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Jazzzzz posted:Someone correct me if I'm wrong: in a gravity fed system with no vacuum so the petcock is basically just a ball valve, if the petcock is left open and the carb's float valves don't seal, you'll end up with gas flowing out of the carb's overflow tube and puddling under the bike. If that overflow is blocked, fuel will end up pooling in the intake or the motor, whichever is lower It's 50/50 whether you have a good design and it just empties the tank through the overflow, or a bad one that empties it into the airbox and engine. Also: vacuum taps are no defence against this because lots of them don't really close so much as reduce flow to a tiny trickle which, given enough time, will eventually build up enough volume above the floats to force one open. Turn your poo poo off if it gives you the option.
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Sep 20, 2021 19:08
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For sure, I just forgot to last night, again, and this morning wondered what series of events would turn a forgetful mistake into a sump full of diluted oil. I'm sold on the whole "use a trusty manual petcock" concept.
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Sep 20, 2021 19:45
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A manual fuel petcock is completely dead simple to use and has almost nothing in it that can break, and vacuum-driven automatic ones always struck me as just some dumb extra poo poo like an electronic automatic day/night rear view mirror that NOBODY NEEDS and which just adds an extra potential point of failure. Ugh.
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Sep 20, 2021 19:52
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Definitely a "solution in search of a problem."
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Sep 20, 2021 21:01
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Going to convert it to post-apocalypse mad max bike and get rid of all features. Kickstart here I come  e: not a sarcastic post
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Sep 20, 2021 21:43
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Kick start only with an entirely AC electrical system and a carb is the purest and best form of bike. If I could get an i4 or v2 like this in a decent chassis I would have one already.
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Sep 20, 2021 21:48
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Are/were there any i4 engines with kick start?
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Sep 20, 2021 22:06
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Cb750, possibly others idk. The kwaka 2t triples were kickers, as we're the rgv500 and rz500 (square four, v4, both with two crankshafts).
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Sep 20, 2021 22:09
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Seems like something you could build easily enough with enough gumption, then just carry around a cordless electric ratchet to turn it over if it's too much work to fit a kick lever.
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Sep 20, 2021 22:28
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Idk, kicking over 13:1 compression is pretty hard even if you're only doing 250cc at a time. I'd still want to try though. Something like a cb400 or fz6 would probably be the sweet spot for ease of use.
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Sep 20, 2021 22:35
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CB400F had a kick start. Some homeless dude outside my apartment had one, straight piped of course. It took him like 5 minutes to kick it over each night. They also had a 5-series and a 30’ class A motor home. I still don’t understand what was going on there.
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Sep 20, 2021 22:41
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The kickstart on the SR400 is pretty simple once you get the hang of it. However at almost 400lbs and putting out a massive 22hp it’s terrifyingly slow
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Sep 20, 2021 23:10
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I think it’s entirely a gimmick for my daily use, but I just really want a kickstart. Pretty sure I’ll add one when I get bored.
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Sep 21, 2021 00:34
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Slavvy posted:Kick start only with an entirely AC electrical system and a carb is the purest and best form of bike. If I could get an i4 or v2 like this in a decent chassis I would have one already. How about magneto ignition and no electrical system at all
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Sep 21, 2021 00:42
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Sagebrush posted:How about magneto ignition and no electrical system at all Problem with magneto is it restricts you to a fixed/barely variable spark advance. While I like the elegance and mechanical simplicity, the resulting engine is never fun or characterful, they all just feel like you're riding various sizes of lawn mower. Points are the next step up but they're horrible and janky, I would rather a serviceable CDI where I can swap out individual blown components.
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Sep 21, 2021 00:54
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Slavvy posted:Kick start only with an entirely AC electrical system and a carb is the purest and best form of bike. If I could get an i4 or v2 like this in a decent chassis I would have one already. Behold, the ultimate Slavvy-endorsed motorcycle: 
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Sep 21, 2021 01:42
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I mean, the rgv and nsr are the same thing but better and I used to own one of those. But you can hardly feel any v-twin character, every two stroke with an expansion chamber feels exactly the same, the capacity just changes the level of thrust, peak power is always 10-12000rpm regardless of configuration. It's just not that interesting, beyond the inherent fun of riding a peaky stroker. I would very much like to have a go on an old H2 as I suspect the relatively bad port design and air cooled foibles would make for a really interesting experience.
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Sep 21, 2021 01:49
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Slavvy posted:Problem with magneto is it restricts you to a fixed/barely variable spark advance. While I like the elegance and mechanical simplicity, the resulting engine is never fun or characterful, they all just feel like you're riding various sizes of lawn mower. Points are the next step up but they're horrible and janky, I would rather a serviceable CDI where I can swap out individual blown components. Wait a second... what about those really old motorcycles that had an ADVANCE/RETARD setting right on the handlebar? If that hand control could just be automated, wouldn't it be possible to have variable ignition timing in a magneto system?
