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Post by chaslittell on Oct 14, 2011 15:50:05 GMT -6
Rich: Wow great post on the emission crud. I don't think I want that big a project unless (like you had) I have a malfunction that it would repair. I had to strip the plastic on my MC-16K retro to get at the valves when I bought it last week; the original owner sold it for a song after owning it for a month and 100 miles--two reasons, he decided he liked scooters and moved up to a bigger engine to suit his rural location, and: It wouldn't start when hot! I guessed it was the vavlves, and I was right. This afternoon I set the low A/F mix a bit more rich, and it seems to idle well enough now. The idle is slower until it's good and warmed up--it's in the 50s today--but I think that's probably about right, summer weather will balance things out. This was purchased last weekend for my wife, after I found myself having so much fun with the MC-75 I bought a month ago. It needed the valves opened up as well, but it ran ok. Once I had them side-by-side, I realized the 75 was missing an exhaust manifold cap nut, much louder than the 16! But, regarding the 16's plastic--we should sell refit kits to make these plastic bodies accessible!! I couldn't believe the grief, I thought the 75 was bad but whew!! I would like to recheck the valves once they get seated, but $  # if I'm going to mess with that plastic again until I darned well HAVE to. Oh, and mine does have the floorboard tank; I assume this means it has some kind of vacuum fuel lift or something, that the gravity feeds wouldn't need. The fuel filler trap door is screwed to the side shells from the inside, maybe if I had gotten the floorboard up first the whole shell assy would have lifted off in one piece? I bet that's why I had so much trouble now that I think about it. Is it typical that the floorboards come out first to free the other panels? And yes, the "choke" does function, I could tell when it kicked off after a few mnutes. |
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Post by chaslittell on Oct 14, 2011 8:45:21 GMT -6
Folks: Thanks again for the responses. I think I will search "remove emissions" for one thing. The dip stick question is no problem, since I don't get any foaming with the unscrewed measure, and more is better when it comes to oil, especially for an air-cooled engine methinks. Re. low spd A/F mix: This morning was cool, and I had to crank a good 20 seconds with the engine sputtering before it would idle--obviously I have it set too lean. I'll fix that. Next question, many references say the plug condition is a good indicator of this setting, but how can that be if it only affects the idle and low speed mix? 98% of the time I am mid to max throttle, and it seems like that would determine the plug condition. Just wundrin'. Oh, and speaking of max throttle--lots of folks comment that running max is not good for the engine--really? It feels like it LIKES to be turned loose! Are folks just assuming that max running is bad? Just curious since my commute is about 40% wide open to keep up with traffic. Thanks again--Chas in Dayton
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Post by chaslittell on Oct 13, 2011 4:24:59 GMT -6
Great manual Rich. Makes me want to do $2000 worth of rebuilding on a $650 scooter. I guess I can't count labor cost if I do it myself though. Seriously though, one thing stands out: The manual specifically says to screw the dipstick in to get a good reading; almost all other references I find (including my owner's manual I think) say the opposite. Also the illustrated bike has a manual petcock. And of course it isn't a C.A.R.B. emissions set up. Add all this up and I think the publication is years old. In turn, this makes specs, like carb A/F nominal setting, suspect. I wonder if there is a no-kidding short/medium/long RY6 service manual out there with verified current info? Again--Thanks! Keep up the good work.
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Post by chaslittell on Oct 12, 2011 13:03:58 GMT -6
Thanks folks. But: My question remains--adjusting the A/F continues to slightly raise RPM, while the links you provided suggest there should be a setting from which the RPM will fall off no matter which direction you adjust. QUESTION also, where would I obtain a service manual for either of my scooters--though both (MC-16K and MC-75) are 2011 models and likely have identical drive trains. I would like a definitive spec on what the "factory" carb A/F setting is, as I have read 2 turns, 2.5 turns, and others--perhaps different for different carbs? I was given parts manuals and other lit which I think will tell me the carb model, maybe I can google that....Chas
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Post by chaslittell on Oct 12, 2011 10:52:57 GMT -6
Hi Folks: I don't see this specifically, so I will shout out for assistance: My new 150cc (MC-16K)'s low speed air/fuel adjustment stumbles and runs slow until the screw is just under 2 turns out, then picks up and runs smooth. However, I can get another 10 or 20% rpm's by continuing to run the screw out, another 1 or 2 turns. It seems, in engineering terms (?), to have a "knee" at around 1.75 turns below which adjusting makes a big difference, and after that, continuing to adjust only provides slight but noticable improvement.
