't very strong. The last few times I've tried starting the bike has been with the tank to the side, with the hose connected to the fuel pump and no air box attached. I did set the pilot screw to 2.5 turns out, which is where it was when I first opened the carb up. I forgot to mention that the PO did install a Dynojet Stage 1 kit and Vance & Hines exhaust. My suspicion is that it's running too rich, but I'm not sure where to start to change that. I'm going to finish taking the carb apart tonight and clean everything again to see if that changes anything. Choke? If he didn't get the jetting right, it might be hard starting for a lot of reasons, likely that it's actually too lean (if he didn't replace the pilots and then put a full system on it). Pair that with no intake restriction, and bam, starting gets really hard. Also, hotwire the pump (carefully) with a jumper lead to fill the carb bowls in advance (hot lead off positive on the battery to the red wire on the fuel pump connector) or you'll sit on the starter for 30+ seconds while the pump goes. Also it's going to be extra lean if you're pumping a bunch of fuel in there with the floats too low, so if you're too aggressive with trying to start it with throttle while it's still filling the bowls it'll take even longer to start. Some throttle often helps on start too, but not too much or you'll lean it out. Maybe 10%. Also make sure when you reinstall the airbox once you get it running you don't knock the coil leads off...it's easy to do. Z3n fucked around with this message at 18:05 on Apr 11, 2013 |
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Apr 11, 2013 18:03
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While we're all on, anybody got an opinion on whether I should break out the compression tester straightaway, or look elsewhere first for the cause of my mysteriously sooty plugs?
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Apr 11, 2013 18:31
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Kilersquirrel posted:While we're all on, anybody got an opinion on whether I should break out the compression tester straightaway, or look elsewhere first for the cause of my mysteriously sooty plugs? Wouldn't worry too much about it.
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Apr 11, 2013 18:37
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Kilersquirrel posted:While we're all on, anybody got an opinion on whether I should break out the compression tester straightaway, or look elsewhere first for the cause of my mysteriously sooty plugs? If your plugs are sooty, compression is not the likely suspect. It's either rich mixture or weak/poorly timed spark.
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Apr 11, 2013 19:12
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It's just the front cylinder that's sooty, the rear cylinder plugs are perfect light brown. But that's good, thanks. There's a decent chance the PO tried to do the home 8* timing advance mod and messed up the spark timing for one ignition pickup. E: he did drill out part of the tailpipe baffles to "make it sound more like a Harley," so a kinda-hosed DIY-timing advance job is pretty likely now that I stop and think about it. Kilersquirrel fucked around with this message at 20:49 on Apr 11, 2013 |
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Apr 11, 2013 19:47
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Rev. Dr. Moses P. Lester posted:Thanks but that doesn't answer my question. Is there a slide in there? Look at the link. It clearly shows you there is a conventional butterfly plate inside. The cleverness is that it looks just like a carb without being one.
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Apr 11, 2013 20:22
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Pfft. Even I knew that about the "carburetors" on the new Triumphs and I know hardly anything about motorcycles. Then again I commented on it to one of the sales guys at a motorcycle place (not Triumph specific, but they had two on the floor) downtown here and he didn't know either, soo
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Apr 11, 2013 20:37
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Rev. Dr. Moses P. Lester posted:At our shop we've seen a lot of 70s/80s bikes, most often Japanese fours, showing this symptom, and not a lot of them are actually due to intake leaks. It can be a complete bitch to solve the issue. Some of the worst offenders are the old Honda mechanical slide carbs. The cause is similar to an intake leak though, it's running lean due to reasons that are hard to specifically track down. Assuming it's just wear on the moving parts in the carb which lets too much air through. Upping the idle jet usually fixes it, but a disturbing number of those bikes have pressed-in idle jets which basically can't be changed. On my old Suzuki GSX600F (Katana) with Mikuni BST31SS carbs, I had what seemed like a textbook intake leak. Only after having taken it apart and put it together several times, putting in more and more new parts, it didn't get better at all. In the end, the fault was the o-rings behind the pilot screws. As they get old and hard they let air past, loving up your fuel mixture in a way very very similar to an intake leak.