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Sep 21, 2021 03:00
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It's completely possible to have a variable spark advance with a magneto using a mechanical advancer. (The vast majority of those systems are used with ignition points, but the principle can also be applied to a magneto). This system is only dependent on RPM, not throttle position or engine load as an electronic ignition map can be, which I assume is what Slavvy considers to be "barely variable." Sagebrush fucked around with this message at 03:41 on Sep 21, 2021 |
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Sep 21, 2021 03:37
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Yeah that's the thing. Advance based on rpm changes is nearly but not entirely useless. A cdi can be tps-influenced, but the main advantage to a cdi is you can have an advance curve which means you don't need variable anything, you can just tailor the advance to the particular engine. You can somewhat approximate this with a vacuum advance system but again, terrible garbage system sort of kind of doing the job vs doing it perfectly with no moving parts. Ultimately all you're doing with an AC cdi is moving the generating component out of the spark control component, it's like a magneto with all the parts scattered across the bike. I also like the Harley system where the cdi is the ckp sensor, just a small box sitting on the end of the cam doing everything.
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Sep 21, 2021 03:51
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 Hmm is this kinda normal? I got a catalytic baffle from China. The exhaust isn't glowing entirely, just the honeycomb. Normally can't see a cat. I decided to go down a jet size and it glowed a bit less. Any lower and the bike will start getting a performance hit from prior testing. Honeycomb substrate probably also intentionally can't heatsink well, maybe it's not just unburnt fuel. Guessing it's normal and it's kinda neat. Can't reallllly tell without an O2 sensor probably at this point. Not really a help me tune my bike question. If it's not normal I think at this point I would need to futz with the air intake volume before trying to go down in jet size. The bike feels a bit better than a stock Grom, having been on one. SSH IT ZOMBIE fucked around with this message at 18:35 on Sep 21, 2021 |
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Sep 21, 2021 18:11
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That reminds me, I had an exhaust question as well. I think my exhaust pops more than it used to under engine breaking (2001 sv650). What are likely causes? Exhaust blow allowing air in and sunburnt fuel to burn?
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Sep 21, 2021 18:48
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Megabook posted:That reminds me, I had an exhaust question as well. I think my exhaust pops more than it used to under engine breaking (2001 sv650). What are likely causes? Exhaust blow allowing air in and sunburnt fuel to burn? Probably the exhaust losing packing/baffling from age and rust, could also be slight clogging of the pilot circuits leading to leaner idling. Generally they pop when running lean.
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Sep 21, 2021 18:55
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I think what you are describing is decel popping. Some people like it. A little might be normal. A lot it's worth tuning your carbs and normal maintenance like air filter cleaning if your bike is carbed which I think yours is.
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Sep 21, 2021 18:57
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SSH IT ZOMBIE posted:
I think it's normal. The honeycomb in the stock muffler on my bike does it too, even after re-jetting and getting it running well.  It was a surprise when I noticed it though. Exhaust was sounding funny on the way home from work, then I noticed that when I was listening for a leak. The change in sound turned out to be a hook on my bungee net dangling and flapping around in front of the exhaust outlet
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Sep 21, 2021 21:02
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Catalytic converters don’t work unless they’re glowing hot, so that’s normal.
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Sep 22, 2021 01:30
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SSH IT ZOMBIE posted:
That’s literally what cats do in the process of doing their job. You just can’t see them doing it, normally. More unburnt fuel will make it glow hotter.
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Sep 23, 2021 00:27
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Fun fact: you can buy flameless propane heaters that work on exactly the same principle. It's just a bunch of tight platinum-coated steel mesh in a tube, propane is passed through, and the gas is catalytically cracked into carbon dioxide and water, releasing the energy you'd get from burning it but without a flame. You have to preheat it to cherry-red (usually with a built-in torch or something) to get the reaction going, but once it's hot it's self-sustaining.
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Sep 23, 2021 00:33
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I think the propane powered mosquito trap I just bought must work like that
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Sep 23, 2021 00:40
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SSH IT ZOMBIE posted:I think what you are describing is decel popping. Some people like it. A little might be normal. A lot it's worth tuning your carbs and normal maintenance like air filter cleaning if your bike is carbed which I think yours is. I really love hearing that pop when I engine brake a bit harder in second.
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Sep 23, 2021 12:21
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Megabook posted:That reminds me, I had an exhaust question as well. I think my exhaust pops more than it used to under engine breaking (2001 sv650). What are likely causes? Exhaust blow allowing air in and sunburnt fuel to burn? During engine breaking you're almost certainly going to hear some unusual noises. Kind of a minor issue in context though.
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Sep 23, 2021 21:52
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Sagebrush posted:During engine breaking you're almost certainly going to hear some unusual noises. Kind of a minor issue in context though. An acquaintance of mine described his 70s Triumph as suffering from engine-rich exhaust which still makes me chuckle like 20 years later.
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Sep 23, 2021 22:05
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I haven’t deleted the weird air injection thing from my KLR, the predictable pop it helps produce on decel is the only satisfaction I get from its exhaust.