I assume that this "knee" around 1.75 turns, or just past it, is where I want to set it. But, am I wrong, should I continue to adjust for the absolute highest rpm? That's a lot of adjustment for a little improvement. I don't want to waste fuel, but I also don't want to burn the poor thing's innards running too lean. Performance is not an issue, it seems to run fine regardless.
I hope this is clear...opinions?
PS: The MC-16K (bought for the wife) is a great running 10"-wheel scoot. I had no trouble riding it home 100 miles on the two-lane roads, it kept up with most traffic fine. The previous owner dumped it with 100 miles because it wouldn't start hot, but that was a simple valve adjustment. What a pain in the rear though to get the plastic off to get at those valves!
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Post by chaslittell on Oct 9, 2011 21:53:58 GMT -6
Y'all: I bought a 2011 150 MC-75 a month ago. I love it. But it was delivered with the valves at zero (or minus!) clearance. I set them to .004". Then yesterday a I bought the wife an MC-16, "vintage" Vespa style 150, 30 days assembled 150KM sold cheap 'cause it wouldn't start when hot. Guess what? It was the valves, again zero or less clearance. I had to drive it home, 100 miles (whew, what fun, thru the Cinci ghettoes at sunset!), and hope it was the intake not exhaust bleeding compression when hot. 300KM on a tight exhaust might be enough to burn the valve (opinions?). But now it is set and runs like a top. 10" wheels accelerate faster than 13. Anyway, SET YOUR VALVES FIRST THING ON DELIVERY!
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Post by chaslittell on Oct 9, 2011 14:16:53 GMT -6
SOLVED. Bottom runner panels holding foot plates had"slide" tabs. Slide forward, pull down--off it came.
Now, tow xmas wishes--1. Valve setting fixes hot start problem. 2. I can remember how the H I got all this plastic off!
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Post by chaslittell on Oct 9, 2011 14:08:46 GMT -6
Y'all: Banged knuckles all day trying to get body panels from the front of the engine; everything seems to come off easy except the front wrap-around panel I need off! Well not easy but at least no broken bits.
My scoot is new, 200 miles, but won't start when hot and has no valve tic sound so I am fairly sure I just need to set vavles...anybody happen to have experience accessing the valve cover on this particular model?
Thanks--Chas in Dayton
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Post by chaslittell on Aug 31, 2011 10:59:02 GMT -6
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Post by chaslittell on Aug 31, 2011 5:09:38 GMT -6
I sold my BMW K100LT tour bike, and decided to move up to a Roketa 75 (actually back probs keep me from long rides so this seems a good compromise.) It was ordered from SuperiorPowerSports.com last week, and given "warehouse backup" issues, is supposed to be delivered next week with the "free PDI."
Does anyone have experience with this 2011 model 75? Does it have improved mfg standards, better hoses or electrical hardware, any other hopefully pleasant surprises for my owner PDI? I understand that there should be SOME differences from the 2008 models, and I would appreciate a good discussion of this subject. And of course general comments on the 2011 75 as well.
Thanks all--Chas in Dayton
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# if I'm going to mess with that plastic again until I darned well HAVE to. Oh, and mine does have the floorboard tank; I assume this means it has some kind of vacuum fuel lift or something, that the gravity feeds wouldn't need. The fuel filler trap door is screwed to the side shells from the inside, maybe if I had gotten the floorboard up first the whole shell assy would have lifted off in one piece? I bet that's why I had so much trouble now that I think about it. Is it typical that the floorboards come out first to free the other panels?