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Apr 11, 2013 21:30
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Nidhg00670000 posted:On my old Suzuki GSX600F (Katana) with Mikuni BST31SS carbs, I had what seemed like a textbook intake leak. Only after having taken it apart and put it together several times, putting in more and more new parts, it didn't get better at all. In the end, the fault was the o-rings behind the pilot screws. As they get old and hard they let air past, loving up your fuel mixture in a way very very similar to an intake leak. Because those hardened o-rings leak air, you see.
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Apr 11, 2013 21:55
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Well, they do shrink as they age and harden, so yeah it's pretty plausible. Cracking from vibrations in the embrittled rings would allow air to get by as well, it's not like they're torqued down and squashed into every nook and cranny of the metal, smooth as it may be.
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Apr 11, 2013 22:41
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Kilersquirrel posted:Remember to clean your needle and buff it up with some aluminum foil, #0000 steel wool works better imo. n8r posted:See my other reply re: the VFR - full systems barely exist and are no benefit over the stock header systems. See the vfr forums if you're really obsessed with it. That's what I've been finding so far. Nothing besides Delvetic and I seen no reason to swap the stock exhaust for a stainless. Oh well... there go my hopes for a full-system Ti exhaust.
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Apr 12, 2013 00:38
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Snowdens Secret posted:First I heard of the no-touch-em-2013 thing. Looks like there's a big warning banner at the top of the page at http://www.tuneecu.com/
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Apr 12, 2013 00:44
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Tamir Lenk posted:Which moving parts on a carb wear out to let in more air? Slavvy posted:Look at the link. It clearly shows you there is a conventional butterfly plate inside. The cleverness is that it looks just like a carb without being one.
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Apr 12, 2013 01:13
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Rev. Dr. Moses P. Lester posted:Any/all of them. Butterfly shaft, slide, butterfly plate. I dunno this for sure but it was a plausible explanation offered by an MMI instructor. I see literally no reason why an EFI system would need a slide, it makes no sense. I'd say it's all just illusion.
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Apr 12, 2013 01:33
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Slavvy posted:I see literally no reason why an EFI system would need a slide, it makes no sense. I'd say it's all just illusion. Goddamnit I wish I could remember offhand but I recently worked on a bike that had EFI but the "throttle bodies" (really just carb bodies with injectors added) had CV slides. I want to say it was a Yamaha?
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Apr 12, 2013 02:16
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GnarlyCharlie4u posted:Goddamnit I wish I could remember offhand but I recently worked on a bike that had EFI but the "throttle bodies" (really just carb bodies with injectors added) had CV slides. Interesting. I wonder if it was a stop-gap money saving design like it sounds, or if there's some real benefit I haven't thought of.
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Apr 12, 2013 02:49
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Slavvy posted:I see literally no reason why an EFI system would need a slide, it makes no sense. I'd say it's all just illusion. I'll say it again. Early R6's had vacuum slides. With EFI. I think I've mentioned this before.. in the last week. Yeah, to you. http://forums.somethingawful.com/showthread.php?threadid=2975471&userid=0&perpage=40&pagenumber=507#post414301794 Slavvy posted:Interesting. I wonder if it was a stop-gap money saving design like it sounds, or if there's some real benefit I haven't thought of. Nerobro fucked around with this message at 05:06 on Apr 12, 2013 |
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Apr 12, 2013 05:03
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Slavvy posted:Interesting. I wonder if it was a stop-gap money saving design like it sounds, or if there's some real benefit I haven't thought of. Cain't exist if you haven't thought of it.
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Apr 12, 2013 05:21
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Nerobro posted:I'll say it again. Early R6's had vacuum slides. With EFI. I think I've mentioned this before.. in the last week. Early R6's are carby...? Unless you mean 03 as early. I also don't see how that's at all an argument against EFI, nor did I say EFI is flawless; just better than carbs. nsaP posted:Cain't exist if you haven't thought of it. Jesus give it a rest would you.
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Apr 12, 2013 06:01
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It's not inherently better than carbs. It just depends entirely on the execution.