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Sep 24, 2021 02:00
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If I want to pull a swingarm, is putting the front wheel into a chock and throwing a bike jack under the engine part of the frame sufficient or do I need to figure out some mcgyger way to suspend my subframe? I could probably get away without the front chick but it helps keep the bike upright and takes zero additional effort.
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Sep 27, 2021 00:05
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Martytoof posted:If I want to pull a swingarm, is putting the front wheel into a chock and throwing a bike jack under the engine part of the frame sufficient or do I need to figure out some mcgyger way to suspend my subframe? I could probably get away without the front chick but it helps keep the bike upright and takes zero additional effort. If this is the drz you'll find you barely even need to chock it, it'll be pretty well balanced on the flats if you're careful. Just remember it'll get more front heavy when you take the rear wheel out. If it's the 650 you'll need to properly clamp the front wheel cause they haven't got a flat bottom I don't think . Remember it's easier to move the jack up and down than trying to levitate the wheel or swingarm when you're assembling.
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Sep 27, 2021 00:16
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It’s the DRZ and I agree, mostly stable but I just want that little extra stability in case the swingarm pivot is super torqued or gummed in place and I have to do something ugly. I’ve had the rear wheel off so logically I was like 99% sure I didn’t need to support anything else to pull the swingarm but I’ve been known to overlook the obvious. Thanks 
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Sep 27, 2021 00:41
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About to throw in a towel on this stupid R1 clutch. For review it's a 2003 Yamaha R1 engine in a lotus/caterham style car. The clutch cable, more the grasping mechanism, failed a few months ago. After getting zero response from Motion Pro or any of the other companies that make cables I bought the stuff and made my own. Once I had a new cable on it appeared the clutch pack had frozen so I replaced that with a EBC unit (https://www.sportbiketrackgear.com/ebc-yamaha-yzf-r1-99-03-srk-race-sport-series-clutch-kit/). Now the pressure plate isn't moving.... -I've had the stack apart several times verifying the right order, the directional first mini plate is also facing the right direction. -Everything is torqued to spec, verified with 2nd torque wrench. -I've tried the pivot arm in every position, it doesn't make a difference. -I'm actuating things by hand at the arm to eliminate the possibility for a cable issue. -I can see the pullrod moving so the teeth are grabbing (no damage to teeth on either). -Clutch spring plate thing is the right direction -In bike engine cars two clutch springs are used to assist in clamping force, running one stock and the EBC unit. Went back to one OEM spring, same issue. -I'm unsure if this was happening before I pulled it apart, didn't think to look as frozen clutch is a common-ish R1 issue. Working space  Pack  The only resistance felt moving the lever is the external return spring and it only seems to be taking up slack in the pullrod instead of doing anything useful. So what could be causing the pressure plate to be completely stuck in place? NitroSpazzz fucked around with this message at 18:56 on Oct 3, 2021 |
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Oct 3, 2021 18:50
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Nothing is stuck in place, you just haven't gotten the cover on there correctly. You have to pre-rotate the release arm about a quarter of a turn so that when it hits the toothed pushrod, it 'climbs' into position when you clamp the cover down. It usually takes me 2-3 tries to get it right and yeah, if you get it wrong you'll often end up with lots of travel and no actuation. Nothing you could get wrong with the actual clutch stack would cause it to have no resistance at the lever, your issue is almost certainly actuation and not getting the thing lined up correctly is extremely common on r1 and r6.
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Oct 3, 2021 19:05
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Martytoof posted:It’s the DRZ and I agree, mostly stable but I just want that little extra stability in case the swingarm pivot is super torqued or gummed in place and I have to do something ugly. I’ve had the rear wheel off so logically I was like 99% sure I didn’t need to support anything else to pull the swingarm but I’ve been known to overlook the obvious. Thanks If you're in a garage you could attach a ratchet strap to the ceiling and loop it around your subframe as a safety measure. Strapping to the ceiling is a pretty legit way to lift but can lead to some awkward situations if you don't have an assistant for raising and lowering.
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Oct 3, 2021 20:02
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Slavvy posted:Nothing is stuck in place, you just haven't gotten the cover on there correctly. You have to pre-rotate the release arm about a quarter of a turn so that when it hits the toothed pushrod, it 'climbs' into position when you clamp the cover down. It usually takes me 2-3 tries to get it right and yeah, if you get it wrong you'll often end up with lots of travel and no actuation. Nothing you could get wrong with the actual clutch stack would cause it to have no resistance at the lever, your issue is almost certainly actuation and not getting the thing lined up correctly is extremely common on r1 and r6. Wow...how many times did I take that stupid thing apart. I dropped back to one spring and found the magic spot, I had underestimated how much force it took to actuate. I could barely get it to move with only one spring and vice grips on the arm, there's no way I could have managed with two. Reinstalled the second, put it back in the magic spot and messed with the cable for a bit to take out most of the slack. It worked! Think I'll make another cable and I'd still like to redesign the holding mechanism on the pedal. Thanks Slavvy.
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Oct 3, 2021 20:31
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