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Apr 12, 2013 06:10
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nsaP posted:Cain't exist if you haven't thought of it. Hey are you going to knock this dumb poo poo off or what?
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Apr 12, 2013 06:47
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Slavvy posted:Early R6's are carby...? Unless you mean 03 as early. I also don't see how that's at all an argument against EFI, nor did I say EFI is flawless; just better than carbs. 03-05 had vacuum slides on EFI. Given the R6 is now 14 years old? Yeah, you could say the 03-05 is early.
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Apr 12, 2013 06:52
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Hi Ozma you should get a motorcycle  Also don't Mazdas use a slit in their butterfly valve to help with idle instead of a TPS? It's actually kind of cool how Yamaha decided to address EFI issues with a bit of old carb tech. Knot My President! fucked around with this message at 07:22 on Apr 12, 2013 |
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Apr 12, 2013 07:20
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Nerobro posted:Computers have issues right off the bottom. But.. you believe EFI is flawless. I'll say it again. EFI is not inherently jerky. I think I've mentioned this before.. in the last week  "Computers" have no issues right off the bottom. The manufacturers programming them make the idle as lean as possible on an open-loop mode (smart, real time adjustments based on sensor data) to get good emissions and mpg numbers. The motor is barely running at this point, the computer is keeping it right on a knife edge. It's the transitioning from an ultra-lean open-loop mode to a richer closed loop (dumb) mode for acceleration makes for jerkiness. You can fix this on many bikes, like I have, by plugging in a £15 USB-to-ODB2 adapter and changing the mode-transition settings. But... you believe EFI is jerky.
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Apr 12, 2013 10:45
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ReelBigLizard posted:I'll say it again. EFI is not inherently jerky. I think I've mentioned this before.. in the last week Thanks. How many bikes actually have OBD2 nowadays? Is it mandatory for bikes yet?
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Apr 12, 2013 11:01
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So I think I'm finally going to tackle the suspension upgrades this weekend. Dropping Race-Tech emulators over old school damper rod forks which will change the specs on oil from OEM kind of a lot. I have straight-rate Race-Tech recommended springs based on bike and rider weight so I'm good there, but they only recommend Race-Tech brand oil (obviously). I don't want to wait around for shipping, but cross shopping fork oil has quickly informed me not all like-weight oils are actually like-viscosity. I just want to get the most comparable oil possible that is available locally. Has anybody used this chart or does it look reputable? http://mahonkin.com/~milktree/motorcycles/fork-oil.html Any other resources for properly comparing fork oils across weights/manufacturers very much welcome.
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Apr 12, 2013 14:45
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ReelBigLizard posted:I'll say it again. EFI is not inherently jerky. I think I've mentioned this before.. in the last week The problem with early EFI and the jerky/surging you would experience had something to do with the range of fuel an injector can spit out. When you need that teeny little bit of fuel at cracked open throttle all the way to lots of fuel at WOT stuff gets hard to setup. This was solved on some bikes by going to two injectors per intake so you had one smaller one and one larger one. Not sure how that gets solved these days, maybe injector tech has just gotten better. What bikes can you hack fuel maps with an ODB2 -> USB adapter? I've never heard of this.
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Apr 12, 2013 15:01
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Slavvy posted:Thanks. Check out the list of supported bikes by tuneecu. Those are about it. Everything else is proprietary. The difference between well set up efi and carbs is so minimal as to be irrelevant...the problems people experience with one vs. the other revolve around rhe fact that bikes arent made to have perfect response, but to pass emissions on a budget.
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Apr 12, 2013 16:02
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ReelBigLizard posted:I'll say it again. EFI is not inherently jerky. I think I've mentioned this before.. in the last week I don't believe EFI is jerky. EFI has trouble on the bottom end due to sensor resolution and injector resolution. I've done the math. It's really hard to avoid. :-) But, it can be gotten around. Using a newer version the same Example bike, the R6, which uses drive by wire, solves that. By using the computer to control the throttle opening, the changes are predictable, and can be compensated for. And as N8r pointed out, some bikes have multiple injectors, allowing for precise metering at small throttle openings. It can also be covered by being a little rich on the bottom. There's a lot of ways to deal with it. You got the open/closed loop thing backwards. Open loop is when the computer is NOT getting feedback. That's the situation virtually all EFI engines are in when they are in a power portion of their fueling maps. They only go closed loop during cruise, and idle. Closed loop is when the computer is compensating using the o2 sensor. There are several reasons why you go open loop during transitions and during large throttle openings. If you're interested, I can go into the details.
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Apr 12, 2013 16:20
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Kilersquirrel posted:e: Also if you aren't checking all 4 cylinders for gas smell/everything, bite the bullet and start working sequentially. The way you're wording things it sounds like you're just sampling one cylinder, if this is true you're likely missing something occurring in the other ones. If you are repeating the same steps in all four, then nevermind. You're correct that I did not check all 4 cylinders. I intended to do that tonight, however, upon completely taking apart the float bowls again, I found that in the #3 carb, under the air/fuel mix screw, it looks like the o-ring broke and shoved itself inside the area where the needle sits. That tiny hole, just a bit bigger than the needle point. Is there anything you'd recommend to get that the hell out of there? Tiny tweezers?
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Apr 12, 2013 16:26
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n8r posted:What bikes can you hack fuel maps with an ODB2 -> USB adapter? I've never heard of this. Tune ECU supports Triumph, KTM, Aprilia, Benelli models containing either a Keihin or a Sagem ECU. TuneBoy can also handle those brands plus Ducati, Buell, Moto Guzzi and MZ but it costs an arm and a leg and you need to buy a tuneboy cable. For BMW there's the GS-911 but it doesn't handle fuel mapping
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Apr 12, 2013 18:21
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I want to dial in my suspension a bit more - I went by the book when I got the bike, and it got me pretty drat close. However, when I hit soft dip-like bumps in the road, there's a little oscillation on the rear that I want to settle sooner; should I turn up the compression and rebound damping a little on the rear? Add some preload?
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Apr 12, 2013 19:54
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theperminator posted:Tune ECU supports Triumph, KTM, Aprilia, Benelli models containing either a Keihin or a Sagem ECU. TuneBoy can also handle those brands plus Ducati, Buell, Moto Guzzi and MZ but it costs an arm and a leg and you need to buy a tuneboy cable. Buell takes a ~$40 cable, the software is free.
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Apr 12, 2013 19:55
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So, does anyone understand the UK motorbike license stuff? I'm 21 and I'm looking to start riding. Obviously I have to do my CBT but do I have to get an A1 before an A2? The website says that you can get direct access if you're over 19 to the A2 license, so I should just be able to skip the A1 license, right?
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Apr 12, 2013 20:02
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n8r posted:The problem with early EFI and the jerky/surging you would experience had something to do with the range of fuel an injector can spit out. When you need that teeny little bit of fuel at cracked open throttle all the way to lots of fuel at WOT stuff gets hard to setup. This was solved on some bikes by going to two injectors per intake so you had one smaller one and one larger one. Not sure how that gets solved these days, maybe injector tech has just gotten better. You might be able to shed some light on what the purpose is of the secondary throttle butterflies on my SV's intake. They don't appear to be directly proportional to throttle load/RPM (granted, my scientific analysis consisted of giving it a rev with the tank off to see) and they're operated by the ecu. Is this just to try make the engine smoother at low revs because of v-twinnyness? What would happen if they weren't there?
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Apr 12, 2013 21:01
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Slavvy posted:You might be able to shed some light on what the purpose is of the secondary throttle butterflies on my SV's intake. They don't appear to be directly proportional to throttle load/RPM (granted, my scientific analysis consisted of giving it a rev with the tank off to see) and they're operated by the ecu. Is this just to try make the engine smoother at low revs because of v-twinnyness? What would happen if they weren't there? The secondary buterflys provide the same function as the vacuum controlled slides on the R6. They "lag" behind your throttle input, to smooth out transitions. It's not a low rpm thing, it's a small throttle thing. It's one of the techniques used to compensate for the "trouble off idle" I was talking about.
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Apr 12, 2013 21:12
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